- Email: [email protected]
Cognitive and brain ageing – how does diet matter?
Abstracts / Journal of Nutrition & Intermediary Metabolism 8 (2017) 60e121
last 50 years, which is too short a time for evolutionary change in digestive physiology. Short-term adaptation to recent dramatic dietary changes has proven insufficient to avoid deleterious effects leading to obesity, diabetes, fatty liver disease and the metabolic syndrome. In fact, obesity and associated diseases may be enhanced by the inheritance of epigenetic changes. EPIGENETICS AND DIETARY POLYUNSATURATED FATTY ACIDS G.C. Burdge. Academic Unit of Human Development and Health, University of Southampton, Southampton, UK E-mail address: [email protected] Background: Dietary fatty acids can alter cell function through membrane fluidity, by providing substrates for synthesis of second messengers and by activation or repression of transcription factors. Recent studies show that fatty acids can also modify the epigenetic processes. This talk will review these findings by focussing on the interaction between polyunsaturated fatty acids (PUFA) and the epigenome. Results: Feeding pregnant rats diets with graded fish oil content induced increased DNA methylation of specific loci in FADS2 in adult offspring liver leading to lower transcription and reduced PUFA biosynthesis. However, such effects were transient in adult rats. Feeding men and women n-3 PUFA ethyl esters (3.5 g/day) for 8 weeks altered DNA methylation of specific loci in the FADS2 and ELOVL5 genes compared to olive oil (4 g/day) in leukocytes, contingent on sex. Women have higher capacity for docosahexaenoic acid (DHA) synthesis than men, which may be important for supply of DHA from mother to offspring. Progesterone induced reduced methylation of specific loci in the FADS2 promoter leading to increased expression and higher PUFA synthesis in HepG2 cells and primarily human hepatocytes. Preliminary findings suggest that induction of higher DHA synthesis in girls occurs during puberty and that this involves demethylation of FADS2. Conclusions: Together these findings show that fatty acids can modify PUFA biosynthesis via changes in DNA methylation. This has implications for the capacity of a mother to meet the demands of her offspring for PUFA and for personalised nutrition. Funding source(s): British Heart Foundation; Nutricia Research Foundation.
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fitness’. Absence of or inadequate early microbial stimuli has been shown to cause defects in intestinal barrier function, reduced inflammatory responses, defective IgA responses and deficient oral tolerance induction. Mice raised in a germ free environment fail to develop oral tolerance. This immune dysregulation can be corrected by reconstitution of intestinal microbiota, but only if this occurs during the neonatal period. Alterations in the intestinal microbiota composition (particularly Bifidobacteria species) and a reduced intestinal microbial diversity in early life have been associated with later development of various non-communicable diseases. The process of colonization and the types of organisms that become established are influenced by many factors including mode of delivery (vaginal or Caesarean section), mother’s diet including use of probiotics, whether the infant is formula or breast-fed and the subsequent infant diet. Recent studies suggest that diet plays a central role in regulating immune homeostasis through shaping the intestinal microbiota, supporting the production of microbial metabolites (short chain fatty acids) and via direct effects on immune cells. Intestinal microbial composition is predominantly shaped by the long term diet while short term dietary changes induce modest transient shifts in composition. Certain bacterial genus groups can digest soluble dietary fiber to produce short chain fatty acids which have potent immune effects that support tolerance and immune homeostasis. Diets high in fiber are associated with increased production of tolerance promoting short chain fatty acids, particularly butyrate and acetate, increased numbers of peripheral T regulatory cells and a reduced risk of NCD. Dietary components can also modulate immune responses directly by binding to the aryl hydrocarbon receptor. Summary: Early life nutrition and intestinal microbial composition play important roles in determining risk of NCD in later life. The first 1000 days of life represents an important window of time when environmental exposures have greatest impact on disease risk and hence offer an opportunity for prevention of disease.
Plenary 5: Food and ageing COGNITIVE AND BRAIN AGEING e HOW DOES DIET MATTER? K. Anstey. Centre for Research on Ageing, Health and Wellbeing, Research School of Population Health, The Australian National University, ACT, Australia E-mail address: [email protected]
ROLE OF NUTRITION IN TOLERANCE DEVELOPMENT M. Tang. Murdoch Children’s Research Institute, Royal Children's Hospital, Parkville, VIC, Australia E-mail address: [email protected] ‘Immune homeostasis’ refers to the critical balance between tolerance to commensal microbes or food antigens and vigilance against pathogens. Effective homeostasis is associated with a healthy inflammatory tone that allows a rapid and self-limiting response to harmful encounters while protecting against unwanted inflammatory responses. Disturbance of these regulatory circuits leads to dysregulation of immune tolerance and an altered inflammatory tone with inadequately restrained inflammation; which are in turn associated with development of a range of immune-mediated and metabolic diseases referred to collectively as non-communicable diseases. The non-communicable diseases (NCD) include allergic diseases (e.g. asthma, eczema, food allergy), autoimmune diseases (e.g. IDDM, multiple sclerosis), metabolic disorders (e.g. obesity, cardiovascular disease, stroke), other immune mediated conditions (inflammatory bowel disease) and neurodevelopmental conditions. Prevalence of these conditions has increased dramatically in the second half of the 20th century. Studies suggest that the environment in early life strongly affects one’s subsequent risk of developing NCD and play a much stronger determining role than later environmental influences or genetic inheritance. In particular, nutrition and intestinal microbial composition in early life have been shown to play important roles. The period from conception to the second birthday (referred to as the ‘first 1000 days’) has been proposed as a critical time for determining long term disease risk trajectory. Establishment of the intestinal microbiota in the early neonatal period is essential for establishment of healthy immune homeostasis or ‘immune
Background/Aims: There is increasing interest in how individual nutrients and dietary patterns impact on cognitive and brain health in ageing. In this talk I will provide an overview of the normal changes in cognition in later life and transitions to cognitive impairment and dementia. I will discuss how current evidence on nutrition fits in with what we know about risk factors for cognitive decline and dementia. Methods: Findings from the literature as well as findings from two population-based studies in Australia will be discussed e PATH Through Life and AusDiab. I will emphasise methodological considerations for interpreting this literature. Results: There has been support for the Mediterranean diet and the MIND diet as protective against incident dementia and brain aging. Studies have linked higher fruit, vegetable and fish intake with less cognitive decline. However, we still lack sufficient data to conduct systematic reviews and very few randomised controlled trials have been conducted on this topic to date. Our analysis of two large Australian cohorts did not find a protective effect of the Mediterranean diet on cognitive function. There is growing evidence in animal and human studies that a junk food diet leads to poorer brain health. Conclusions: Current evidence is limited and inconclusive but general findings in the field of cognitive aging and dementia are largely consistent with those from cancer, heart disease and stroke. Funding source(s): National Health and Medical Research Council and Australian Research Council NUTRITIONAL CHALLENGES OF THE GERIATRIC EQUINE ATHLETE E. Owens. Equine Research Unit, School of Agriculture and Food Sciences, The University of Queensland, Gatton, QLD, Australia
last 50 years, which is too short a time for evolutionary change in digestive physiology. Short-term adaptation to recent dramatic dietary changes has proven insufficient to avoid deleterious effects leading to obesity, diabetes, fatty liver disease and the metabolic syndrome. In fact, obesity and associated diseases may be enhanced by the inheritance of epigenetic changes. EPIGENETICS AND DIETARY POLYUNSATURATED FATTY ACIDS G.C. Burdge. Academic Unit of Human Development and Health, University of Southampton, Southampton, UK E-mail address: [email protected] Background: Dietary fatty acids can alter cell function through membrane fluidity, by providing substrates for synthesis of second messengers and by activation or repression of transcription factors. Recent studies show that fatty acids can also modify the epigenetic processes. This talk will review these findings by focussing on the interaction between polyunsaturated fatty acids (PUFA) and the epigenome. Results: Feeding pregnant rats diets with graded fish oil content induced increased DNA methylation of specific loci in FADS2 in adult offspring liver leading to lower transcription and reduced PUFA biosynthesis. However, such effects were transient in adult rats. Feeding men and women n-3 PUFA ethyl esters (3.5 g/day) for 8 weeks altered DNA methylation of specific loci in the FADS2 and ELOVL5 genes compared to olive oil (4 g/day) in leukocytes, contingent on sex. Women have higher capacity for docosahexaenoic acid (DHA) synthesis than men, which may be important for supply of DHA from mother to offspring. Progesterone induced reduced methylation of specific loci in the FADS2 promoter leading to increased expression and higher PUFA synthesis in HepG2 cells and primarily human hepatocytes. Preliminary findings suggest that induction of higher DHA synthesis in girls occurs during puberty and that this involves demethylation of FADS2. Conclusions: Together these findings show that fatty acids can modify PUFA biosynthesis via changes in DNA methylation. This has implications for the capacity of a mother to meet the demands of her offspring for PUFA and for personalised nutrition. Funding source(s): British Heart Foundation; Nutricia Research Foundation.
65
fitness’. Absence of or inadequate early microbial stimuli has been shown to cause defects in intestinal barrier function, reduced inflammatory responses, defective IgA responses and deficient oral tolerance induction. Mice raised in a germ free environment fail to develop oral tolerance. This immune dysregulation can be corrected by reconstitution of intestinal microbiota, but only if this occurs during the neonatal period. Alterations in the intestinal microbiota composition (particularly Bifidobacteria species) and a reduced intestinal microbial diversity in early life have been associated with later development of various non-communicable diseases. The process of colonization and the types of organisms that become established are influenced by many factors including mode of delivery (vaginal or Caesarean section), mother’s diet including use of probiotics, whether the infant is formula or breast-fed and the subsequent infant diet. Recent studies suggest that diet plays a central role in regulating immune homeostasis through shaping the intestinal microbiota, supporting the production of microbial metabolites (short chain fatty acids) and via direct effects on immune cells. Intestinal microbial composition is predominantly shaped by the long term diet while short term dietary changes induce modest transient shifts in composition. Certain bacterial genus groups can digest soluble dietary fiber to produce short chain fatty acids which have potent immune effects that support tolerance and immune homeostasis. Diets high in fiber are associated with increased production of tolerance promoting short chain fatty acids, particularly butyrate and acetate, increased numbers of peripheral T regulatory cells and a reduced risk of NCD. Dietary components can also modulate immune responses directly by binding to the aryl hydrocarbon receptor. Summary: Early life nutrition and intestinal microbial composition play important roles in determining risk of NCD in later life. The first 1000 days of life represents an important window of time when environmental exposures have greatest impact on disease risk and hence offer an opportunity for prevention of disease.
Plenary 5: Food and ageing COGNITIVE AND BRAIN AGEING e HOW DOES DIET MATTER? K. Anstey. Centre for Research on Ageing, Health and Wellbeing, Research School of Population Health, The Australian National University, ACT, Australia E-mail address: [email protected]
ROLE OF NUTRITION IN TOLERANCE DEVELOPMENT M. Tang. Murdoch Children’s Research Institute, Royal Children's Hospital, Parkville, VIC, Australia E-mail address: [email protected] ‘Immune homeostasis’ refers to the critical balance between tolerance to commensal microbes or food antigens and vigilance against pathogens. Effective homeostasis is associated with a healthy inflammatory tone that allows a rapid and self-limiting response to harmful encounters while protecting against unwanted inflammatory responses. Disturbance of these regulatory circuits leads to dysregulation of immune tolerance and an altered inflammatory tone with inadequately restrained inflammation; which are in turn associated with development of a range of immune-mediated and metabolic diseases referred to collectively as non-communicable diseases. The non-communicable diseases (NCD) include allergic diseases (e.g. asthma, eczema, food allergy), autoimmune diseases (e.g. IDDM, multiple sclerosis), metabolic disorders (e.g. obesity, cardiovascular disease, stroke), other immune mediated conditions (inflammatory bowel disease) and neurodevelopmental conditions. Prevalence of these conditions has increased dramatically in the second half of the 20th century. Studies suggest that the environment in early life strongly affects one’s subsequent risk of developing NCD and play a much stronger determining role than later environmental influences or genetic inheritance. In particular, nutrition and intestinal microbial composition in early life have been shown to play important roles. The period from conception to the second birthday (referred to as the ‘first 1000 days’) has been proposed as a critical time for determining long term disease risk trajectory. Establishment of the intestinal microbiota in the early neonatal period is essential for establishment of healthy immune homeostasis or ‘immune
Background/Aims: There is increasing interest in how individual nutrients and dietary patterns impact on cognitive and brain health in ageing. In this talk I will provide an overview of the normal changes in cognition in later life and transitions to cognitive impairment and dementia. I will discuss how current evidence on nutrition fits in with what we know about risk factors for cognitive decline and dementia. Methods: Findings from the literature as well as findings from two population-based studies in Australia will be discussed e PATH Through Life and AusDiab. I will emphasise methodological considerations for interpreting this literature. Results: There has been support for the Mediterranean diet and the MIND diet as protective against incident dementia and brain aging. Studies have linked higher fruit, vegetable and fish intake with less cognitive decline. However, we still lack sufficient data to conduct systematic reviews and very few randomised controlled trials have been conducted on this topic to date. Our analysis of two large Australian cohorts did not find a protective effect of the Mediterranean diet on cognitive function. There is growing evidence in animal and human studies that a junk food diet leads to poorer brain health. Conclusions: Current evidence is limited and inconclusive but general findings in the field of cognitive aging and dementia are largely consistent with those from cancer, heart disease and stroke. Funding source(s): National Health and Medical Research Council and Australian Research Council NUTRITIONAL CHALLENGES OF THE GERIATRIC EQUINE ATHLETE E. Owens. Equine Research Unit, School of Agriculture and Food Sciences, The University of Queensland, Gatton, QLD, Australia