Long-Chain Polyunsaturated Fatty Acids in the Developing Central Nervous System

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Long-Chain Polyunsaturated Fatty Acids in the Developing Central Nervous System Susan E. Carlson  |  Carol L. Cheatham  |  John Colombo

INTRODUCTION The brain and retina contain large quantities of n-3 and n-6 longchain (20 and 22 carbons) polyunsaturated fatty acids (PUFAs), particularly docosahexaenoic acid (DHA; 22:6n3) and arachidonic acid (AA; 20:4n6).1,2 During the last intrauterine trimester3,4 and the first 18 months of postnatal life, DHA and AA accumulate in neural tissue at a high rate supported by selective placental transfer of DHA and AA from the mother to the fetus5,6; transfer of preformed DHA and AA from human milk consumption,7,8 and synthesis of DHA and AA from the dietary essential fatty acids, α-linolenic acid (18:3n3), and linoleic acid (18:2n6), respectively.9-13 The first studies of infants fed formulas, then not containing DHA and AA, found lower levels of DHA and AA in red blood cell and plasma lipids,7,8 and DHA in brain13,14 compared with the levels in infants fed human milk, which suggested that dietary DHA and AA might be important and that synthesis of these fatty acids might not meet the needs for DHA and AA for developing retina and brain. Furthermore, infants born preterm had lower brain DHA levels than infants born at term, reinforcing the importance of the last intrauterine trimester for the DHA status of the newborn.15 It has been estimated that the third-trimester fetus accumulates approximately 40 to 60 mg of DHA per kilogram each day.16 Carnielli and colleagues17 quantified DHA synthesis in 1-monthold infants born preterm and showed they could synthesize only about 12.6 mg/kg per day, with synthesis falling dramatically to approximately 3.2 mg/kg per day by 3 months of age. Even though the amount of synthesized DHA that was due to brain accretion could not be quantified, these results are further evidence of the importance of maternal DHA transfer during gestation and breast-feeding as the endogenous conversion of α-linolenic acid to DHA does not meet the preterm neonate’s needs for optimal DHA accumulation. The rate of endogenous synthesis of long-chain PUFAs (LC-PUFAs) from their precursors depends on many complex factors such as genetic status,18 balance of fatty acids,19 and mode of feeding.20 Even before there were studies of LC-PUFA biosynthesis, randomized studies of DHA and AA supplementation in preterm infants were conducted. The hypotheses tested were (1) erythrocyte DHA and AA are biomarkers for DHA and AA status, (2) lower status can have functional consequences, and (3) function can be improved or optimized by DHA and AA supplementation. The functional outcomes chosen for early studies were those linked to lower brain DHA levels in animals: retinal electrophysiology,21-23 visual acuity,24 and various measures of cognition.25-33 A major difference between the animal models and human studies was that animals were fed diets lacking α-linolenic acid, the essential fatty acid precursor for DHA, whereas infant formula contained α-linolenic acid. In most animal models, brain DHA was extremely depleted, with a reciprocal replacement by a long chain n-6 fatty acid, docosapentaenoic acid (22:5n6).32,34 In contrast, the brain DHA level in human term and preterm infants was estimated to be reduced by 20% and 50%, respectively.13,15 In the first studies of infants born preterm, researchers found higher visual acuity and more mature retinal physiology with DHA-supplemented formula (there were no sources of AA

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available at the time).35-37 These results led to a number of randomized trials in which the growth and development of term and preterm infants fed formulas supplemented with DHA and AA were compared with those fed formulas without DHA and AA. These studies have been the subject of a number of early38-42 and more recent42-46 reviews. Single-cell oil sources of DHA and AA were added to commercially available formula beginning in 2002, after the U.S. Food and Drug Administration gave singlecell oils generally recognized as safe (GRAS) status (Federal Register, 62 FR 18939-18964). The Docosahexaenoic Acid Intake and Measurement of Neural Development (DIAMOND) trial, the only randomized controlled dose-response study of infant formula LC-PUFAs, was initiated after the addition of DHA to infant formula in the United States became routine, and included the same amount of AA in all three DHA-containing formulas.46 The primary outcome of this study was to determine the effects of LC-PUFAs on visual acuity of term infants at 12 months of age.46 The study included additional aims to study child development at the individual study sites in Dallas and Kansas City. The results from the trial, now available out to age 10 years, will be discussed later in this chapter. A 2014 European Food Safety Authority opinion on the compositional requirements of formula for infants older than 6 months of age states there is not a need for AA in these formulas.47 The opinion is being contested48; whereas it is true that many studies emphasize questions about DHA, most interventions combine DHA with AA, and so any benefits shown must be attributed logically to both LC-PUFAs. There are other reasons to provide a balance of these fatty acids in infant formula, including the fact that AA concentration exceeds that of DHA in both human milk and brain phospholipids,4,13,14 and a proper balance of n-6 to n-3 fatty acids has been shown to be related to optimal cognitive abilities.49 In the fourth edition of this book, we mentioned the need for more studies that look at cognitive and other brain-related functions in childhood and more studies of the role of LC-PUFA supplementation during pregnancy on infant and child development. A number of subsequent reports have provided cognitive results for children, and several research groups continue to report follow-up data from cohorts that were perinatally exposed to LC-PUFAs. Information from recent reports on the relationships of genetic polymorphisms in the fatty acid desaturase (FADS) genes to LC-PUFA synthesis and cognitive outcomes is added to this edition. In this edition we have dropped the word retina from the title. There are no recent studies of retinal function in infants who received LC-PUFA supplementation. Even at the time of the third edition, the only evidence of deficiency on retinal function came from a reversible effect on retinal electrophysiology in preterm infants fed a formula with very little α-linolenic acid.50 The essentiality of DHA for retinal function is well established from studies in nonhuman primates fed diets deficient in n-3 fatty acids.51 However, developing infants appear to acquire sufficient DHA in the retinas under normal circumstances of pregnancy and early feeding. As already mentioned, it has been suspected for many years that this may not be the case for the brain.



Chapter 38 — Long-Chain Polyunsaturated Fatty Acids in the Developing Central Nervous System

We removed a large section of the chapter devoted to the effects of n-3 fatty acid deficiency on animal behavior but retain the references for those who are interested in this work, which was important in providing the rationale for human studies. Animal models with reduced brain DHA levels provided the basis for the choice of outcomes in human studies and continue to be important for this reason, as well as to help us understand the mechanisms by which changes in brain LC-PUFA levels can influence function. Animal work will continue to be important to learn the mechanisms by which perinatal LC-PUFA exposure programs cognitive outcomes long after increased exposure has terminated. Behavioral domains include sensory functions, motivation or arousal, learning, cognition, and motoric functions. Wainwright52,53 reviewed the principles governing animal models of behavior and the evidence from these models that lipids influence behavior. We include references to the previously cited material on sensory,21,22,29,52-55 cognitive,25-27,33,52,53,56-67 and motivation/arousal,68-75 and cite other animal research where it is relevant to the topic discussed. Although there have been several recent metaanalyses and systematic reviews of LC-PUFA supplementation of infants, this type of analysis is not well suited to studies of nutrients where there are large differences in intake among populations. DHA and AA are nutrients, and the goal of good nutrition is for diet or diet and supplements to provide a safe and adequate amount of nutrients for optimal health. A basic flaw of metaanalyses and systematic reviews for studies of nutrients is that they combine the results from studies conducted in different cultures with very different LC-PUFA intakes to determine if there is a need for more of a nutrient. With respect to DHA, there is bias toward a conclusion of no effect for supplementation because most trials have been conducted in fish-eating populations rather than in world populations with low DHA intakes. However, a number of trials have been conducted in the United States, where dietary DHA intake of adults is very low (~48mg of DHA per day).76 If used to define public policy, the results of metaanalyses can be harmful to individuals and populations with an inadequate intake of that nutrient. We have already expressed our concern about the primary outcome on which recent metaanalyses/systematic reviews on this topic are based.77 A 2012 publication addresses the need to study groups that are deficient.78 Another publication illustrates the presence of differences in DHA status within a cohort of pregnant women and relates status to functional outcomes in the perinatal period.79 To truly understand the effects of fatty acids, future research should focus on controlling variables not previously considered, such as genetics, nutrient balance, and synergistic effects of nutrients, when considering whether supplementation of the infant diet with fatty acids has a positive effect on development. Most importantly, the samples chosen for study should have an initial, fundamental need for supplementation. Quite simply put, if remediation is not needed, supplementation should not be expected to have an effect.

FACTORS THAT AFFECT MATERNAL   AND INFANT LC-PUFA STATUS Red blood cell DHA is generally considered a reasonable marker for brain DHA accumulation in the perinatal period, even though the evidence is very sparse for such an assumption. However, this assumption is not made in the case of AA, even though like DHA, AA is preferentially transported across the placenta.6 Maternal DHA status is highly variable, and variable intake is the most influential factor in the amount of DHA transferred to the infant. Maternal DHA status also affects the transfer of DHA to the infant during lactation.80-85 Haggarty86 illustrated the importance of maternal DHA intake and the duration of gestation on the differential accumulation of DHA by the fetus. He reported

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that term infants accumulate larger amounts of DHA in adipose tissue with time in utero and with higher maternal DHA intake. In 2012, Kuipers and colleagues87 questioned the basis for some of Haggarty’s estimates of adipose tissue DHA concentrations. Although Kuipers and colleagues confirm an overall trend to adipose DHA accumulation in the last trimester of gestation, they found extreme variability in individual DHA accumulation in white adipose tissue at all gestational ages from 25 and 42 weeks. The size of the adipose tissue pool of DHA at birth could be a variable influencing postnatal DHA status.86 The only large multicountry comparative study included pregnant women from the Netherlands, Hungary, Finland, England, and Ecuador. The researchers reported significant differences in the concentrations of DHA in maternal plasma, most likely due to differences in DHA intake among these countries.80 As mentioned previously5,6 and discussed in Chapter 34,88 there is selective transfer of DHA and AA across the placenta, and much is known about the specifics of fatty acid transport. Despite the relationship between maternal DHA status and newborn DHA status,6,80,83 however, only 25% of the variance in DHA status of newborns is predicted by maternal DHA status.89 Gestational age is also a predictor of umbilical cord blood DHA levels, but no predictor has been found for most of the variance in umbilical cord blood DHA levels.90 Pregnancy has been shown to alter the amount of DHA in circulating blood lipids and red blood cell phospholipids. Al and colleagues81 observed that the levels of phospholipid DHA in maternal plasma and red blood cells increased in early pregnancy, regardless of the initial levels of red blood cell DHA. These data suggest that DHA is mobilized during pregnancy for transfer to the fetus. However, the same group of investigators reported increased levels of maternal 22:5n6 relative to DHA, from which they concluded that pregnant women’s systems lag behind with respect to DHA production and transfer to the fetus.82 Van Houwelingen and colleagues91 observed similar relative increases in the ratio of 22:5n6 to DHA in infants born preterm, further suggesting that an increase in ratio of 22:5n6 to DHA indicates inadequate DHA synthesis or accumulation. Thus even though it appears that DHA is mobilized during pregnancy, the amount may not be sufficient to provide for optimal fetal development. The number of prior pregnancies is inversely related to maternal DHA status, suggesting that maternal stores can be depleted by repeated pregnancy and/or lactation.92 A number of recent studies show the relation between single nucleotide polymorphisms in the FADS gene complex and lower AA and/or DHA status.18,93-95 The FADS gene complex contains the genes that govern the rate-limiting enzymes of the fatty acid metabolic pathways. DHA supplementation improves maternal DHA status in women who carry only the minor alleles FADS1 rs174553 and FADS2 rs174575, but minor allele carriers of both these genes experienced a significant drop in AA status with DHA supplementation.95 Just as a woman’s DHA status during pregnancy affects transfer of DHA to her fetus, it also influences DHA transfer to her newborn in human milk. Connor and colleagues96 and Harris and colleagues97 first showed that increasing consumption of DHA increases the amount of DHA transfer to milk and the DHA status of the infants. The DHA content of human milk as a percentage of total fatty acids differs within and among populations. The extremes of milk DHA proportions that have been reported are 0.02% in vegans98 and 2.4% in women from China who consume a diet high in fish.99 Human milk DHA in most groups studied tends to fall on the low side of this range.100,101 Like DHA, the reported average amount of AA in human milk differs among cultural groups, from 0.2% to 1.2%.102 However, the average AA proportion in the milk of most populations falls within the range of 0.4% to 0.6%, and the average linoleic acid content ranges between 10% to 17% of total fatty acids.92,101-103

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An observational study by Molto-Piugmarti and colleagues104 linked lower milk DHA content to genetic polymorphisms of two FADS single nucleotide polymorphisms, FADS1 rs174561 and FADS2 rs174575. In another correlational study, lower DHA, AA, and n-3 docosapentaenoic acid (22:5n3) levels were reported in the milk of women who were homozygous for the minor allele at rs174575; women who were homozygous for the minor allele as well as the heterozygotes at rs174553 had lower product-toprecursor ratios in both the n-6 pathway and the n-3 pathway.105 In a randomized controlled study of DHA supplementation, women assigned to DHA who were homozygous for the minor allele FADS2 rs174575 had lower DHA levels in milk compared with other genotypes, although their DHA status was equivalent with DHA supplementation.95,106 The results of the observational studies and the randomized controlled trial suggest that women who are homozygous for minor alleles at FADS single nucleotide polymorphisms have limited transfer of DHA to human milk, but the reason for this is not known. During gestation, transfer of the 18-carbon essential fatty acids to the fetus appears to be limited because linoleic acid levels in circulating phospholipids of umbilical cord blood are low.107 High linoleic acid exposure may not be optimal for early brain development.108 Infants born preterm fed formulas with high amounts of linoleic acid have very low nervonic acid (24:1n9) levels in their red blood cell sphingomyelin for the first 6 months of life and much less than infants born at term until the corrected age of 12 months.109 This important fatty acid in brain white matter is replaced by adrenic acid (24:2n6), which is presumably synthesized by repeated elongation of linoleic acid (18:2n6). If this change in fatty acids is reflected in the fatty acid composition of brain myelin in preterm infants, it could result in white matter that is functionally quite different from that of infants born at term. Of note, a 2013 report from Sweden compared donor human milk with milk of women delivering an infant before term and found seven-fold higher nervonic acid levels in preterm human milk, but also approximately half as much linoleic acid as in donor milk.110 In the United States dietary linoleic acid intake has increased dramatically in the past 60 years,111 and the content of linoleic acid in human milk reflects maternal linoleic acid intake. Several studies in infants born at term link higher linoleic acid exposure to adverse brain development: maternal linoleic acid concentration was inversely related to infant head circumference.84Two recent articles link higher linoleic acid content112 or a lower DHA to linoleic acid ratio113 in human milk to lower cognitive performance. Moreover, it has been reported that boys who consumed human milk had higher white matter quality at 8 years of age (on the basis of magnetic resonance diffusion tensor imaging fractional anisotropy) compared with boys who consumed infant formula.114 Although differences in white matter quality for the two diets were not found in girls, white matter quality in the whole cohort correlated with scores on two tests of cognitive development (the Reynolds Intellectual Assessment Scales and the Clinical Evaluation of Language Fundamentals). A DHA-deficient diet that contains α-linolenic acid does not compensate for the DHA accumulation that occurs in red blood cells, plasma, and the brain of infants fed even small amounts of DHA.12,14,36,115 In the months after birth, infants fed formulas that contain α-linolenic acid but no DHA have progressively lower amounts of red blood cell DHA,115 whereas infants fed formulas with DHA have higher concentrations.115,116 Currently, most infant formulas in the United States provide a ratio of linoleic to α-linolenic acid of less than 10 and at least 1.5% of total fatty acids (0.75% energy) as α-linolenic acid. However, formulas still contain high amounts of linoleic acid. Now that DHA and AA have been added to infant formulas in the United States, it may be time to reassess the high amount of the 18-carbon essential fatty acids in infant formulas.

LONG-CHAIN POLYUNSATURATED   FATTY ACIDS AND THE DEVELOPING HUMAN INFANT EFFECT OF DIETARY LONG-CHAIN POLYUNSATURATED FATTY ACIDS ON HUMAN INFANT LONG-CHAIN POLYUNSATURATED FATTY ACID ACCUMULATION AND STATUS The human fetus accumulates DHA during the last intrauterine trimester by maternal transfer of DHA across the placenta.5,6 The process of maternal transfer continues after birth through breastfeeding as all human milk contains DHA, albeit in variable amounts.7,8,92,103 With medical advances made over the last 35 years, infants born at the beginning of the third intrauterine trimester, and thus before in utero brain DHA accumulation, now have excellent chances of survival. Before DHA and AA were added to preterm formulas, these infants had to rely on synthesis for any additional postnatal DHA accumulation. Breast-fed infants have more DHA and AA in red blood cells than do formula-fed term infants (first shown by Sanders and Naismith7 and Putnam and colleagues8 and supported by a large number of subsequent studies). Regardless of gestational age at birth or diet (human milk or current US formula), mean red blood cell phospholipid DHA concentration is higher at birth than in the months after birth in US infants. The apparent “physiologic” decline in the red blood cell DHA content in breast-fed infants raises several questions, such as whether mothers transfer less DHA to their infants in milk than in utero, whether DHA content decreases because of enhanced utilization by other tissues, and whether this postnatal decline is unique to infants in the United States, where mothers have been shown to have milk DHA content among the lowest in the world.8,66,67,100 Lower milk DHA content suggests lower maternal to infant transfer of DHA in utero as well. The evidence for variable intrauterine DHA accumulation includes (1) a large range of normative values for DHA in umbilical cord red blood cell phospholipids of infants born preterm,107 (2) a progressive increase in maternal phospholipid DHA content throughout the last intrauterine trimester,117 (3) a decline in umbilical cord red blood cell phospholipid DHA content with successive pregnancies,86 (4) variability in brain DHA content among infants born at the same gestational age, and (5) the variable fetal concentration of DHA in adipose tissue.87 The addition of DHA from fish oil,36,108,115,118 egg phospholipids,119 and single-cell oils46 increases DHA levels in circulating phospholipids of infants, suggesting that these sources could increase DHA supply available for the brain. Conversely, infant formulas with α-linolenic acid but no DHA do not prevent the postnatal decline in red blood cell DHA content that occurs across several months of feeding; and DHA content in circulating phospholipids remains low for more than 1 year when infants consume these formulas.115,120 After birth, AA levels decline in plasma and red blood cell phospholipids. The decline appears to be physiologic. For example, AA content is higher in preterm than in term umbilical cord blood, and even after 4 to 6 months of breast-feeding, infants born at term have much lower red blood cell AA levels than is seen at preterm delivery (8.8% versus 15.7%).8,12 AA content in the brain and liver also declines during the last intrauterine trimester.121 However, breast-fed infants have more AA in red blood cell and plasma phospholipids than do infants fed formulas without LC-PUFAs, and those fed formulas with n-3 LC-PUFAs have even lower phospholipid AA levels.122 AA is the source of metabolically important prostaglandins and leukotrienes. Significant correlations have been reported between AA levels and both intrauterine growth117,123 and growth



Chapter 38 — Long-Chain Polyunsaturated Fatty Acids in the Developing Central Nervous System

in the first year of life of infants born preterm.123 In formula-fed infants, dietary DHA or total n-3 LC-PUFA content is related to lower AA levels and, subsequently, an altered balance of n-3 and n-6 LC-PUFAs in red blood cell phospholipids.122 We recently reported that DHA supplementation reduced red blood cell phospholipid AA levels only in women with minor alleles of FADS1/FADS2,95 suggesting that alterations in the balance of n-3 and n-6 LC-PUFAs with n-3 LC-PUFA intake might be much greater in minor allele carriers. The implications of this are not known but they deserve further study. In three randomized trials some reduction in growth of infants born preterm who consumed infant formula that contained fish oil DHA and no AA was found.116,123,124 In one study, the effect was limited to a lower weight for length at several ages in the first year.124 In another study, the growth effects were found only in male infants.116 Slower growth has not been found in either term infants fed formula containing DHA or in preterm infants fed formula with both AA and DHA (for a review, see Lapillonne and Carlson125). Long-term feeding of n-3 LC-PUFAs without AA could decrease brain AA accumulation and thus affect the developing central nervous system. AA concentration reportedly exceeded that of DHA in the cortex as a whole in infants who died of crib death4,13,14 and in two reports with small numbers of young children in which fractions of phospholipids were analyzed.126,127 AA concentration also exceeds or is equivalent to DHA concentration in the hippocampus and occipital cortex of infant baboons unless they are fed 0.96% DHA and 0.64% AA, in which case DHA concentration exceeds AA concentration.128 In animal models the consumption of high concentrations of α-linolenate129 and n-3 LC-PUFAs from fish oil130 decreased brain AA accumulation in rats. Wainwright and colleagues131 reported lower brain and body weights in mice beginning approximately 2 weeks after birth when they were suckled by dams fed a very low n6/n-3 ratio (0.32) created by feeding them with DHA but not AA. Arbuckle and colleagues132 reported that piglets fed a diet with 4% of fatty acids as α-linolenic acid (but not 1% α-linolenic acid) had lower brain weights and lower levels of AA in membranes of synaptosomes compared with controls. Baboon neonates fed formulas with DHA had lower DHA levels in all brain regions when fed formula with more DHA than AA (1% DHA and 0.67% AA) but not when fed formula with a 1 : 2 ratio of DHA to AA (0.33% DHA and 0.67% AA).128 There have not been experimental studies comparing diets with and without AA. Despite the lack of experimental evidence for adding AA to the diet of formula-fed infants, it is prudent to balance the addition of DHA to infant formulas with AA, as has happened with LC-PUFAsupplemented formulas in the United States and most of the world, at least until we know the optimal balance of these fatty acids for brain development. This practice may also be defended because both these nutrients are found in all human milk, albeit in variable amounts.

RETINAL FUNCTION AND VISUAL ACUITY Lower retinal and visual development were noted first in primates deficient in n-3 fatty acids,24 and visual acuity was measured by some procedure in most early infant studies.35,36,119,133,134 Retinal physiology is measured by electroretinograms. As noted previously, a diet deficient in α-linolenic acid leads to low retinal DHA accumulation in monkeys51 and piglets,132 but formulas that contain α-linolenic acid and no DHA appear to result in sufficient retinal DHA, as retinal electrophysiology is normal shortly after birth even in infants born preterm fed an α-linolenic acid (and DHA) deficient formula.50 In infants fed formulas that are not deficient in α-linolenic acid, retinal DHA content is similar to retinal DHA content in human milk-fed infants.14 Visual acuity as measured in clinical studies of DHA and AA supplementation may thus be considered to reflect brain function, as retinal function is not impaired. Visual acuity has been

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assessed by both behavioral (Teller Acuity Card) and electrophysiologic (visual evoked potential) procedures. Although studies have found higher visual acuity with higher DHA status with both of these procedures, two studies that measured visual acuity with both procedures found significant effects only with visual evoked potential.14,119 The first interventions in which DHA was added to infant formula were designed for infants born preterm because, in the absence of in utero maternal transfer, these infants were the likeliest to benefit from supplementation. Most of the early randomized trials of DHA supplementation in preterm infants were relatively small (number per group, 20 to 30) and all were conducted in the United States. All found higher visual acuity with DHA at some age in the first year of life when they compared formula without DHA with a formula with DHA.35,36,124,135 The DHA for Neurodevelopment of Preterm Infants (DINO) trial was conducted in Australia and includes the largest group of infants born preterm studied in a single randomized controlled trial. In this study the control group received approximately 0.3% of total fatty acids as DHA (similar to the amount currently in most US formulas), whereas the experimental group received 1% DHA. At a corrected age of 4 months, the group fed the higher amount of DHA had significantly higher visual acuity, evidence that preterm infants could benefit from more DHA than in current preterm formulas.134 In addition to randomized trials designed to improve perinatal DHA status, observational studies link maternal DHA status to maturer visual acuity development. For example, both Jorgensen and colleagues136 and Innis and colleagues137 reported that DHA status of lactating women was significantly related to visual acuity of their infants. A population-based cohort study suggested that maternal prenatal and postnatal intake of oily fish, a source of both DHA and eicosapentaenoic acid (20:5n3), was related to higher stereo acuity in the children at 3.5 years of age.138 Higher umbilical cord blood DHA content, representing exposure to DHA in utero, has been associated with shorter latencies of the N1 and P1 components of color visual evoked potential in 11.3-year-old children.139 This higher visual acuity may confer a cognitive advantage (i.e., accelerated development of visual acuity may facilitate development in other cognitive domains). For example, it has been shown that 6-month-old infants receiving an exclusive diet of human milk with lower levels of DHA relative to other infants in the sample were unable to differentiate between novel and familiar pictures in an electrophysiology paradigm as this age group should be able to do.140 Although acuity was not measured in that study, it is possible that the infants’ steady diet of milk with suboptimal DHA content resulted in delayed visual development, which in turn delayed visual recognition performance in this paradigm. In contrast to observational studies, several large randomized trials conducted in Australia, the United States, and Mexico have not found a benefit for visual acuity in infancy, despite supplementation of the infants’ mothers with as much as 400 to 800 mg of DHA per day during pregnancy.141-143 Most current prenatal supplements of DHA contain 200 mg. These findings raise the possibility that differences in maternal DHA status prior to pregnancy (observational studies likely reflect usual maternal DHA intake) or poorer ability to synthesize DHA may be more important to outcome than the amount of DHA consumed during pregnancy. Relevant to the existence of continued higher grating visual acuity, two studies in term infants found persistent effects of supplementation after postnatal DHA supplementation is discontinued.144,145 The DIAMOND trial found higher visual acuity at 12 months of age in infants who received DHA (0.32%, 0.64%, and 0.96%) supplementation and AA (0.64%) supplementation from birth to 12 months of age compared with those fed a control formula without DHA and AA.46 Two large multicenter trials of LC-PUFA-supplemented formulas found no effect of DHA and AA

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supplementation on visual acuity 146,147; however, the formulas used in those studies contained much less DHA than the formulas used by Birch and colleagues.144,145 Although only about half of the studies have found higher visual acuity in term infants with addition of DHA to infant formula, there is wide variation in the environments of the populations assessed, the duration of supplementation, and the sources of LC-PUFA; and many studies lack the statistical power to reject the null hypothesis.149 Early visual acuity has been linked to cognitive performance later in infancy and childhood, suggesting that early increases in visual acuity with DHA could contribute to accelerated maturation of other aspects of development over time. For example, infants in two studies born preterm and fed formulas with DHA had shorter-duration looks to visual stimuli at 12 months (evidence of maturer early cognition) compared with infants fed formula without DHA.135,150 In both studies higher visual acuity was found in the supplementation group early in infancy but was no longer present as assessed by the Teller Acuity Card procedure at 12 months of age.35,124 Higher intakes of oily fish during pregnancy have been related to higher stereo acuity in childhood.138 Reviews by both Wainwright52 and Colombo151 include arguments against a static interpretation of development and suggest the consideration of developmental systems theory152 to interpret behavioral data arising from studies that vary LC-PUFA status. The developmental systems perspective is transactional in nature: development occurs as a result of biologic and environmental bidirectional influences on the individual across time. Thus investigators need to consider environmental and metabolic factors that may interact with altered LC-PUFA status.

QUALITATIVE MOVEMENT AND EMOTIONAL DEVELOPMENT Hadders-Algra and her collaborators in the Netherlands153-157 published several reports on the effects of LC-PUFAs during pregnancy on motor milestones and quality of movement in infants and toddlers. A 2011 report linked better neurologic outcome at 5.5 years to higher umbilical cord red blood cell and plasma phospholipid DHA content.153 The LISAplus study conducted in Germany linked higher umbilical cord blood serum DHA, AA, and total LC-PUFA levels to parental assessment of less difficult behavior on the Strengths and Difficulties Questionnaire. In particular, fewer total difficulties, less hyperactivity/inattention, and fewer emotional symptoms at 10 years of age were found.158 In another study of problems from Germany, DHA in midpregnancy was associated with higher (favorable) scores on combined parent and teacher assessment of emotional and behavioral problems at 6 years of age, whereas AA was associated with lower (less favorable) scores.159 In contrast to these reports, a randomized trial conducted in Australia with DHA supplementation of 800 mg/day (and eicosapentaenoic acid 100 mg/day) during pregnancy found more total difficulties and more hyperactivity in the DHA-supplementation group compared with the placebo group.160

COGNITIVE DEVELOPMENT PROCESSES UNDERLYING COGNITIVE DEVELOPMENT

Two specific processes critically influence cognitive development and performance: those governing the acquisition of information (this includes speed of processing) and the retention of that information (memory).161 DHA is concentrated at the synapses162 and may act to improve synaptic efficiency and neuronal transmission speed. DHA has also been implicated in processes that are integral to the laying down of a memory trace, such as long-term potentiation in the hippocampus.163 Thus measurement of specific cognitive processes such as attention, processing speed, and memory is warranted in studies of the effects of DHA supplementation on the development of the child. We have

argued elsewhere that the integration of memory and attention underlies and drives the development of the higher-order cognitions known as executive functions.161 Executive functions include cognitive processes such as inhibitory control, problem solving, behavioral regulation, and planning/strategic behavior. It is likely that these developments are attributed to the development of the frontal lobes, which mature at a more protracted rate relative to the rest of the brain. Whereas such integrated cognition is initiated at the end of the first year, these abilities are not reliably evident until the early preschool period (e.g., 3 to 4 years of age). Brain frontal lobes accumulate significant amounts of DHA during their development.164 Moreover, dopamine is an important modulator of the executive functions, specifically working memory and attentional control.165 Dopamine concentration has been shown to decrease in the frontal area in DHA-depleted rats,73,74 and relative to DHA-adequate rats, the DHA-depleted rats do not do as well on executive function types of tasks31 (for a review, see Wainwright52). Moreover, the adverse effects of reduced brain DHA content during development are not remediated if brain DHA content is not remediated by weaning,75 suggesting long-term effects of poor perinatal DHA status. It seems reasonable to posit that the effects of DHA supplementation in infancy may also be manifest in the development of executive function. White matter quantity or quality may be another mechanism by which LC-PUFAs influence cognitive outcomes. White matter quality as assessed by diffusion tensor imaging is related to cognition,166,167 executive function and processing speed,168 verbal fluency,169 inhibitory control,170 and improvement of hyperactive/ impulsive symptoms.171 Martinez and colleagues172,173 were the first to identify the link between brain myelination and DHA when they provided children with generalized peroxisomal disorders (DHA synthesis requires normal peroxisome function) with DHA supplementation and found improved brain myelination and function. In 2014 Peters and colleagues174 associated brain white matter development from childhood to adulthood with a FADS haplotype that predicts higher levels of n-3 and n-6 LC-PUFAs in blood. As mentioned previously, white matter integrity has been related to early diet. Specifically, males who consumed human milk rather than formula had higher-quality white matter at 8 years of age and white matter quality was linked to performance on standardized tests of intellectual assessment and language fundamentals.114

AROUSAL Cheruku and colleagues175 reported an association between maternal plasma phospholipid DHA levels and brain maturation in newborn infants on the basis of differences in sleep patterns at birth. With maturation, there is an increase in quiet sleep, a decrease in active sleep, increased wakefulness, and a decrease in the transition from sleep to wake. These researchers noted inverse relationships between maternal DHA status and both active sleep and the ratio of active sleep to quiet sleep. They also found that maternal DHA status was associated with more time awake and less time in transition between sleep and wake in the infants. This observation is evidence of maturer function with higher DHA status and adds to the evidence that intrauterine exposure to DHA in the United States is inadequate for optimal brain development. In a subsequent small randomized study, Judge and colleagues176 provided pregnant women with a DHA-containing functional food (300 mg/day beginning at 24 weeks’ gestation) and found evidence of a benefit of maternal DHA supplementation for maturer infant sleep/wake states in the first 48 hours of life. The effect of maternal DHA on infant sleep/wake states signals a maturer autonomic nervous system. Increased maturity



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of the autonomic nervous system with maternal DHA supplementation was also demonstrated in another small study of prenatal DHA supplementation (600 mg/day beginning before 20 weeks and ending at birth). A higher fetal heart rate variability at 36 weeks’ gestation was found.177 The underlying effect of DHA on the autonomic nervous system could be due to effects of DHA supplementation on the endocannabinoid system as shown in a mouse model.178 However, other potential mechanisms of action for DHA in the brain exist.179-181 For example, the effects of DHA exposure on neurotransmitters73-75 may have longterm programming effects on brain function. More work in this area is needed to determine if the beneficial effects of supplementation in pregnancy are prolonged into infancy (i.e., if increased intrauterine DHA exposure has long-term effects on brain function).

LANGUAGE DEVELOPMENT The acquisition of vocabulary is a cognitive function, and most studies of language in preschool children measure vocabulary. As is commonly done, we separate studies of language development from those of more traditional cognitive outcomes, defined as the mental processes that occur within the organism between the presentation of a stimulus and the observation of a response. However, the development of vocabulary proceeds concomitantly with motor, cognitive, and social development, and therefore it is reasonable to posit a direct relation between language development and supplementation with DHA. Innis and colleagues137 found that several indicators of DHA status (plasma phospholipid DHA, red blood cell phosphatidylcholine DHA, and phosphatidylethanolamine DHA levels) in breast-fed infants were significantly correlated with the preservation of the ability to discriminate nonnative language at 9 months and with a parent-report measure of vocabulary comprehension and production at 14 months.182 O’Connor and colleagues119 found higher vocabulary comprehension at 14 months in preterm infants from English-speaking families who were fed formulas with DHA and AA than in those fed formulas without DHA and AA. Australian infants born at term and provided with a fish oil supplement with 250 mg DHA per day from birth to 6 months (consuming approximately twice as much DHA as infants consuming formula with 0.32% of total fatty acids as DHA) showed better language skills (total and later gestures) at 12 and 18 months on the MacArthur-Bates Communicative Development Inventory but they did not find differences between the groups in total words understood or spoken.183 There are three reports of apparent negative effects of DHA on early vocabulary: Lower scores on a parent-report language inventory were observed at 14 months of age in a DHAsupplementation group relative to a control group in the United States148 although this difference in vocabulary did not persist at 3 years of age when an age-appropriate standardized expressive language assessment (i.e., not parent report) was administered to the same children.184 Similarly, Lauritzen and colleagues185 found a lower language ability at 12 months of age in Danish breast-fed infants whose mothers had received DHA supplements compared with those who had not, but again these investigators did not find any difference between the groups when the children were 2 years old. Finally, in an extension of the DIAMOND study with the Dallas sample, Drover and colleagues186 found that infants who received supplementation with LC-PUFAs at 0.32% and 0.96% performed worse than controls on the third edition of the Peabody Picture Vocabulary Test (a standardized instrument for measuring receptive vocabulary) at 2 years of age. However, this age is slightly under the lowest age recommended for the use of the Peabody Picture Vocabulary Test, and the scores obtained for these children at 2 years of age (including the control group) were all at least one standard deviation below normal. It is thus likely that the use of this test at this age was

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not appropriate, a point further bolstered by the fact that these differences were no longer present when the test was repeated at 3.5 years of age. In summary, the nature of these negative findings may lie with issues surrounding the assessment of language comprehension and production (i.e., parent report and age appropriateness of the test used) or with antecedent differences in DHA status. In 2014 Mulder and colleagues79 reported results of language development between 14 and 18 months of age in children whose mothers were randomly assigned to a placebo or 400 mg DHA per day beginning at approximately 16 weeks of gestation until birth. They analyzed their results according to the risk for lower language development assuming there would be greater risk in the placebo group. DHA supplementation reduced the risk for lower language development assessed by words understood and produced and words understood and sentences produced on the MacArthur-Bates Communicative Development Inventory at 14 and 18 months of age, respectively, and expressive language on the third edition of the Bayley Scales of Infant Development at 18 months. There have been two reports of positive effects of higher perinatal DHA exposure on language functions in 5-year old children. A previous report from an observational study in the Seychelles, where fish consumption is very high, reached the conclusion that language in 5.5-year-old children was associated with maternal methylmercury exposure from seafood.187 The authors of that study later reanalyzed their data using models that included geometric means of maternal serum DHA and AA concentrations obtained early in the third trimester and at delivery and maternal prenatal hair methylmercury concentration. After this reanalysis, maternal DHA concentration predicted significantly higher total language score and verbal ability on the Preschool Language Scale-Revised Edition, whereas maternal AA concentration predicted lower scores on the test and on auditory comprehension at 5 years of age.188 On the Kaufman Brief Intelligence Test, higher maternal AA concentration predicted higher verbal knowledge.188 In a randomized controlled trial, all groups (control and LC-PUFA groups) performed similarly on the MacArthur-Bates Communicative Development Inventory at 18 months of age in the Kansas City DIAMOND trial cohort, but at 5 years of age the groups of children randomly assigned to LC-PUFA-supplemented formula in infancy (0.32%, 0.64%, or 0.96% DHA and 0.64% AA) scored significantly higher on the third edition of the Peabody Picture Vocabulary Test. At 6 years of age, the supplementation groups scored higher than the control group on the verbal IQ subscale of the third version of the Wechsler Preschool and Primary Scale of Intelligence.189 Children from this trial were invited to return for functional magnetic resonance imaging studies at approximately 9 years of age. LC-PUFA supplementation (0.32% and 0.64% DHA with 0.64% AA) in infancy resulted in an increased percentage of white matter; and the percentage of white matter was correlated with verbal IQ.190 Taken together, the results of all published trials indicate that higher LC-PUFA exposure in the perinatal period is a positive predictor of language function at school age.

VISUAL ATTENTION: RECOGNITION MEMORY AND ATTENTION Attention can be measured in infancy and is an early measure of cognition, because it relates to higher performance on more sophisticated measures of cognitive function at school age.191-193 Several studies in infants born preterm compared visual novelty preference (a test of visual recognition memory) and/or attention (look) duration in infants fed formulas with or without DHA or DHA and AA.119,135,150 Both novelty preference and shorter look duration in infancy are modestly correlated with higher cognitive function later in childhood (for a review, see Carlson

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and Neuringer59). Typically developing infants spend more time looking at a novel stimulus, and this characteristic has commonly been used to assess visual recognition memory early in life. In two randomized trials, the Fagan Infantest (Infantest Corporation, Cleveland, Ohio, USA) was used to measure visual novelty preference of very small preterm infants who averaged gestation of 28 weeks and a birth weight of approximately 1000 g. The program provided also measured looking duration. Whereas infants fed control and DHA-supplemented formulas had similar novelty preferences, infants who received DHA supplementation had a shorter look duration at 6, 9, and 12 months or at a corrected age of 12 months.135,150 These results are analogous to those reported in n-3-sufficient compared with n-3-deficient monkeys (i.e., higher DHA status correlated with shorter look duration).33 Both the non–human primate and the human studies suggest that higher brain DHA accumulation enhances the speed of visual processing or the ability of the infant to disengage from the stimulus or both. O’Connor and colleagues119 conducted a much larger multicenter trial and measured novelty preference and look duration with the Fagan Infantest in two groups of preterm infants whose diets were with supplemented with DHA and AA (fish/fungal and fish/egg triglyceride) and in a control group of infants whose diets were not supplemented with DHA and AA. All groups spent more time looking at the novel stimulus at 6 and 9 months of age as expected for these ages. No effect of supplementation on look duration was found. Compared with the two earlier reports, infants had longer gestations, less chronic lung disease, and higher birth weight, which might explain the lack of different outcomes for look duration. Look duration is a robust indicator of the development of attention, as it declines sharply across the first year of life. This decline was accelerated in infants born at term whose mothers had red blood cell phospholipid DHA levels higher than the median level of the sample relative to those whose mothers’ levels fell below the median.194 The difference in look duration disappeared by 8 months of age but reemerged as longer sustained attention at 12 and 18 months of age with the administration of more sophisticated tasks.194,195 Given that infants were not provided with DHA supplementation after birth and toddler DHA intake in the United States is very low,196 the data are consistent with the possibility that higher DHA accumulation during intrauterine life was responsible for maturer infant and toddler attention. Experimental studies that manipulate maternal DHA status during pregnancy are needed to test this hypothesis. Gould and colleagues197 reported no overall benefit of DHA supplementation during pregnancy (DOMInO trial) on childhood attention in Australian children at 2.3 years of age on single-object and distractibility tasks; however, on multiple-object attention tasks, toddlers who received DHA supplementation showed slightly fewer episodes of inattention. We made a similar observation in the Kansas City DIAMOND cohort, who were randomly assigned to DHA and AA supplementation after birth. At 9 months of age, infants who received DHA (0.32%, 0.64%, or 0.96%) supplementation and AA (0.64%) supplementation had higher proportions of sustained attention during looking compared with infants who were consuming the control formula.198 Between 2 and 6 years of age, this cohort of children was tested every 6 months on further specific measures of cognitive function, as detailed in the section on postnatal LCPUFA supplementation and cognitive function in childhood.

GLOBAL MEASURES OF DEVELOPMENT IN INFANTS AND YOUNG CHILDREN The Bayley Scales of Infant Development,199 developed in the United States, is now in its third version.200 Both the Mental Developmental Index (MDI) and Psychomotor Developmental Index (PDI) are standardized procedures that provide indices of

mental and motor age relative to group norms. Standardized tests tend to be familiar to pediatricians and interpreted with minimal ambiguity. As such, they have become most frequently used as outcome measures in studies of children receiving DHA supplementation. The Bayley Scales of Infant Development readily tests specific behavioral domains at a level of granularity that has been shown more recently to be influenced by LC-PUFA status, but the use of global assessments of development in such studies has yielded decidedly mixed results. Some studies have found that supplementation with DHA resulted in higher standardized scores,201-204 whereas other studies, including several larger and appropriately powered trials, have found no effect. There could be a number of reasons for these mixed results; for example, differences in samples, supplementation, and administration could confound the results. An important consideration, however, is that the primary purpose of standardized global assessments is to screen and identify infants and children at risk for developmental delays or disabilities. Such an approach may not be sensitive enough to always detect different rates of development in typically developing infants and children, or to detect effects that might be limited to a few cognitive/behavioral domains. Thus caution should be exercised when one is interpreting the results of interventions in which the primary outcomes are scores on global assessments. Because most studies of infants and toddlers rely on global measures of cognitive development, metaanalyses and systematic reviews are largely based on outcomes from the Bayley Scales of Infant Development. We strongly suggest that these metaanalyses be interpreted with caution.77 The Bayley Scales of Infant Development mental developmental index was higher in the combined groups that received DHA and AA supplementation than in the control group in the Dallas DIAMOND cohort205 but not in the Kansas City DIAMOND cohort.189 In 2011 Morales and colleagues190 found that LC-PUFA supply during pregnancy and lactation linked to the maternal FADS and elongation of very long chain fatty acids (ELOVL) genes were related to performance at 14 months of age on the second edition of the Bayley Scales of Infant Development. The effects of breast-feeding were modified by the child’s FADS and ELOVL genotype. In infants born preterm, Sabel and colleagues112 observed a positive relationship between performance on the second edition of the Bayley Scales of Infant Development and infant plasma DHA and AA concentrations at a corrected age of 1 month. Infants had been fed their mother’s milk, with variable DHA and AA concentrations. They were evaluated at several ages in infancy and again at 18 months. Thus the global assessments may have utility in studies of at-risk children such as those with preterm histories or studies in the hypothesis-building stages such as the current state of the genetic work.

TARGETED MEASURES OF COGNITIVE DEVELOPMENT IN INFANTS AND YOUNG CHILDREN Researchers who have used targeted measures of cognitive development in infants and very young children more consistently find benefits than do researchers who have used global measures. As noted previously, infants fed formula supplemented with DHA or DHA and AA are better able to detect novelty,119 show faster visual processing,135,150,206 and have better problem solving207,208 compared with those fed control formula without LC-PUFAs. As previously mentioned, infants whose mothers had DHA levels above the sample median at the time of their births had enhanced information processing performance, as well as maturer orienting and attentional abilities.194

PRENATAL LONG-CHAIN POLYUNSATURATED FATTY ACIDS AND COGNITIVE OUTCOMES IN CHILDHOOD At the time of the third edition of this book, there were a few observational reports of cognitive function in children in



Chapter 38 — Long-Chain Polyunsaturated Fatty Acids in the Developing Central Nervous System

relation to maternal DHA status and a couple of reports from randomized clinical trials that provided DHA or AA during the perinatal period. Since publication of the third edition of this book, Gustafsson and colleagues209 have reported that DHA levels in colostrum were significantly related to IQ at 6.5 years of age. As noted in the section entitled “Language Development,” higher maternal DHA content during pregnancy in the Seychelles was linked to higher language scores at 5 years of age on a test of preschool language development.188 Another study from the Seychelles found beneficial effects of maternal n-3 LC-PUFAs but not n-6 LC-PUFAs on the second edition of the Bayley Scales of Infant Development psychomotor developmental index at 9 months of age.210 Movement quality at 7 years of age was associated with higher umbilical cord plasma DHA content (signifying higher intrauterine DHA exposure).211 Both maternal DHA and AA during pregnancy had a significant positive effect on IQ at 8 years of age in another large cohort (n=2839).212 Analogous to work done in the Seychelles, the Jacobsons and their colleagues sought to untangle the adverse effects of environmental pollutants from the possible beneficial effects of n-3 LC-PUFAs on cognitive function in a high-fish-consuming population in Arctic Quebec. In children at a mean age of 11.3 years, they found shorter brain F400 latency and enhanced amplitude (both suggesting greater brain maturation), as well as higher performance on a task assessing memory in relation to the DHA level measured at birth in umbilical cord blood.213 In another study, higher DHA intake during pregnancy was linked to performance on a task measuring search for a novel object at 22 months of age.214 In yet another study, researchers assessed neurologic development at 4 and 5.5 years of age in children of pregnant women enrolled in Spain, Germany, and Hungary. Similarly to the findings reported by Mulder and colleagues,79 the odds of children with optimal neurologic development increased with each unit increase in umbilical cord blood, maternal plasma, and maternal erythrocyte phospholipid DHA content at birth.153 Several randomized clinical trials that provided DHA or a placebo during pregnancy have now reported on cognitive function of the offspring. In an Australian trial by Dunstan and colleagues,215 there was no effect on hand-eye coordination in the supplementation group at 2.5 years of age, but hand-eye coordination scores were significantly related to n-3 LC-PUFA levels in umbilical cord blood erythrocytes. As mentioned previously, Helland and colleagues216 found higher IQ on a standardized test at 4 years of age in Norwegian children whose mothers received a very large fish oil supplement during pregnancy and the first several months of lactation. At 7 years of age, children of women assigned to placebo did not differ in cognitive assessment from those assigned to fish oil during pregnancy, but maternal DHA during pregnancy was associated with higher scores on the Kaufman Assessment Battery for Children sequential processing index.217 No effect of LC-PUFA supplementation was found on the outcomes measured during infancy. Maternal DHA and eicosapentaenoic acid supplementation during pregnancy did not affect working memory at 2.3 years in the Australian DOMInO trial.197 At 4 years of age, the DHAsupplementation group in that trial still showed no benefit, although the group members did score significantly higher than children of mothers who received no supplementation on two subscales of the Behavior Rating Inventory of Executive FunctionPreschool.160 Campoy and colleagues218 reported that fish oil supplementation during pregnancy did not affect Kaufman Assessment Battery for Children scores, although higher maternal erythrocyte DHA content at birth was associated with scores above the 50th percentile on the Mental Processing Composite Score.

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POSTNATAL LONG-CHAIN POLYUNSATURATED FATTY ACIDS AND COGNITIVE OUTCOMES IN CHILDHOOD The Southampton Women’s Survey Study Group compared fullscale and verbal IQ of 4-year-old children fed formulas with or without LC-PUFAs during infancy. Whereas both full-scale and verbal IQ were higher in the LC-PUFA formula–fed group, the investigators did not find any effect of LC-PUFA-supplemented formula when they controlled for maternal IQ and education in this nonrandomized study.219 Jensen and colleagues220 randomly assigned US women to consume 200 mg of DHA per day from a single-cell oil during lactation. The toddlers of the women who received supplements had higher scores on a standardized test of motor function at 30 months of age220 and longer sustained attention at 5 years of age.221 The average milk DHA content was 0.35% of total fatty acids (equivalent to that in most US formulas).220 Three recent reports provide results for older children randomly exposed to LC-PUFA-supplemented formula for a short period of time (2 to 4 months) after birth. Willatts and colleagues222 reported that 6-year-old children who received supplementation with formula containing DHA and AA for the first 4 months of life showed faster information processing but there was no overall effect on IQ or attention control. The Groningen LC-PUFA study provided a supplemented formula for only 2 months after term birth and found an interaction between LC-PUFA supplementation and maternal smoking with regard to child IQ at 9 years of age; specifically, children of women who smoked during pregnancy had significantly higher verbal IQ and learning memory scores on the Wechsler Abbreviated Scale of Intelligence and the Children’s Memory Scale, respectively, if they received LC-PUFAs.223 On the other hand, the control group performed better than the LC-PUFA group on verbal IQ and verbal memory tests in children of women who did not smoke during pregnancy.223 No effect of early LC-PUFA supplementation was found on the Neurological Optimality Score at 9 years of age.224 Cognitive performance of 7-year-old Danish children was not influenced by maternal fish oil consumption during the first 4 months of lactation, however, the mean maternal n-3 LC-PUFA intake in the control group was 260 mg/day,225 approximately 5 times that of most US adult females. The fish-oil-supplementation group had a mean n-3 LC-PUFA intake of 1.59 g/day. There was a trend for lower prosocial score in the supplementation group (a potential adverse effect of maternal fish oil consumption), which post hoc analysis demonstrated to be related to a higher prosocial score in males whose mothers were in the control formula group compared with the scores of children whose mothers were in the LC-PUFA group. These authors suggest the post hoc result should be regarded with caution because the study was not designed to look at sex effects. Cognitive function has been evaluated in both Dallas and Kansas City cohorts of the DIAMOND trial. As mentioned earlier, the DIAMOND study was a randomized controlled DHA doseresponse study of DHA- and AA-supplemented infant formula with infants provided with the study formulas from birth to 12 months of age. The DIAMOND cohort studied in Kansas City was evaluated for attention and memory in infancy and on ageappropriate tests of cognitive function every 6 months beginning at 18 months and ending at 6 years of age. At preschool age, the children who received LC-PUFA supplementation during infancy scored significantly higher on tests of inhibitory control (Stroop, Dimensional Change Card Sort) and on tests of verbal IQ.189 Unlike the Dallas cohort, no benefit of LC-PUFAs was observed at 18 months of age on the MacArthur-Bates Communicative Development Inventory or the second edition of the Bayley Scales of Infant Development189 when they were analyzed by intervention group. However, Drover and colleagues205

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evaluated performance on the second edition of the Bayley Scales of Infant Development in toddlers and reported significantly higher performance in the combined LC-PUFA-supplementation groups with DHA intake ranging from 0.32% to 0.96% of total fatty acids (see “Global Measures of Development in Infants and Young Children”). Also in this trial, more maturer brain electrophysiology was found in the children at 5.5 years of age on a go–no go task requiring them to make or inhibit a button press when a fish or shark, respectively, appeared on a screen.226 During the same test, only the group receiving a 1 : 1 ratio of DHA and AA (0.64% DHA and AA) displayed a second N170 peak, found in adults but not infants, and believed to reflect figural processing by the lateral temporal cortices; that is, evidence of maturer brain function. About half of the children returned for functional magnetic resonance imaging and magnetoencephalography at approximately 9 years of age, and these results continue to show positive effects of LCPUFA; however, the results are only now being prepared for review. When we consider all the research together, it is apparent that LC-PUFAs have effects on specific cognitive abilities and, by extension, the neural substrates that subserve them. The tests of specific cognitive abilities are more difficult to administer and interpret. It will be important for nutritionists, biochemists, and developmental psychologists to collaborate in future explorations of the utility of LC-PUFAs in improving the cognitive abilities of children. Through these transdiscipline collaborations, the true nature of the relation between LC-PUFAs and the brain will become evident.

SUMMARY In 2002 DHA and AA began to be added to formulas in the United States. The last randomized trial of LC-PUFA-supplemented formula began in 2003 and was the only dose-response study of LC-PUFAs conducted.46 The Kansas City cohort from that trial has been studied out to 10 years of age, and the results demonstrate clear benefits of LC-PUFA supplementation, ranging from longer sustained attention and better memory in infancy to higher verbal IQ and ability to inhibit behavior at school age. These findings are supported by brain electrophysiology findings at 5.5 years (evoked response potentials) and magnetoencephalography and functional magnetic resonance imaging findings at 9 to 10 years (higher density white matter; and a higher percentage of white matter compared with gray matter that correlates with verbal IQ). Whereas this is one of the more intensely and comprehensively evaluated cohorts of children randomized to variable levels of LC-PUFAs in the perinatal period, there are a number of quite recent reports of cognitive outcomes at school age and beyond from cohorts exposed perinatally (prenatally or postnatally) to DHA or DHA and AA. At the time of the third edition of this book, results in children exposed to higher DHA levels during the perinatal periods were very limited; available reports showed higher IQ at 4 years of age216 and longer sustained attention at 5 years of age.221 These two early studies encouraged other investigators to follow cohorts of children into childhood, because they provided the first evidence that perinatal exposure to LC-PUFAs could program the developing brain with long-term benefit to cognition. It is now clear that LC-PUFAs are needed for optimal fetal and neonatal development, some samples received inadequate supplementation in the perinatal period, and the presence of LC-PUFAs in the perinatal period appears to confer a long-term benefit (i.e., programs later brain function). Very recent evidence suggests that changes in the ratio of white matter to gray matter and white matter quality long after LC-PUFA exposure are linked to this programming. Animal studies have already shown

that DHA is a factor in neuronal development. In addition, there are other possible mechanisms through which LC-PUFAs program the developing brain and influence later brain outcomes. For example, animal studies have shown programming of neurotransmitter systems occurs very early in development in relation to DHA supply. Although the importance of DHA in infant development is becoming increasingly obvious from human and animal work, the optimal and maximum levels of DHA intake for pregnant women and infants have not yet been determined. Likewise, the optimal balance of DHA and AA is not known, and this balance may be different during pregnancy compared with postnatally. Progress in these areas is to be expected, because a number of large trials are currently ongoing around the world. However, it is clear that these studies are being conducted at the same time as DHA intake from supplements, supplemented food, and formula may be changing the background DHA exposure of women, infants, and children. Variable DHA exposure in control groups will be a potential confounder in new studies of DHA supplementation. Studies of infant behavior will need to control for maternal prenatal and background diet postnatal LC-PUFA intake and/or use some biochemical measure of LC-PUFA status such as red blood cell or plasma phospholipid concentrations. In addition, evidence of a confounding effect of maternal and offspring genetics is amassing. The presence of minor alleles in the FADS gene complex may predispose an individual to a higher need for exogenous DHA, as the enzymes for the metabolism of the precursors may be less functional. Researchers must consider the genetic makeup of the mothers and babies, as well as background diet, to fully elucidate the effects of LC-PUFAs on human development. Complete reference list is available at www.ExpertConsult.com.

REFERENCES 1. O’Brien JS, Fillerup DL, Mead JF: Quantification and fatty acid and fatty aldehyde composition of ethanolamine, choline, and serine glycerophosphatides in human cerebral grey and white matter. J Lipid Res 5(3):329–338, 1964. 2. Anderson RE, Maude MB, Zimmerman W: Lipids of ocular tissues—X. Lipid composition of subcellular fractions of bovine retina. Vision Res 15:1087– 1090, 1975. 3. Clandinin MT, Chappell JE, Leong S, et  al: Intrauterine fatty acid accretion rates in human brain: implications for fatty acid requirements. Early Hum Dev 4(2):121–129, 1980. 4. Martinez M: Developmental profiles of polyunsaturated fatty acids in the brain of normal infants and patients with peroxisomal diseases: severe deficiency of docosahexaenoic acid in Zellweger’s and pseudo-Zellweger’s syndromes. World Rev Nutr Diet 66:87–102, 1991. 5. Ruyle M, Connor WE, Anderson GJ, Lowensohn RI: Placental transfer of essential fatty acids in humans: venous-arterial difference for docosahexaenoic acid in fetal umbilical erythrocytes. Proc Natl Acad Sci U S A 87(20):7902–7906, 1990. 6. Dutta-Roy AK: Transport mechanisms for long-chain polyunsaturated fatty acids in the human placenta. Am J Clin Nutr 71(1 Suppl):315s–322s, 2000. 8. Putnam JC, Carlson SE, DeVoe PW, Barness LA: The effect of variations in dietary fatty acids on the fatty acid composition of erythrocyte phosphatidylcholine and phosphatidylethanolamine in human infants. Am J Clin Nutr 36(1):106–114, 1982. 13. Farquharson J, Cockburn F, Patrick WA, et al: Infant cerebral cortex phospholipid fatty-acid composition and diet. Lancet 340(8823):810–813, 1992. 14. Makrides M, Neumann MA, Byard RW, et al: Fatty acid composition of brain, retina, and erythrocytes in breast- and formula-fed infants. Am J Clin Nutr 60(2):189–194, 1994. 17. Carnielli VP, Simonato M, Verlato G, et al: Synthesis of long-chain polyunsaturated fatty acids in preterm newborns fed formula with long-chain polyunsaturated fatty acids. Am J Clin Nutr 86(5):1323–1330, 2007. 21. Benolken RM, Anderson RE, Wheeler TG: Membrane fatty acids associated with the electrical response in visual excitation. Science 182(4118):1253– 1254, 1973. 22. Wheeler TG, Benolken RM, Anderson RE: Visual membranes: specificity of fatty acid precursors for the electrical response to illumination. Science 188(4195):1312–1314, 1975. 23. Weisinger HS, Armitage JA, Jeffrey BG, et al: Retinal sensitivity loss in thirdgeneration n-3 PUFA-deficient rats. Lipids 37(8):759–765, 2002.



Chapter 38 — Long-Chain Polyunsaturated Fatty Acids in the Developing Central Nervous System 24. Neuringer M, Connor WE, Van Petten C, Barstad L: Dietary omega-3 fatty acid deficiency and visual loss in infant rhesus monkeys. J Clin Invest 73(1):272– 276, 1984. 33. Reisbick S, Neuringer M, Gohl E, et  al: Visual attention in infant monkeys: effects of dietary fatty acids and age. Dev Psychol 33(3):387–395, 1997. 35. Carlson SE, Werkman SH, Rhodes PG, Tolley EA: Visual-acuity development in healthy preterm infants: effect of marine-oil supplementation. Am J Clin Nutr 58(1):35–42, 1993. 36. Birch EE, Birch DG, Hoffman DR, Uauy R: Dietary essential fatty acid supply and visual acuity development. Invest Ophthalmol Vis Sci 33(11):3242–3253, 1992. 37. Birch DG, Birch EE, Hoffman DR, Uauy RD: Retinal development in very-lowbirth-weight infants fed diets differing in omega-3 fatty acids. Invest Ophthalmol Vis Sci 33(8):2365–2376, 1992. 46. Birch EE, Carlson SE, Hoffman DR, et al: The DIAMOND (DHA Intake And Measurement Of Neural Development) study: a double-masked, randomized controlled clinical trial of the maturation of infant visual acuity as a function of the dietary level of docosahexaenoic acid. Am J Clin Nutr 91(4):848–859, 2010. 72. Hibbeln JR, Ferguson TA, Blasbalg TL: Omega-3 fatty acid deficiencies in neurodevelopment, aggression and autonomic dysregulation: opportunities for intervention. Int Rev Psychiatry 18(2):107–118, 2006. 73. Delion S, Chalon S, Hérault J, et al: Chronic dietary alpha-linolenic acid deficiency alters dopaminergic and serotoninergic neurotransmission in rats. J Nutr 124(12):2466–2476, 1994. 74. Delion S, Chalon S, Guilloteau D, et al: alpha-Linolenic acid dietary deficiency alters age-related changes of dopaminergic and serotoninergic neurotransmission in the rat frontal cortex. J Neurochem 66(4):1582–1591, 1996. 76. Papanikolaou Y, Brooks J, Reider C, Fulgoni VL, 3rd: U.S. adults are not meeting recommended levels for fish and omega-3 fatty acid intake: results of an analysis using observational data from NHANES 2003-2008. Nutr J 13:31, 2014. 85. Zeijdner EE, van Houwelingen AC, Kester AD, Hornstra G: Essential fatty acid status in plasma phospholipids of mother and neonate after multiple pregnancy. Prostaglandins Leukot Essent Fatty Acids 56(5):395–401, 1997. 86. Haggarty P: Fatty acid supply to the human fetus. Annu Rev Nutr 30:237–255, 2010. 87. Kuipers RS, Luxwolda MF, Offringa PJ, et  al: Gestational age dependent changes of the fetal brain, liver and adipose tissue fatty acid compositions in a population with high fish intakes. Prostaglandins Leukot Essent Fatty Acids 86(4–5):189–199, 2012. 92. Innis SM: Human milk and formula fatty acids. J Pediatr 120(4 Pt 2):S56–S61, 1992. 93. Xie L, Innis SM: Genetic variants of the FADS1 FADS2 gene cluster are associated with altered (n-6) and (n-3) essential fatty acids in plasma and erythrocyte phospholipids in women during pregnancy and in breast milk during lactation. J Nutr 138(11):2222–2228, 2008. 94. Koletzko B, Lattka E, Zeilinger S, et al: Genetic variants of the fatty acid desaturase gene cluster predict amounts of red blood cell docosahexaenoic and other polyunsaturated fatty acids in pregnant women: findings from the Avon Longitudinal Study of Parents and Children. Am J Clin Nutr 93(1):211– 219, 2011.

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100. Henderson RA, Jensen RG, Lammi-Keefe CJ, et al: Effect of fish oil on the fatty acid composition of human milk and maternal and infant erythrocytes. Lipids 27(11):863–869, 1992. 103. Koletzko B, Thiel I, Abiodun PO: The fatty acid composition of human milk in Europe and Africa. J Pediatr 120(4 Pt 2):S62–S70, 1992. 104. Molto-Puigmarti C, Plat J, Mensink RP, et al: FADS1 FADS2 gene variants modify the association between fish intake and the docosahexaenoic acid proportions in human milk. Am J Clin Nutr 91(5):1368–1376, 2010. 105. Cheatham CL: FADS1/FADS2 single nucleotide polymorphisms as markers for fatty acid status of human milk. FASEB J 26:624–626, 2012. 110. Ntoumani E, Strandvik B, Sabel KG: Nervonic acid is much lower in donor milk than in milk from mothers delivering premature infants—of neglected importance? Prostaglandins Leukot Essent Fatty Acids 89(4):241–244, 2013. 113. Lassek WD, Gaulin SJ: Linoleic and docosahexaenoic acids in human milk have opposite relationships with cognitive test performance in a sample of 28 countries. Prostaglandins Leukot Essent Fatty Acids 91(5):195–201, 2014. 141. Gustafson KM, Colombo J, Carlson SE, et al: A randomized controlled trial of DHA supplementation during pregnancy: visual acuity development. 172. Martinez M, Vásquez E, Garcia-Silva MT, et al: Therapeutic effects of docosahexaenoic acid ethyl ester in patients with generalized peroxisomal disorders. Am J Clin Nutr 71(1 Suppl):376s–385s, 2000. 176. Judge MP, Cong X, Harel O, et al: Maternal consumption of a DHA-containing functional food benefits infant sleep patterning: an early neurodevelopmental measure. Early Hum Dev 88(7):531–537, 2012. 179. Kim HY, Spector AA, Xiong ZM: A synaptogenic amide Ndocosahexaenoylethanolamide promotes hippocampal development. Prostaglandins Other Lipid Mediat 96(1–4):114–120, 2011. 180. Kim HY, Moon HS, Cao D, et al: N-Docosahexaenoylethanolamide promotes development of hippocampal neurons. Biochem J 435(2):327–336, 2011. 182. Innis SM: Perinatal biochemistry and physiology of long-chain polyunsaturated fatty acids. J Pediatr 143(4 Suppl):S1–S8, 2003. 188. Strain JJ, et al: Maternal PUFA status but not prenatal methylmercury exposure is associated with children’s language functions at age five years in the Seychelles. J Nutr 142(11):1943–1949, 2012. 197. Gould JF, Makrides M, Colombo J, Smithers LG: Randomized controlled trial of maternal omega-3 long-chain PUFA supplementation during pregnancy and early childhood development of attention, working memory, and inhibitory control. Am J Clin Nutr 99(4):851–859, 2014. 204. Cohen JT, Bellinger DC, Connor WE, Shaywitz BA: A quantitative analysis of prenatal intake of n-3 polyunsaturated fatty acids and cognitive development. Am J Prev Med 29(4):366–374, 2005. 215. Dunstan JA, Simmer K, Dixon G, Prescott SL: Cognitive assessment of children at age 2(1/2) years after maternal fish oil supplementation in pregnancy: a randomised controlled trial. Arch Dis Child Fetal Neonatal Ed 93(1):F45– F50, 2008. 219. Gale CR, Marriott LD, Martyn CN, et al: Breastfeeding, the use of docosahexaenoic acid-fortified formulas in infancy and neuropsychological function in childhood. Arch Dis Child 95(3):174–179, 2010. 226. Liao KMB, McCandliss BD, Carlson SE, et al: Event-related potential differences in children supplemented with long-chain polyunsaturated fatty acids during infancy. Devel Sci in press.



Chapter 38 — Long-Chain Polyunsaturated Fatty Acids in the Developing Central Nervous System

REFERENCES 1. O’Brien JS, Fillerup DL, Mead JF: Quantification and fatty acid and fatty aldehyde composition of ethanolamine, choline, and serine glycerophosphatides in human cerebral grey and white matter. J Lipid Res 5(3):329–338, 1964. 2. Anderson RE, Maude MB, Zimmerman W: Lipids of ocular tissues—X. Lipid composition of subcellular fractions of bovine retina. Vision Res 15:1087– 1090, 1975. 3. Clandinin MT, Chappell JE, Leong S, et al: Intrauterine fatty acid accretion rates in human brain: implications for fatty acid requirements. Early Hum Dev 4(2):121–129, 1980. 4. Martinez M: Developmental profiles of polyunsaturated fatty acids in the brain of normal infants and patients with peroxisomal diseases: severe deficiency of docosahexaenoic acid in Zellweger’s and pseudo-Zellweger’s syndromes. World Rev Nutr Diet 66:87–102, 1991. 5. Ruyle M, Connor WE, Anderson GJ, Lowensohn RI: Placental transfer of essential fatty acids in humans: venous-arterial difference for docosahexaenoic acid in fetal umbilical erythrocytes. Proc Natl Acad Sci U S A 87(20):7902–7906, 1990. 6. Dutta-Roy AK: Transport mechanisms for long-chain polyunsaturated fatty acids in the human placenta. Am J Clin Nutr 71(1 Suppl):315s–322s, 2000. 7. Sanders TA, Naismith DJ: A comparison of the influence of breast-feeding and bottle-feeding on the fatty acid composition of the erythrocytes. Br J Nutr 41(3):619–623, 1979. 8. Putnam JC, Carlson SE, DeVoe PW, Barness LA: The effect of variations in dietary fatty acids on the fatty acid composition of erythrocyte phosphatidylcholine and phosphatidylethanolamine in human infants. Am J Clin Nutr 36(1):106–114, 1982. 9. Demmelmair H, von Schenck U, Behrendt E, et al: Estimation of arachidonic acid synthesis in full term neonates using natural variation of 13C content. J Pediatr Gastroenterol Nutr 21(1):31–36, 1995. 10. Carnielli VP, Wattimena DJ, Luijendijk IH, et al: The very low birth weight premature infant is capable of synthesizing arachidonic and docosahexaenoic acids from linoleic and linolenic acids. Pediatr Res 40(1):169–174, 1996. 11. Salem N, Jr, Wegher B, Mena P, Uauy R: Arachidonic and docosahexaenoic acids are biosynthesized from their 18-carbon precursors in human infants. Proc Natl Acad Sci U S A 93(1):49–54, 1996. 12. Sauerwald TU, Hachey DL, Jensen CL, et al: Intermediates in endogenous synthesis of C22:6 omega 3 and C20:4 omega 6 by term and preterm infants. Pediatr Res 41(2):183–187, 1997. 13. Farquharson J, Cockburn F, Patrick WA, et al: Infant cerebral cortex phospholipid fatty-acid composition and diet. Lancet 340(8823):810–813, 1992. 14. Makrides M, Neumann MA, Byard RW, et al: Fatty acid composition of brain, retina, and erythrocytes in breast- and formula-fed infants. Am J Clin Nutr 60(2):189–194, 1994. 15. Farquharson J, Jamieson EC, Abbasi KA, et al: Effect of diet on the fatty acid composition of the major phospholipids of infant cerebral cortex. Arch Dis Child 72(3):198–203, 1995. 16. Clandinin MT, Chappell JE, van Aerde JE: Requirements of newborn infants for long chain polyunsaturated fatty acids. Acta Paediatr Scand Suppl 351:63–71, 1989. 17. Carnielli VP, Simonato M, Verlato G, et al: Synthesis of long-chain polyunsaturated fatty acids in preterm newborns fed formula with long-chain polyunsaturated fatty acids. Am J Clin Nutr 86(5):1323–1330, 2007. 18. Harsløf LB, Larsen LH, Ritz C, et al: FADS genotype and diet are important determinants of DHA status: a cross-sectional study in Danish infants. Am J Clin Nutr 97(6):1403–1410, 2013. 19. Gibson RA, Neumann MA, Lien EL, et al: Docosahexaenoic acid synthesis from alpha-linolenic acid is inhibited by diets high in polyunsaturated fatty acids. Prostaglandins Leukot Essent Fatty Acids 88(1):139–146, 2013. 20. Sauerwald UC, Fink MM, Demmelmair H, et al: Effect of different levels of docosahexaenoic acid supply on fatty acid status and linoleic and alphalinolenic acid conversion in preterm infants. J Pediatr Gastroenterol Nutr 54(3):353–363, 2012. 21. Benolken RM, Anderson RE, Wheeler TG: Membrane fatty acids associated with the electrical response in visual excitation. Science 182(4118):1253– 1254, 1973. 22. Wheeler TG, Benolken RM, Anderson RE: Visual membranes: specificity of fatty acid precursors for the electrical response to illumination. Science 188(4195):1312–1314, 1975. 23. Weisinger HS, Armitage JA, Jeffrey BG, et al: Retinal sensitivity loss in thirdgeneration n-3 PUFA-deficient rats. Lipids 37(8):759–765, 2002. 24. Neuringer M, Connor WE, Van Petten C, Barstad L: Dietary omega-3 fatty acid deficiency and visual loss in infant rhesus monkeys. J Clin Invest 73(1):272– 276, 1984. 25. Lamptey MS, Walker BL: A possible essential role for dietary linolenic acid in the development of the young rat. J Nutr 106(1):86–93, 1976. 26. Yamamoto N, Saitoh M, Moriuchi A, et al: Effect of dietary alpha-linolenate/ linoleate balance on brain lipid compositions and learning ability of rats. J Lipid Res 28(2):144–151, 1987. 27. Yamamoto N, Hashimoto A, Takemoto Y, et al: Effect of the dietary alphalinolenate/linoleate balance on lipid compositions and learning ability of rats. II. Discrimination process, extinction process, and glycolipid compositions. J Lipid Res 29(8):1013–1021, 1988.

389.e1

28. Garcia-Calatayud S, Redondo C, Martin E, et al: Brain docosahexaenoic acid status and learning in young rats submitted to dietary long-chain polyunsaturated fatty acid deficiency and supplementation limited to lactation. Pediatr Res 57(5 Pt 1):719–723, 2005. 29. Bourre JM, Francois M, Youyou A, et al: The effects of dietary alpha-linolenic acid on the composition of nerve membranes, enzymatic activity, amplitude of electrophysiological parameters, resistance to poisons and performance of learning tasks in rats. J Nutr 119(12):1880–1892, 1989. 30. Lim SY, Hoshiba J, Moriguchi T, Salem N, Jr: N-3 fatty acid deficiency induced by a modified artificial rearing method leads to poorer performance in spatial learning tasks. Pediatr Res 58(4):741–748, 2005. 31. Takeuchi T, Fukumoto Y, Harada E: Influence of a dietary n-3 fatty acid deficiency on the cerebral catecholamine contents, EEG and learning ability in rat. Behav Brain Res 131(1–2):193–203, 2002. 32. Wainwright PE, Huang YS, Coscina DV, et al: Brain and behavioral effects of dietary n-3 deficiency in mice: a three generational study. Dev Psychobiol 27(7):467–487, 1994. 33. Reisbick S, Neuringer M, Gohl E, et al: Visual attention in infant monkeys: effects of dietary fatty acids and age. Dev Psychol 33(3):387–395, 1997. 34. Galli C, White HB, Jr, Paoletti R: Lipid alterations and their reversion in the central nervous system of growing rats deficient in essential fatty acids. Lipids 6(6):378–387, 1971. 35. Carlson SE, Werkman SH, Rhodes PG, Tolley EA: Visual-acuity development in healthy preterm infants: effect of marine-oil supplementation. Am J Clin Nutr 58(1):35–42, 1993. 36. Birch EE, Birch DG, Hoffman DR, Uauy R: Dietary essential fatty acid supply and visual acuity development. Invest Ophthalmol Vis Sci 33(11):3242–3253, 1992. 37. Birch DG, Birch EE, Hoffman DR, Uauy RD: Retinal development in very-lowbirth-weight infants fed diets differing in omega-3 fatty acids. Invest Ophthalmol Vis Sci 33(8):2365–2376, 1992. 38. McCann JC, Ames BN: Is docosahexaenoic acid, an n-3 long-chain polyunsaturated fatty acid, required for development of normal brain function? An overview of evidence from cognitive and behavioral tests in humans and animals. Am J Clin Nutr 82(2):281–295, 2005. 39. Lewin GA, Schachter HM, Yuen D, et al: Effects of omega-3 fatty acids on child and maternal health. Evid Rep Technol Assess (Summ) 118:1–11, 2005. 40. Simmer K, Patole SK, Rao SC: Long-chain polyunsaturated fatty acid supplementation in infants born at term. Cochrane Database Syst Rev 1:CD000376, 2008. 41. Simmer K, Schulzke SM, Patole S: Long-chain polyunsaturated fatty acid supplementation in preterm infants. Cochrane Database Syst Rev 1:CD000375, 2008. 42. Simmer K, Patole SK, Rao SC: Long-chain polyunsaturated fatty acid supplementation in infants born at term. Cochrane Database Syst Rev 12:CD000376, 2011. 43. Innis SM: Impact of maternal diet on human milk composition and neurological development of infants. Am J Clin Nutr 99(3):734s–741s, 2014. 44. Brenna JT, Carlson SE: Docosahexaenoic acid and human brain development: evidence that a dietary supply is needed for optimal development. J Hum Evol 77:99–106, 2014. 45. Rogers LK, Valentine CJ, Keim SA: DHA supplementation: current implications in pregnancy and childhood. Pharmacol Res 70(1):13–19, 2013. 46. Birch EE, Carlson SE, Hoffman DR, et al: The DIAMOND (DHA Intake And Measurement Of Neural Development) study: a double-masked, randomized controlled clinical trial of the maturation of infant visual acuity as a function of the dietary level of docosahexaenoic acid. Am J Clin Nutr 91(4):848–859, 2010. 47. EFSA Panel on Dietetic Products, Nutrition and Allergies: Scientific opinion on the essential composition of infant and follow-on formula. Food safety association (EFSA) J 12:3760, 2014. 48. Koletzko B, Carlson SE, van Goudoever JB: Should infant formula provide both omega-3 DHA and omega-6 arachidonic acid? Ann Nutr Metab 66(2– 3):137–138, 2015. 49. Sheppard KW, Cheatham CL: Omega-6 to omega-3 fatty acid ratio and higherorder cognitive functions in 7- to 9-y-olds: a cross-sectional study. Am J Clin Nutr 98(3):659–667, 2013. 50. Hoffman DR, Birch EE, Birch DG, Uauy RD: Effects of supplementation with omega 3 long-chain polyunsaturated fatty acids on retinal and cortical development in premature infants. Am J Clin Nutr 57(5 Suppl):807s–812s, 1993. 51. Neuringer M, Connor WE, Lin DS, et al: Biochemical and functional effects of prenatal and postnatal omega 3 fatty acid deficiency on retina and brain in rhesus monkeys. Proc Natl Acad Sci U S A 83(11):4021–4025, 1986. 52. Wainwright PE: Dietary essential fatty acids and brain function: a developmental perspective on mechanisms. Proc Nutr Soc 61(1):61–69, 2002. 53. Wainwright PE: Lipids and behavior: the evidence from animal models, Columbus, OH, USA, 1993, Ross Laboratories. 54. Enslen M, Nouvelot A, Milon H: Effects of n-3 polyunsaturated fatty acid deficiency during development in the rat: future effects. In Lands WEM, editor: Proceedings of the AOCS short course on polyunsaturated fatty acids and eicosanoids, Biloxi, MS, 1987, AOCS Press, p 495. Urbana, Ill, 1987, AOCS Press. 55. Leat WM, Curtis R, Millichamp NJ, Cox RW: Retinal function in rats and guinea-pigs reared on diets low in essential fatty acids and supplemented with linoleic or linolenic acids. Ann Nutr Metab 30(3):166–174, 1986.

389.e2 SECTION VI — Lipid Metabolism 56. Yehuda S, Carasso RL: Modulation of learning, pain thresholds, and thermoregulation in the rat by preparations of free purified alpha-linolenic and linoleic acids: determination of the optimal omega 3-to-omega 6 ratio. Proc Natl Acad Sci U S A 90(21):10345–10349, 1993. 57. Colombo J, Mitchell DW, Coldren JT, Freeseman LJ: Individual differences in infant visual attention: are short lookers faster processors or feature processors? Child Dev 62(6):1247–1257, 1991. 58. Johnson MH, Posner MI, Rothbart MK: Components of visual orienting in early infancy: contingency learning, anticipatory looking, and disengaging. J Cogn Neurosci 3(4):335–344, 1991. 59. Carlson SE, Neuringer M: Polyunsaturated fatty acid status and neurodevelopment: a summary and critical analysis of the literature. Lipids 34(2):171–178, 1999. 60. Frances H, Monier C, Clement M, et al: Effect of dietary alpha-linolenic acid deficiency on habituation. Life Sci 58(21):1805–1816, 1996. 61. Yoshida S, Yasuda A, Kawazato H, et al: Synaptic vesicle ultrastructural changes in the rat hippocampus induced by a combination of alpha-linolenate deficiency and a learning task. J Neurochem 68(3):1261–1268, 1997. 62. Ikemoto A, Ohishi M, Sato Y, et al: Reversibility of n-3 fatty acid deficiencyinduced alterations of learning behavior in the rat: level of n-6 fatty acids as another critical factor. J Lipid Res 42(10):1655–1663, 2001. 63. Sato A, Osakabe T, Ikemoto A, et al: Long-term n-3 fatty acid deficiency induces no substantial change in the rate of protein synthesis in rat brain and liver. Biol Pharm Bull 22(8):775–779, 1999. 64. Greiner RS, Moriguchi T, Slotnick BM, et al: Olfactory discrimination deficits in n-3 fatty acid-deficient rats. Physiol Behav 72(3):379–385, 2001. 65. Catalan J, Moriguchi T, Slotnick B, et al: Cognitive deficits in docosahexaenoic acid-deficient rats. Behav Neurosci 116(6):1022–1031, 2002. 66. Greiner RS, Moriguchi T, Hutton A, et al: Rats with low levels of brain docosahexaenoic acid show impaired performance in olfactory-based and spatial learning tasks. Lipids 34(Suppl):S239–S243, 1999. 67. Salem N, Jr, et al: Alterations in brain function after loss of docosahexaenoate due to dietary restriction of n-3 fatty acids. J Mol Neurosci 16(2–3):299–307, discussion 317-221, 2001. 68. Yehuda S, Leprohon-Greenwood CE, Dixon LM, Coscina DV: Effects of dietary fat on pain threshold, thermoregulation and motor activity in rats. Pharmacol Biochem Behav 24(6):1775–1777, 1986. 69. Reisbick S, Neuringer M, Hasnain R, Connor WE: Home cage behavior of rhesus monkeys with long-term deficiency of omega-3 fatty acids. Physiol Behav 55(2):231–239, 1994. 70. Enslen M, Milon H, Malnoe A: Effect of low intake of n-3 fatty acids during development on brain phospholipid fatty acid composition and exploratory behavior in rats. Lipids 26(3):203–208, 1991. 71. Reisbick S, Neuringer M, Connor WE, Barstad L: Postnatal deficiency of omega-3 fatty acids in monkeys: fluid intake and urine concentration. Physiol Behav 51(3):473–479, 1992. 72. Hibbeln JR, Ferguson TA, Blasbalg TL: Omega-3 fatty acid deficiencies in neurodevelopment, aggression and autonomic dysregulation: opportunities for intervention. Int Rev Psychiatry 18(2):107–118, 2006. 73. Delion S, Chalon S, Hérault J, et al: Chronic dietary alpha-linolenic acid deficiency alters dopaminergic and serotoninergic neurotransmission in rats. J Nutr 124(12):2466–2476, 1994. 74. Delion S, Chalon S, Guilloteau D, et al: alpha-Linolenic acid dietary deficiency alters age-related changes of dopaminergic and serotoninergic neurotransmission in the rat frontal cortex. J Neurochem 66(4):1582–1591, 1996. 75. Levant B, Radel JD, Carlson SE: Decreased brain docosahexaenoic acid during development alters dopamine-related behaviors in adult rats that are differentially affected by dietary remediation. Behav Brain Res 152(1):49–57, 2004. 76. Papanikolaou Y, Brooks J, Reider C, Fulgoni VL, 3rd: U.S. adults are not meeting recommended levels for fish and omega-3 fatty acid intake: results of an analysis using observational data from NHANES 2003-2008. Nutr J 13:31, 2014. 77. Colombo J, Carlson SE: Is the measure the message: the BSID and nutritional interventions. Pediatrics 129(6):1166–1167, 2012. 78. Forsyth S: Why are we undertaking DHA supplementation studies in infants who are not DHA-deficient? Br J Nutr 108(5):948, 2012. 79. Mulder KA, King DJ, Innis SM: Omega-3 fatty acid deficiency in infants before birth identified using a randomized trial of maternal DHA supplementation in pregnancy. PLoS ONE 9(1):e83764, 2014. 80. Otto SJ, Houwelingen AC, Antal M, et al: Maternal and neonatal essential fatty acid status in phospholipids: an international comparative study. Eur J Clin Nutr 51(4):232–242, 1997. 81. Al MD, Badart-Smook A, von Houwelingen AC, et al: Fat intake of women during normal pregnancy: relationship with maternal and neonatal essential fatty acid status. J Am Coll Nutr 15(1):49–55, 1996. 82. Otto SJ, van Houwelingen AC, Badart-Smook A, Hornstra G: Changes in the maternal essential fatty acid profile during early pregnancy and the relation of the profile to diet. Am J Clin Nutr 73(2):302–307, 2001. 83. Al MD, van Houwelingen AC, Hornstra G: Long-chain polyunsaturated fatty acids, pregnancy, and pregnancy outcome. Am J Clin Nutr 71(1 Suppl):285s– 291s, 2000. 84. Hornstra G: Essential fatty acids in mothers and their neonates. Am J Clin Nutr 71(5 Suppl):1262s–1269s, 2000. 85. Zeijdner EE, van Houwelingen AC, Kester AD, Hornstra G: Essential fatty acid status in plasma phospholipids of mother and neonate after multiple pregnancy. Prostaglandins Leukot Essent Fatty Acids 56(5):395–401, 1997.

86. Haggarty P: Fatty acid supply to the human fetus. Annu Rev Nutr 30:237–255, 2010. 87. Kuipers RS, Luxwolda MF, Offringa PJ, et al: Gestational age dependent changes of the fetal brain, liver and adipose tissue fatty acid compositions in a population with high fish intakes. Prostaglandins Leukot Essent Fatty Acids 86(4–5):189–199, 2012. 88. Herrera E, Lasunción MA: Maternal-fetal transfer of lipid metaboites. In Polin RA, Abman SH, Rowitch D, Bentiz WE, editors: Fetal and neonatal physiology, ed 5, Philadelphia, 2017, Elsevier. 89. Lauritzen L, Carlson SE: Maternal fatty acid status during pregnancy and lactation and relation to newborn and infant status. Matern Child Nutr 7(Suppl 2):41–58, 2011. 90. Muhlhausler BS, Gibson RA, Yelland LN, Makrides M: Heterogeneity in cord blood DHA concentration: towards an explanation. Prostaglandins Leukot Essent Fatty Acids 91(4):135–140, 2014. 91. van Houwelingen AC, Foreman-van Drongelen MM, Nicolini U, et al: Essential fatty acid status of fetal plasma phospholipids: similar to postnatal values obtained at comparable gestational ages. Early Hum Dev 46(1–2):141–152, 1996. 92. Innis SM: Human milk and formula fatty acids. J Pediatr 120(4 Pt 2):S56–S61, 1992. 93. Xie L, Innis SM: Genetic variants of the FADS1 FADS2 gene cluster are associated with altered (n-6) and (n-3) essential fatty acids in plasma and erythrocyte phospholipids in women during pregnancy and in breast milk during lactation. J Nutr 138(11):2222–2228, 2008. 94. Koletzko B, Lattka E, Zeilinger S, et al: Genetic variants of the fatty acid desaturase gene cluster predict amounts of red blood cell docosahexaenoic and other polyunsaturated fatty acids in pregnant women: findings from the Avon Longitudinal Study of Parents and Children. Am J Clin Nutr 93(1):211– 219, 2011. 95. Scholtz SA, Kerling EH, Shaddy DJ, et al: Docosahexaenoic acid (DHA) supplementation in pregnancy differentially modulates arachidonic acid and DHA status across FADS genotypes in pregnancy. Prostaglandins Leukot Essent Fatty Acids 94:29–33, 2015. 96. Connor WE, Lowensohn R, Hatcher L: Increased docosahexaenoic acid levels in human newborn infants by administration of sardines and fish oil during pregnancy. Lipids 31(Suppl):S183–S187, 1996. 97. Harris WS, Connor WE, Lindsey S: Will dietary omega-3 fatty acids change the composition of human milk? Am J Clin Nutr 40(4):780–785, 1984. 98. Sanders TA, Ellis FR, Dickerson JW: Studies of vegans: the fatty acid composition of plasma choline phosphoglycerides, erythrocytes, adipose tissue, and breast milk, and some indicators of susceptibility to ischemic heart disease in vegans and omnivore controls. Am J Clin Nutr 31(5):805–813, 1978. 99. Ruan C, Liu X, Man H, et al: Milk composition in women from five different regions of China: the great diversity of milk fatty acids. J Nutr 125(12):2993– 2998, 1995. 100. Henderson RA, Jensen RG, Lammi-Keefe CJ, et al: Effect of fish oil on the fatty acid composition of human milk and maternal and infant erythrocytes. Lipids 27(11):863–869, 1992. 101. Brenna JT, Varamini B, Jensen RG, et al: Docosahexaenoic and arachidonic acid concentrations in human breast milk worldwide. Am J Clin Nutr 85(6):1457–1464, 2007. 102. Jensen RG: Milk lipids: human milk lipids, San Diego, Calif, USA, 1995, Academic Press. 103. Koletzko B, Thiel I, Abiodun PO: The fatty acid composition of human milk in Europe and Africa. J Pediatr 120(4 Pt 2):S62–S70, 1992. 104. Molto-Puigmarti C, Plat J, Mensink RP, et al: FADS1 FADS2 gene variants modify the association between fish intake and the docosahexaenoic acid proportions in human milk. Am J Clin Nutr 91(5):1368–1376, 2010. 105. Cheatham CL: FADS1/FADS2 single nucleotide polymorphisms as markers for fatty acid status of human milk. FASEB J 26:624–626, 2012. 106. Scholtz SA: (2012) Influence of FADS1 and FADS2 genotypes on maternal docosahexaenoic acid and infant developmental status. PhD dissertation (University of Kansas Medical Center). 107. Carlson SE, Rhodes PG, Ferguson MG: Docosahexaenoic acid status of preterm infants at birth and following feeding with human milk or formula. Am J Clin Nutr 44(6):798–804, 1986. 108. Liu CC, Carlson SE, Rhodes PG, et al: Increase in plasma phospholipid docosahexaenoic and eicosapentaenoic acids as a reflection of their intake and mode of administration. Pediatr Res 22(3):292–296, 1987. 109. Peeples JM, Werkman SH, Desiderio DM, et al: Effect of lCPUFA and age on red blood cell sphingomyelin 24:2 of preterm infants with reference to term infants. In PUFA in Infant Nutrition: Consensus and Controversies, Barcelona, Spain, 1996, AOCS Press, pp 33. 110. Ntoumani E, Strandvik B, Sabel KG: Nervonic acid is much lower in donor milk than in milk from mothers delivering premature infants—of neglected importance? Prostaglandins Leukot Essent Fatty Acids 89(4):241–244, 2013. 111. Blasbalg TL, Hibbeln JR, Ramsden CE, et al: Changes in consumption of omega-3 and omega-6 fatty acids in the United States during the 20th century. Am J Clin Nutr 93(5):950–962, 2011. 112. Sabel KG, Strandvik B, Petzold M, Lundqvist-Persson C: Motor, mental and behavioral developments in infancy are associated with fatty acid pattern in breast milk and plasma of premature infants. Prostaglandins Leukot Essent Fatty Acids 86(4–5):183–188, 2012. 113. Lassek WD, Gaulin SJ: Linoleic and docosahexaenoic acids in human milk have opposite relationships with cognitive test performance in a sample of



114. 115. 116. 117. 118. 119. 120. 121. 122. 123. 124. 125. 126. 127. 128. 129. 130. 131. 132. 133. 134.

135. 136. 137. 138.

139. 140.

141. 142.

Chapter 38 — Long-Chain Polyunsaturated Fatty Acids in the Developing Central Nervous System 28 countries. Prostaglandins Leukot Essent Fatty Acids 91(5):195–201, 2014. Ou X, Andres A, Cleves MA, et al: Sex-specific association between infant diet and white matter integrity in 8-y-old children. Pediatr Res 76(6):535–543, 2014. Carlson SE, Cooke RJ, Rhodes PG, et al: Long-term feeding of formulas high in linolenic acid and marine oil to very low birth weight infants: phospholipid fatty acids. Pediatr Res 30(5):404–412, 1991. Carlson SE, Werkman SH, Peeples JM, et al: Arachidonic acid status correlates with first year growth in preterm infants. Proc Natl Acad Sci U S A 90(3):1073–1077, 1993. Leaf AA, Leighfield MJ, Costeloe KL, Crawford MA: Long chain polyunsaturated fatty acids and fetal growth. Early Hum Dev 30(3):183–191, 1992. Carlson SE, Rhodes PG, Rao VS, Goldgar DE: Effect of fish oil supplementation on the n-3 fatty acid content of red blood cell membranes in preterm infants. Pediatr Res 21(5):507–510, 1987. O’Connor DL, Hall R, Adamkin D, et al: Growth and development in preterm infants fed long-chain polyunsaturated fatty acids: a prospective, randomized controlled trial. Pediatrics 108(2):359–371, 2001. Ponder DL, Innis SM, Benson JD, Siegman JS: Docosahexaenoic acid status of term infants fed breast milk or infant formula containing soy oil or corn oil. Pediatr Res 32(6):683–688, 1992. Martinez M, Ballabriga A: Effects of parenteral nutrition with high doses of linoleate on the developing human liver and brain. Lipids 22(3):133–138, 1987. Carlson SE: Arachidonic acid status of human infants: influence of gestational age at birth and diets with very long chain n-3 and n-6 fatty acids. J Nutr 126(4 Suppl):1092s–1098s, 1996. Koletzko B, Braun M: Arachidonic acid and early human growth: is there a relation? Ann Nutr Metab 35(3):128–131, 1991. Carlson SE, Werkman SH, Tolley EA: Effect of long-chain n-3 fatty acid supplementation on visual acuity and growth of preterm infants with and without bronchopulmonary dysplasia. Am J Clin Nutr 63(5):687–697, 1996. Lapillonne A, Carlson SE: Polyunsaturated fatty acids and infant growth. Lipids 36(9):901–911, 2001. Martinez M, Mougan I: Fatty acid composition of human brain phospholipids during normal development. J Neurochem 71(6):2528–2533, 1998. Svennerholm L: Distribution and fatty acid composition of phosphoglycerides in normal human brain. J Lipid Res 9(5):570–579, 1968. Hsieh AT, Anthony JC, Diersen-Schade DA, et al: The influence of moderate and high dietary long chain polyunsaturated fatty acids (LCPUFA) on baboon neonate tissue fatty acids. Pediatr Res 61(5 Pt 1):537–545, 2007. Mohrhauer H, Holman RT: Alteration of the fatty acid composition of brain lipids by varying levels of dietary essential fatty acids. J Neurochem 10:523– 530, 1963. Century B, Witting LA, Harvey CC, Horwitt MK: Interrelationships of dietary lipids upon fatty acid composition of brain mitochondria, erythrocytes and heart tissue in chicks. Am J Clin Nutr 13:362–368, 1963. Wainwright PE, Xing HC, Mutsaers L, et al: Arachidonic acid offsets the effects on mouse brain and behavior of a diet with a low (n-6):(n-3) ratio and very high levels of docosahexaenoic acid. J Nutr 127(1):184–193, 1997. Arbuckle LD, Innis SM: Docosahexaenoic acid in developing brain and retina of piglets fed high or low alpha-linolenate formula with and without fish oil. Lipids 27(2):89–93, 1992. Makrides M, Simmer K, Goggin M, Gibson RA: Erythrocyte docosahexaenoic acid correlates with the visual response of healthy, term infants. Pediatr Res 33(4 Pt 1):425–427, 1993. Smithers LG, Gibson RA, McPhee A, Makrides M: Higher dose of docosahexaenoic acid in the neonatal period improves visual acuity of preterm infants: results of a randomized controlled trial. Am J Clin Nutr 88(4):1049–1056, 2008. Werkman SH, Carlson SE: A randomized trial of visual attention of preterm infants fed docosahexaenoic acid until nine months. Lipids 31(1):91–97, 1996. Jorgensen MH, Hernell O, Lund P, et al: Visual acuity and erythrocyte docosahexaenoic acid status in breast-fed and formula-fed term infants during the first four months of life. Lipids 31(1):99–105, 1996. Innis SM, Gilley J, Werker J: Are human milk long-chain polyunsaturated fatty acids related to visual and neural development in breast-fed term infants? J Pediatr 139(4):532–538, 2001. Williams C, Birch EE, Emmett PM, Northstone K: Stereoacuity at age 3.5 y in children born full-term is associated with prenatal and postnatal dietary factors: a report from a population-based cohort study. Am J Clin Nutr 73(2):316–322, 2001. Jacques C, Levy E, Muckle G, et al: Long-term effects of prenatal omega-3 fatty acid intake on visual function in school-age children. J Pediatr 158(1):83–90, 90.e81, 2011. Cheatham CL: (Electrophysiological evidence of the influence of maternal FADS2 genotype on the memory abilities of breastfed 6-month-olds. Presented at the 2012 International Conference on Infant Studies, Minneapolis, Minnesota, June 7-9, 2012. Gustafson KM, Colombo J, Carlson SE, et al: A randomized controlled trial of DHA supplementation during pregnancy: visual acuity development. Gustafson KM, Colombo J, Carlson SE: Docosahexaenoic acid and cognitive function: Is the link mediated by the autonomic nervous system? Prostaglandins Leukot Essent Fatty Acids 79(3–5):135–140, 2008.

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143. Stein AD, Wang M, Rivera JA, et al: Auditory- and visual-evoked potentials in Mexican infants are not affected by maternal supplementation with 400 mg/d docosahexaenoic acid in the second half of pregnancy. J Nutr 142(8):1577– 1581, 2012. 144. Hoffman DR, Birch EE, Birch DG, et al: Impact of early dietary intake and blood lipid composition of long-chain polyunsaturated fatty acids on later visual development. J Pediatr Gastroenterol Nutr 31(5):540–553, 2000. 145. Birch EE, Castaneda YS, Wheaton DH, et al: Visual maturation of term infants fed long-chain polyunsaturated fatty acid-supplemented or control formula for 12 mo. Am J Clin Nutr 81(4):871–879, 2005. 146. Auestad N, Montalto MB, Hall RT, et al: Visual acuity, erythrocyte fatty acid composition, and growth in term infants fed formulas with long chain polyunsaturated fatty acids for one year. Ross Pediatric Lipid Study. Pediatr Res 41(1):1–10, 1997. 147. Auestad N, Halter R, Hall RT, et al: Growth and development in term infants fed long-chain polyunsaturated fatty acids: a double-masked, randomized, parallel, prospective, multivariate study. Pediatrics 108(2):372–381, 2001. 148. Scott DT, Janowsky JS, Carroll RE, et al: Formula supplementation with longchain polyunsaturated fatty acids: are there developmental benefits? Pediatrics 102(5):E59, 1998. 149. Tolley EA, Carlson SE: Considerations of statistical power in infant studies of visual acuity development and docosahexaenoic acid status. Am J Clin Nutr 71(1):1–2, 2000. 150. Carlson SE, Werkman SH: A randomized trial of visual attention of preterm infants fed docosahexaenoic acid until two months. Lipids 31(1):85–90, 1996. 151. Colombo J: Recent advances in infant cognition: implications for long-chain polyunsaturated fatty acid supplementation studies. Lipids 36(9):919–926, 2001. 152. Thelen ESL: Dynamic Systems Approachto the Development of Cognition and Action, 1994, MIT Press. 153. Escolano-Margarit MV, Ramos R, Beyer J, et al: Prenatal DHA status and neurological outcome in children at age 5.5 years are positively associated. J Nutr 141(6):1216–1223, 2011. 154. van Goor SA, Djick-Brouwer DA, Doornbos B, et al: Supplementation of DHA but not DHA with arachidonic acid during pregnancy and lactation influences general movement quality in 12-week-old term infants. Br J Nutr 103(2):235– 242, 2010. 155. van Goor SA, Dijck-Brouwer DA, Erwich JJ, et al: The influence of supplemental docosahexaenoic and arachidonic acids during pregnancy and lactation on neurodevelopment at eighteen months. Prostaglandins Leukot Essent Fatty Acids 84(5–6):139–146, 2011. 156. Bouwstra H, Dijck-Brouwer J, Decsi T, et  al: Neurologic condition of healthy term infants at 18 months: positive association with venous umbilical DHA status and negative association with umbilical trans-fatty acids. Pediatr Res 60(3):334–339, 2006. 157. Bouwstra H, Djick-Brouwer, Decsi T, et al: Relationship between umbilical cord essential fatty acid content and the quality of general movements of healthy term infants at 3 months. Pediatr Res 59(5):717–722, 2006. 158. Kohlboeck G, Glaser C, Tiesler C, et al: Effect of fatty acid status in cord blood serum on children’s behavioral difficulties at 10 y of age: results from the LISAplus Study. Am J Clin Nutr 94(6):1592–1599, 2011. 159. Steenweg-de Graaff JC, Tiemeier H, Basten MG, et al: Maternal LC-PUFA status during pregnancy and child problem behavior: the Generation R Study. Pediatr Res 77(3):489–497, 2015. 160. Makrides M, Gould Jr, Gawlik NR, et al: Four-year follow-up of children born to women in a randomized trial of prenatal DHA supplementation. JAMA 311(17):1802–1804, 2014. 161. Colombo JCC: Infant cognition: predicting later intellectual functioning, San Diego, California, USA, 2006, Academic Press. 162. Breckenridge WC, Gombos G, Morgan IG: The lipid composition of adult rat brain synaptosomal plasma membranes. Biochim Biophys Acta 266(3):695– 707, 1972. 163. Itokazu N, Ikegaya Y, Nishikawa M, Matsuki N: Bidirectional actions of docosahexaenoic acid on hippocampal neurotransmissions in vivo. Brain Res 862(1–2):211–216, 2000. 164. Martinez M: Tissue levels of polyunsaturated fatty acids during early human development. J Pediatr 120(4 Pt 2):S129–S138, 1992. 165. Nieoullon A: Dopamine and the regulation of cognition and attention. Prog Neurobiol 67(1):53–83, 2002. 166. Tuladhar AM, van Norden AG, de Laat KF, et al: White matter integrity in small vessel disease is related to cognition. Neuroimage Clin 7:518–524, 2015. 167. Brauer J, Anwander A, Friederici AD: Neuroanatomical prerequisites for language functions in the maturing brain. Cereb Cortex 21(2):459–466, 2011. 168. Santiago C, Herrmann N, Swardfager W, et al: White matter microstructural integrity is associated with executive function and processing speed in older adults with coronary artery disease. Am J Geriatr Psychiatry 23(7):754–763, 2015. 169. Bauer IE, Ouyang A, Mwangi B, et al: Reduced white matter integrity and verbal fluency impairment in young adults with bipolar disorder: a diffusion tensor imaging study. J Psychiatr Res 62:115–122, 2015. 170. Rae CL, Hughes LE, Anderson MC, Rowe JB: The prefrontal cortex achieves inhibitory control by facilitating subcortical motor pathway connectivity. J Neurosci 35(2):786–794, 2015.

389.e4 SECTION VI — Lipid Metabolism 171. Francx W, Zwiers MP, Mennes M, et al: White matter microstructure and developmental improvement of hyperactive/impulsive symptoms in attentiondeficit/hyperactivity disorder. J Child Psychol Psychiatry 2015 Jan 10. [Epub ahead of print]. 172. Martinez M, Vásquez E, Garcia-Silva MT, et al: Therapeutic effects of docosahexaenoic acid ethyl ester in patients with generalized peroxisomal disorders. Am J Clin Nutr 71(1 Suppl):376s–385s, 2000. 173. Martinez M, Vazquez E: MRI evidence that docosahexaenoic acid ethyl ester improves myelination in generalized peroxisomal disorders. Neurology 51(1):26–32, 1998. 174. Peters BD, Voineskos AN, Szeszko PR, et al: Brain white matter development is associated with a human-specific haplotype increasing the synthesis of long chain fatty acids. Journal Neurosci 34(18):6367–6376, 2014. 175. Cheruku SR, Montgomery-Downs HE, Farkas SL, et al: Higher maternal plasma docosahexaenoic acid during pregnancy is associated with more mature neonatal sleep-state patterning. Am J Clin Nutr 76(3):608–613, 2002. 176. Judge MP, Cong X, Harel O, et al: Maternal consumption of a DHA-containing functional food benefits infant sleep patterning: an early neurodevelopmental measure. Early Hum Dev 88(7):531–537, 2012. 177. Gustafson KM, Carlson SE, Colombo J, et al: Effects of docosahexaenoic acid supplementation during pregnancy on fetal heart rate and variability: a randomized clinical trial. Prostaglandins Leukot Essent Fatty Acids 88(5):331– 338, 2013. 178. Wood JT, Williams JS, Pandarinathan L, et al: Dietary docosahexaenoic acid supplementation alters select physiological endocannabinoid-system metabolites in brain and plasma. J Lipid Res 51(6):1416–1423, 2010. 179. Kim HY, Spector AA, Xiong ZM: A synaptogenic amide Ndocosahexaenoylethanolamide promotes hippocampal development. Prostaglandins Other Lipid Mediat 96(1–4):114–120, 2011. 180. Kim HY, Moon HS, Cao D, et al: N-Docosahexaenoylethanolamide promotes development of hippocampal neurons. Biochem J 435(2):327–336, 2011. 181. Kim HY, Huang BX, Spector AA: Phosphatidylserine in the brain: metabolism and function. Prog Lipid Res 56:1–18, 2014. 182. Innis SM: Perinatal biochemistry and physiology of long-chain polyunsaturated fatty acids. J Pediatr 143(4 Suppl):S1–S8, 2003. 183. Meldrum SJ, D’Vaz N, Simmer K, et al: Effects of high-dose fish oil supplementation during early infancy on neurodevelopment and language: a randomised controlled trial. Br J Nutr 108(8):1443–1454, 2012. 184. Auestad N, Scott DT, Janowsky JS, et al: Visual, cognitive, and language assessments at 39 months: a follow-up study of children fed formulas containing long-chain polyunsaturated fatty acids to 1 year of age. Pediatrics 112(3 Pt 1):e177–e183, 2003. 185. Lauritzen L, Jorgensen MH, Mikkelsen TB, et al: Maternal fish oil supplementation in lactation: effect on visual acuity and n-3 fatty acid content of infant erythrocytes. Lipids 39(3):195–206, 2004. 186. Drover JR, et al: A randomized trial of DHA intake during infancy: School readiness and receptive vocabulary at 2–3.5 years of age. Early Hum Dev 88(11):885–891, 2012. 187. Davidson PW, Felius J, Hoffman DR, et al: Effects of prenatal and postnatal methylmercury exposure from fish consumption on neurodevelopment: outcomes at 66 months of age in the Seychelles Child Development Study. JAMA 280(8):701–707, 1998. 188. Strain JJ, et al: Maternal PUFA status but not prenatal methylmercury exposure is associated with children’s language functions at age five years in the Seychelles. J Nutr 142(11):1943–1949, 2012. 189. Colombo J, Carlson SE, Cheatham CL, et al: Long-term effects of LCPUFA supplementation on childhood cognitive outcomes. Am J Clin Nutr 98(2):403–412, 2013. 190. Morales E, et al: Genetic variants of the FADS gene cluster and ELOVL gene family, colostrums LC-PUFA levels, breastfeeding, and child cognition. PLoS ONE 6(2):e17181, 2011. 191. Colombo J: Infant cognition: predicting later intellectual functioning, Thousand Oaks, Calif, USA, 1993, Sage. 192. Colombo J, Shaddy DJ, Blaga OM, et al: Early attentional predictors of vocabulary in childhood. In Infant pathways to language: methods, models and research directions, New York, 2009, Erlbaum, pp 143–167. 193. Colombo JSD, Richman WA, Maikranz JM, Blaga OM: The developmental course of habituation in infancy and preschool outcome. Infancy 5(1):1–38, 2004. 194. Colombo J, Kannass KN, Shaddy DJ, et al: Maternal DHA and the development of attention in infancy and toddlerhood. Child Dev 75(4):1254–1267, 2004. 195. Kannass KN, Colombo J, Carlson SE: Maternal DHA levels and toddler freeplay attention. Dev Neuropsychol 34(2):159–174, 2009. 196. Minns LM, et al: Toddler formula supplemented with docosahexaenoic acid (DHA) improves DHA status and respiratory health in a randomized, doubleblind, controlled trial of US children less than 3 years of age. Prostaglandins Leukot Essent Fatty Acids 82(4–6):287–293, 2010. 197. Gould JF, Makrides M, Colombo J, Smithers LG: Randomized controlled trial of maternal omega-3 long-chain PUFA supplementation during pregnancy and early childhood development of attention, working memory, and inhibitory control. Am J Clin Nutr 99(4):851–859, 2014. 198. Colombo J, Carlson SE, Cheatham CL, et al: Long-chain polyunsaturated fatty acid supplementation in infancy reduces heart rate and positively affects distribution of attention. Pediatr Res 70(4):406–410, 2011.

199. Bayley N: Bayley scales of infant development, ed 2, 1993, Psychological Corporation. 200. Bayley N: Bayley scales of infant development, ed 3, San Antonio, Tex, 2006, Harcourt Assessments. 201. Agostoni C, Trojan S, Bellu R, et al: Neurodevelopmental quotient of healthy term infants at 4 months and feeding practice: the role of long-chain polyunsaturated fatty acids. Pediatr Res 38(2):262–266, 1995. 202. Birch EE, Garfield S, Hoffman DR, et al: A randomized controlled trial of early dietary supply of long-chain polyunsaturated fatty acids and mental development in term infants. Dev Med Child Neurol 42(3):174–181, 2000. 203. Clandinin MT, Van Aerde JE, Merkel KL, et al: Growth and development of preterm infants fed infant formulas containing docosahexaenoic acid and arachidonic acid. J Pediatr 146(4):461–468, 2005. 204. Cohen JT, Bellinger DC, Connor WE, Shaywitz BA: A quantitative analysis of prenatal intake of n-3 polyunsaturated fatty acids and cognitive development. Am J Prev Med 29(4):366–374, 2005. 205. Drover JR, Hoffman DR, Castaneda YS, et al: Cognitive function in 18-monthold term infants of the DIAMOND study: a randomized, controlled clinical trial with multiple dietary levels of docosahexaenoic acid. Early Hum Dev 87(3):223–230, 2011. 206. Forsyth JS, Willatts P, DiModogno MK, et al: Do long-chain polyunsaturated fatty acids influence infant cognitive behaviour? Biochem Soc Trans 26(2):252–257, 1998. 207. Willatts P, Forsyth JS, DiModugno MK, et al: Effect of long-chain polyunsaturated fatty acids in infant formula on problem solving at 10 months of age. Lancet 352(9129):688–691, 1998. 208. Willatts P, Forsyth JS, DiModugno MK, et al: Influence of long-chain polyunsaturated fatty acids on infant cognitive function. Lipids 33(10):973–980, 1998. 209. Gustafsson PA, Duchen K, Birberg U, Karlsson T: Breastfeeding, very long polyunsaturated fatty acids (PUFA) and IQ at 6 1/2 years of age. Acta Paediatr 93(10):1280–1287, 2004. 210. Stokes-Riner A, Thurston SW, Myers GJ, et al: A longitudinal analysis of prenatal exposure to methylmercury and fatty acids in the Seychelles. Neurotoxicol Teratol 33(2):325–328, 2011. 211. Bakker EC, Hornstra G, Blanco CE, Vles JS: Relationship between long-chain polyunsaturated fatty acids at birth and motor function at 7 years of age. Eur J Clin Nutr 63(4):499–504, 2009. 212. Steer CD, Lattka E, Koletzko B, et al: Maternal fatty acids in pregnancy, FADS polymorphisms, and child intelligence quotient at 8 y of age. Am J Clin Nutr 98(6):1575–1582, 2013. 213. Boucher O, Burden MJ, Muckle G, et al: Neurophysiologic and neurobehavioral evidence of beneficial effects of prenatal omega-3 fatty acid intake on memory function at school age. Am J Clin Nutr 93(5):1025–1037, 2011. 214. Rees A, Sirois S, Wearden A: Maternal docosahexaenoic acid intake levels during pregnancy and infant performance on a novel object search task at 22 months. Child Dev 85(6):2131–2139, 2014. 215. Dunstan JA, Simmer K, Dixon G, Prescott SL: Cognitive assessment of children at age 2(1/2) years after maternal fish oil supplementation in pregnancy: a randomised controlled trial. Arch Dis Child Fetal Neonatal Ed 93(1):F45– F50, 2008. 216. Helland IB, Smith L, Saarem K, et al: Maternal supplementation with verylong-chain n-3 fatty acids during pregnancy and lactation augments children’s IQ at 4 years of age. Pediatrics 111(1):e39–e44, 2003. 217. Helland IB, Smith L, Blomén B, et al: Effect of supplementing pregnant and lactating mothers with n-3 very-long-chain fatty acids on children’s IQ and body mass index at 7 years of age. Pediatrics 122(2):e472–e479, 2008. 218. Campoy C, Escolano-Margarit MV, Ramos R, et al: Effects of prenatal fish-oil and 5-methyltetrahydrofolate supplementation on cognitive development of children at 6.5 y of age. Am J Clin Nutr 94(6 Suppl):1880s–1888s, 2011. 219. Gale CR, Marriott LD, Martyn CN, et al: Breastfeeding, the use of docosahexaenoic acid-fortified formulas in infancy and neuropsychological function in childhood. Arch Dis Child 95(3):174–179, 2010. 220. Jensen CL, Voigt RG, Prager TC, et al: Effects of maternal docosahexaenoic acid intake on visual function and neurodevelopment in breastfed term infants. Am J Clin Nutr 82(1):125–132, 2005. 221. Jensen CL, Voigt RG, Llorente AM, et al: Effects of early maternal docosahexaenoic acid intake on neuropsychological status and visual acuity at five years of age of breast-fed term infants. J Pediatr 157(6):900–905, 2010. 222. Willatts P, Forsyth S, Agostini C, et al: Effects of long-chain PUFA supplementation in infant formula on cognitive function in later childhood. Am J Clin Nutr 98(2):536s–542s, 2013. 223. de Jong C, Kikkert HK, Fidler V, Hadders-Algra M: Effects of long-chain polyunsaturated fatty acid supplementation of infant formula on cognition and behaviour at 9 years of age. Dev Med Child Neurol 54(12):1102–1108, 2012. 224. de Jong C, Kikkert HK, Fidler V, Hadders-Algra M: The Groningen LCPUFA study: no effect of postnatal long-chain polyunsaturated fatty acids in healthy term infants on neurological condition at 9 years. Br J Nutr 104(4):566–572, 2010. 225. Cheatham CL, Nerhammer AS, Asserhoj M, et al: Fish oil supplementation during lactation: effects on cognition and behavior at 7 years of age. Lipids 46(7):637–645, 2011. 226. Liao KMB, McCandliss BD, Carlson SE, et al: Event-related potential differences in children supplemented with long-chain polyunsaturated fatty acids during infancy. Devel Sci (in press).