- Email: [email protected]
Talinum triangulare Whole wheat meal fortified with soy flour consumed with Talinum triangulare (gbure) soup glycemic index and the test human subjects' lipid profiles
G Model DSX 853 No. of Pages 7
Diabetes & Metabolic Syndrome: Clinical Research & Reviews xxx (2017) xxx–xxx
Contents lists available at ScienceDirect
Diabetes & Metabolic Syndrome: Clinical Research & Reviews journal homepage: www.elsevier.com/locate/dsx
Original Article
Talinum triangulare Whole wheat meal fortified with soy flour consumed with Talinum triangulare (gbure) soup glycemic index and the test human subjects' lipid profiles Sunday Adeola Emaleku* , Olusola D. Omueti, Godsent Oluwakemi Emaleku Biochemistry Department, Adekunle Ajasin University, Akungba Akoko, Ondo State, Nigeria
A R T I C L E I N F O
A B S T R A C T
Article history: Available online xxx
Aim: Cardiovascular diseases (CVDs) and diabetes mellitus (DM) are some of the leading causes of death in the world, and diet has roles in their etiology. This research study therefore investigates the glycemic index (GI) of soy flour fortified whole wheat meal (SFFWWM) consumed with Talinum triangulare (gbure) soup and the effects of the meal on the lipid profiles of the test human subjects. Methods: The control human subjects and test human subjects were fed D-glucose (DG) and whole wheat meal (WWM) with Talinum triangulare soup respectively on the first day of the experiment, and SFFWWM with the same soup the next day (for test subjects only) after 10–12 h overnight fasting. Blood glucose levels of the subjects were taken before and 2 h after meals’ consumption at 30 min interval and blood samples collected for lipid profiles evaluations. Results: The result of the study showed that; SFFWWM consumed with Talinum trianguilare soup has a non-significant lower GI than WWM consumed with the same soup, but a significant lower GI than DG at (P < 0.05). Furthermore, there was no significant difference in lipid profiles of the test human subjects between when they consumed WWM and SFFWWM with the soup however, SFFWWM reduced TC, TG, LDL-C and VDL-C and increased HDL-C and TP than WMM at (P < 0.05). In addition, GI is positively correlated with TC, TG, LDL-C and VLDL-C, but is negatively correlated with TP and HDL-C. Conclusion: It can therefore be concluded that; fortifying WWM with soy flour would reduce the risk factors of CVDs and DM, the diseases recently claiming thousands of today. © 2017 Diabetes India. Published by Elsevier Ltd. All rights reserved.
Keywords: Cardiovascular diseases Diabetes mellitus Soy flour Diet Glycemic index
1. Introduction Cardiovascular diseases (CVDs) such as heart attack, stroke, hypertension etc and diabetes mellitus (DM) are some of the leading causes of death in the world today [1]. Diet makes the increase in incidence and prevalence of these non-communicable diseases (NCDs) to be less difficult to control globally, most especially in Nigeria. According to Feskens et al. [2], malnutrition has an etiology in the rise as well as occurrence of these diseases, and hence they are commonly called nutritional diseases or nutritional disorders. In fact, diet has a major impact on several modifiable risk factors for these nutritional diseases. Thus, food consumed for sustenance, growth and development of the body has suddenly become the road map to early grave for mankind [1].
* Corresponding author. E-mail addresses: [email protected], [email protected], [email protected], [email protected] (S.A. Emaleku).
It is therefore expedient for human population to critically examine what they eat and be very selective in their choice of foods. In this examination, the aspect of glycemic index, lipid profiles, nutritive values and therapeutic effects of commonly consumed foods in relation to human health should be of great importance, so as to minimize if not totally eradicate the incidence and prevalence of these NCDs [3]. It is this drive and passion that brought this research study into limelight: “Whole wheat meal fortified with soy flour consumed with Talinum triangulare soup glycemic index and the test human subjects' lipid profiles”. Wheat, from which whole wheat meal was processed (i.e. all the kernel parts such as bran, endosperm and germ are present) [4], is a major staple food in Nigeria and one of the cheapest sources of protein and calories [5]. Its main dietary contributions are carbohydrate, but besides this, it also provides protein and a small amount of lipids, fibers and vitamins. However, when fortified with soy flour, which is richer in proteins, essential fatty acids, fibers, vitamins and minerals, its nutritional qualities would certainly be improved. Its low protein content and limited
https://doi.org/10.1016/j.dsx.2017.08.007 1871-4021/© 2017 Diabetes India. Published by Elsevier Ltd. All rights reserved.
Please cite this article in press as: S.A. Emaleku, et al., Talinum triangulare Whole wheat meal fortified with soy flour consumed with Talinum triangulare (gbure) soup glycemic index and the test human subjects’ lipid profiles, Diab Met Syndr: Clin Res Rev (2017), http://dx.doi.org/ 10.1016/j.dsx.2017.08.007
G Model DSX 853 No. of Pages 7
2
S.A. Emaleku et al. / Diabetes & Metabolic Syndrome: Clinical Research & Reviews xxx (2017) xxx–xxx
biological protein quality that is highly deficient in lysine and tryptophan, which are its main nutritional drawbacks [6,7] should no longer be an issue. Hence, the aim of this research study is therefore to investigate the glycemic index of whole wheat meal fortified with soy flour consumed with Talinum triangulare (gbure) soup and the lipid profiles of the test human subjects. 2. Subjects, materials and methods 2.1. Experimental subjects Six human subjects consisting of both sexes were selected from faculty of science departments of Adekunle Ajasin University, Akungba-Akoko, Ondo State, Nigeria, after permission had been obtained from the University’s Health Centre (UHC), and the World Medical Association (WMA) declaration of Helsinki ethical principles for medical research involving human subjects was duly observed. The interest and consent of the subjects were verbally sought. They were clinically normal, non-smokers, nonalcoholics, non-hyperlipidemia and non-diabetic subjects, and were divided into two groups of threes (control and test groups). Both groups followed the study protocols (rules) without any prejudice to their social and religious status, and remained within the confinement of the experimental area. 2.2. Food stuff Fresh green sample of Talinum triangulare (gbure) vegetable was purchased at Ibaka-Akungba local market, Ondo State, Nigeria and was identified and authenticated by Dr. O.A. Obembe, a senior lecturer in the department of Plant Science and Biotechnology of Adekunle Ajasin University, Akungba Akoko, Ondo State, while Honey well whole wheat meal and large seeded variety of soy bean (Glycine max), with creamy colour were purchased from Bodija market at Ibadan, Oyo State, and were certified hygienic for human consumption. 2.3. Food stuff preparation The fresh green leafy vegetable, whose edible portion has been separated from its inedible parts, was rinsed in clean water, allowed to drain and subsequently shredded into slices of almost equal sizes. 170 g was weighed and cooked for the 3 test subjects using 100 g of palm oil, 10 ml of water with some condiments (i.e. 55 g onion, 127 g pepper (atarodo), 2 known-chicken maggi cubes) and little quantity of table salt was added. It steamed for about 10– 13 min before it was removed from the stove. Soy bean was processed into soy flour using Omueti and Morton [8] processing method. The soy flour was then used to fortify Honey well whole wheat meal using fortification ratio of 1:3 respectively. The mixture quantity containing 50 g available carbohydrate was prepared into solid paste for consumption with Talinum triangulare (gbure) soup by each of the test subjects. Similarly, whole wheat meal quantity containing 50 g available carbohydrate was also prepared into solid paste for consumption with Talinum triangulare (gbure) soup by each of the test subjects,
while 50 g of D-glucose was dissolved in 100 ml of water for each of the control subjects. 2.4. Feeding of human subjects After 10–12 h of overnight fasting, the control group that served as reference point or standard for the test group was fed 100 ml water-dissolved glucose each for one day i.e. the first day of the experiment, while the test group was fed WWM and SFFWWM consumed with Talinum triangulare (gbure) soup for first and second day of the experiment respectively i.e. for two experimental days. 2.5. Blood glucose determination The pre and postprandial blood glucose, i.e. fasting blood sugar (FBS) and random blood sugar (RBS) respectively of the human subjects were determined once before meals and four times for two hours at 30 min intervals after meals using glucometer.
2.6. Blood sample collection 3 ml of venous blood sample was collected before and 5 h after meals from each of the test human subjects and these blood samples were used for lipid profile assay of the human subjects.
2.7. Glycemic index determination A modified version of Wolever et al. [9] method was used to determine the glycemic index (GI) of each meal type (WWM and SFFWWM consumed with Talinum triangulare soup) from the plotted mean blood glucose response curve graph (Fig. 4). The mean of the pre and postprandial blood glucose of the subjects were then used to determine the incremental areas under the curves (IUAC) of the various meal types (DG, WWM and SFFWWM). IAUC was gotten by summing up the surface triangles and rectangles under the blood glucose response curve. The GI of the test meals was then gotten by dividing the IAUC of the test meals (e.g. WWM or SFFWWM) by IUAC of the standard meal (DG) multiply by 100. For example, GI = IUAC of WWM IUAC of standard (glucose) 100% 2.8. Lipid profile assays (Estimation of biomolecules) Lipid profile parameters such as total cholesterol (TC), triglyceride, high density lipoprotein-cholesterol (HDL-C), low density lipoprotein-cholesterol (LDL-C) and total protein (TP) were determined by enzymatic end point method using randox kits. However, very low density lipoproteins cholesterol (VLDL-C) was calculated using the below formula. VLDL-C = TRIG/5
Table 1 Proximate Analyses of Food Samples. SAMPLE ID
%MOISTURE
%CRUDE PROTEIN
%CRUDE FAT
%CRUDE FIBER
%ASH
%NFE
SAMPLE A SAMPLE B SAMPLE C
11.20 9.75 7.00
13.86 22.83 50.91
2.87 6.28 25.84
2.61 4.31 3.27
1.73 1.95 2.47
67.73 54.88 10.51
Key: Sample A- Whole Wheat Meal; Sample B- Soy Flour Fortified Whole Wheat Meal; Sample C- Soy Flour, NFE- Nitrogen Free Extract.
Please cite this article in press as: S.A. Emaleku, et al., Talinum triangulare Whole wheat meal fortified with soy flour consumed with Talinum triangulare (gbure) soup glycemic index and the test human subjects’ lipid profiles, Diab Met Syndr: Clin Res Rev (2017), http://dx.doi.org/ 10.1016/j.dsx.2017.08.007
G Model DSX 853 No. of Pages 7
S.A. Emaleku et al. / Diabetes & Metabolic Syndrome: Clinical Research & Reviews xxx (2017) xxx–xxx Table 2 Glycemic Index of Consumed Meals. MEAL TYPES
GI VALUES (%)
LSD
DG WWM SFFWWM
100.00 A 0.00 55.00 B 11.93 41.00 B 8.39
24.24 24.24 24.24
NOTE: These results are presented in mean standard error mean (SEM). At (p < 0.05) significance, values with the same notations do not differ significantly but those with different notations do. KEY: DG = D-Glucose, WWM = Whole wheat meal, SFFWWM = Soy flour fortified whole wheat meal, LSD = Least significance difference.
2.9. Statistical analysis The GI and lipid profiles data were statistically evaluated with SAS version 8 software using one-way analysis of variance (ANOVA) with Duncan Multiple Range Test, T-test and Pearson Correlation, and the results were expressed as mean standard error mean (SEM). F-test and T- test at 95% (i.e. 0.05) level of significance was used to assess significant difference. A value of P < 0.05 was considered to indicate significant difference between groups. 3. Results Table 1 result revealed that; whole wheat meal (WWM) had the highest nitrogen free extract (NFE) content (67.73%) and moisture content (11.20%), and moderately good crude protein content (13.86%), but low (i.e. the lowest) crude fat (2.87%) and crude fiber (2.61%), while soy flour (SF) had the least NFE value (10.51%) and moisture content (7.00%), but had the highest crude protein content (50.91%) and crude fat (25.84%) and as well possessed a fairly good contents of crude fiber (3.27%) and ash (2.47%). The
3
result further showed that; soy flour fortified whole wheat meal (SFFWWM) had moderate and improved nutritional contents in comparison with WWM (i.e. above average NFE value (54.88%) and a better crude protein (22.83%), crude fat (6.28%), crude fiber (4.31%), ash (1.95%) contents, but a lesser moisture content (9.75%). Table 2 results showed that; the test meals had significantly lesser GIs (WWM consumed with Talinum triangulare soup 55% and SFFWWM consumed with Talinum triangulare soup 41%) than the control meal’s DG) GI (100%), but the GIs of the test meals did not differ significantly from each other at (P < 0.05) however, SFFWWM consumed with Talinum triangulare soup had a lower GI (41%) than WWM consumed with Talinum triangulare soup (55%). Figs. 1–4 showed that; the test meals (SFFWWM and WWM consumed with Talinum triangulare soup), most especially SFFWWM caused lesser incremental area under curve (IAUC) 2 h after consumption when compared with DG. In other words, they caused a lesser spike (little increase) in blood glucose levels of the subjects than the control meal (DG) nevertheless; SFFWWM consumed with Talinum triangulare soup blood glucose spike is the least. Considering For Fig. 4 for example, SFFWWM consumed with Talinum triangulare soup increased blood glucose levels of subjects’ slightly by 1 mg/dl, WWM consumed with Talinum triangulare soup increased by 5 mg/dl, while DG increased by 44 mg/dl 30 min after consumption. This is in consistent with the findings of Wolever et al. [9] and Freeman [10] on low and high GI foods. It is also in line with Brand-Miller et al. [11] findings about blood glucose response curves for low and high foods. Table 3 result showed that GI has a positive, but non-significant correlation with CVDs risk factors (TC, TG, LDL-C and VLDL-C) and a negative, significant correlation with HDL-C, but a negative nonsignificant correlation with TP (both of which are heart-healthy benefiting factors).
Fig. 1. Subject A blood glucose response curve for D-Glucose, Whole wheat meal and Soy fortification.
Please cite this article in press as: S.A. Emaleku, et al., Talinum triangulare Whole wheat meal fortified with soy flour consumed with Talinum triangulare (gbure) soup glycemic index and the test human subjects’ lipid profiles, Diab Met Syndr: Clin Res Rev (2017), http://dx.doi.org/ 10.1016/j.dsx.2017.08.007
G Model DSX 853 No. of Pages 7
4
S.A. Emaleku et al. / Diabetes & Metabolic Syndrome: Clinical Research & Reviews xxx (2017) xxx–xxx
Considering the magnitude of changes in lipid profiles of subjects after meals’ consumption, Table 4 revealed that there was no significant difference in lipid profiles CVDs risk factors (TC, TG, LDL-C & VLDL-C) and healthy-heart benefiting factors (HDL-C & TP) between when the test human subjects consumed WWM and SFFWWM with Talinum triangulare soup. However, SFFWWM consumed with Talinum triangulare soup slightly reduced TC (164.67-163.00 mg/dl), TG (87.67-85.33 mg/dl), LDL-C (68.6767.33 mg/dl), VLDL-C (17.67-17.00 mg/dl) by 1.67 mg/dl, 2.33 mg/dl, 1.33 mg/dl and 0.67 mg/dl respectively and slightly increased HDL-C (77.33-79.00 mg/dl) by 1.67 mg/dl and TP (51.67-59.67 mg/dl) by 8.00 mg/dl conversely, WWM consumed with Talinum triangulare soup increased slightly TC (151.33154.00 mg/dl), TG (86.67-89.00 mg/dl), LDL-C (64.67-68.67 mg/ dl), VLDL-C (17.33-18.00 mg/dl) and TP (44.67-50.33 mg/dl) by 2.67 mg/dl, 2.33 mg/dl, 4.00 mg/dl, 0.67 mg/dl, 5.67 mg/dl respectively, but reduced HDL-C (77.67-76.67 mg/dl) slightly by 1.00 mg/dl. These results are similar to the findings of Zhan and Ho [12] and Anderson et al. [13]. 4. Discussion WWM processed from unrefined wheat (whole wheat grain), has its germ, endosperm and bran (collectively called whole kernel) intact unlike the refined wheat, which retains only the endosperm that is made up of mainly carbohydrate. This reason accounts for the higher nitrogen free extract (79%) Jenkins et al. [14] reported for white flour, refined wheat made solely from endosperm in comparison with ours (67.73%). WWM germ is rich in protein, vitamin Bs and omega 3 and 6 fatty acids and its bran rich in crude fiber, iron and vitamin Bs [4,15,16] and these could be
adduced for its moderately good protein content and a fairly good amount of crude fat and crude fiber content. Schwartz [15] reported that WWM contained omega 3 (a-linolenic acid) and 6 (linoleic acid and g-linolenic acid) fatty acids and a higher fiber percentage than white flour (refined form), whose germ and bran had been removed [4]. Fortification of WWM with soy flour improved crude protein content from 13.86% to 22.83%, crude fat from 2.87% to 6.28%, crude fiber content from 2.61% to 4.31% and ash content from 1.73% to 1.95%, but reduces NFE and moisture contents from 67.73% to 54.80% and 11.20% to 9.75% respectively because; soy flour is considered equivalent to animal protein in quality and as a complete protein, it contains plenty essential amino acids, and also a source of polyunsaturated (linoleic acid and linolenic acid), monounsaturated fatty acids e.g. oleic acid [17,18], and fiber (both soluble and insoluble) [19]. Thus, all these qualities in addition of being an isoflavone helped soy to improve the nutritional content of WWM in SFFWWM as shown by the proximate analysis results. Low GI foods are not quickly digested or metabolized to an extent that shoot up the blood glucose levels rapidly, but are rather slowly digested to gradually release glucose into the blood in a level that would not cause any significant rise in blood glucose level that would consequently create any dramatic spike in insulin levels [20,21], which could lead to insulin resistance (type 2 DM) and excessive weight gain (as in obese person) in a long term [21]. In low GI diet, there is less or moderate insulin secretion and a gradual glucose clearance from the blood stream that would subsequently result in greater satiety and consumption of fewer calories throughout the day [11], which would cause reduction in blood glucose levels and lesser insulin spike than in high GI foods hence, the risk of having DM reduced [21,22].
Fig. 2. Subject B blood glucose response curve for D-Glucose, Whole wheat meal and Soy fortification.
Please cite this article in press as: S.A. Emaleku, et al., Talinum triangulare Whole wheat meal fortified with soy flour consumed with Talinum triangulare (gbure) soup glycemic index and the test human subjects’ lipid profiles, Diab Met Syndr: Clin Res Rev (2017), http://dx.doi.org/ 10.1016/j.dsx.2017.08.007
G Model DSX 853 No. of Pages 7
S.A. Emaleku et al. / Diabetes & Metabolic Syndrome: Clinical Research & Reviews xxx (2017) xxx–xxx
5
Fig. 3. Subject/ C blood glucose response curve for D-Glucose, Whole wheat meal and Soy fortification.
Therefore, the low GI values 55% and 41% of the test meals (WWM and SFFWWM consumed with Talinum triangulare soup) respectively are indication that the test meals would have been metabolized slowly and absorbed gradually, and obviously showed the reason for the lower and lowest blood glucose spike in human subjects respectively in comparison with the control meal (DG) as shown in Figs. 1–4. From Figs. 1–4, it could be deduced that; WWM and SFFWWM consumed with Talinum triangulare soup were moderately and slowly metabolized respectively [4,16] to cause lesser spike (little increase) in blood glucose levels of the subjects in contrast with DG that was rapidly metabolized to quickly release blood glucose into the blood stream to an extent that greatly elevate blood sugar level (high spike) of the human subjects [21,20]. It is then suffice to say that; GI is directly proportional to blood glucose response curve/ IAUC, the higher the GI of a food the higher its blood glucose response curve/IAUC and vice versa, and Table 2 and Figs. 1–4 results affirm this assertion. Therefore, the lesser blood glucose response curves of the test meals in comparison with the control meal re-affirms WWM and SFFWWM consumed with Talinum triangulare soup to be low GI foods and suggests that they could not be risk factors for DM, because there would be little or no elevation of blood glucose that could lead to insulin resistance due to continuous significant spike in insulin levels [11,23]. According to Kiens and Richter [24], increased insulin production as a result of high blood glucose and/or over eating of high GI foods may eventually suppress the synthesis of insulin receptors, which may consequently lead to type 2 diabetes mellitus (DM), and invariably, more carbohydrates will be converted to fats and excess of which may eventually lead to cardiovascular diseases (CVDs) or coronary heart diseases (CHDs) such as heart attack, stroke, hypertension etc.
Furthermore, since GI is positively correlated with CVDs risk factors (TC, TG, LDL-C and VLDL-C) and negatively correlated with HDL-C and TP (heart health benefiting factors), it is therefore logical to say that, the test meals, most especially SFFWWM consumed with Talinum triangulare soup with low GI values would not predispose human to DM and CVDs, but DG with high GI value would do, because excess calories would be deposited (stored) as fat in the adipose tissues, which would consequently increase the risk factors of CVDs, the genesis of CVDs [25]. According to Liu et al. [23], excess carbohydrate from high GI foods would be stored as muscle fat storage, which would eventually increase serum cholesterol levels. Therefore, high GI foods can be said to be a risk factor for DM and CVDs, but low GI foods are not, because low GI foods like the test meals, most especially SFFWWM consumed with Talinum triangulare soup with the GI of 41% would decrease lipid profile risk factors for CVDs, but increase heart health benefiting factors [23,26], and this is in line with past findings of Ludwig [21] and Van Dam et al. [26]. Moreover, since the comparison of human subjects’ lipid profiles between before meals and after meals’ consumption showed that SFFWWM consumed with Talinum triangulare soup reduced lipid profiles CVDs risk factors and increased healthyheart benefiting factors, but WWM consumed with Talinum triangulare soup did not, it then implies that soy fortification of WWM had improved its nutritional qualities in all ramifications (i. e improved protein, essential amino acids, EFAs, fibers, minerals, vitamins contents) than unfortified WWM [27,17,18], which would in turn improve its therapeutical effects in preventing or treating heart related diseases as well as DM. This is an indication that SFFWWM contains health benefiting factors that are therapeutically important than WWM [28,29].
Please cite this article in press as: S.A. Emaleku, et al., Talinum triangulare Whole wheat meal fortified with soy flour consumed with Talinum triangulare (gbure) soup glycemic index and the test human subjects’ lipid profiles, Diab Met Syndr: Clin Res Rev (2017), http://dx.doi.org/ 10.1016/j.dsx.2017.08.007
G Model DSX 853 No. of Pages 7
6
S.A. Emaleku et al. / Diabetes & Metabolic Syndrome: Clinical Research & Reviews xxx (2017) xxx–xxx
Fig. 4. Mean blood glucose response curve of human subjects for D-Glucose, Whole wheat meal and Soy fortification.
According to Zhan and Ho [12], soybean protein in addition to being a complete protein contains other naturally occurring constituents such as isoflavones, fibers and saponins, and these had been reported to have hypolipidemic and anti-diabetic effects, most especially saponins. Anderson et al. [13], reported significant
reductions in TC by 9.3%, LDL-C by 12.9% and TG by 10.5% with a small insignificant increase in HDL-C by 2.4% after the consumption of soy for few days. Therefore, the non-significance difference in the lipid profiles of the test human subjects between when they consumed WWM with Talinum triangulare soup and when they
Table 3 Relationship Between Glycemic Index And Lipid Profiles. PARAMETERS
TC
TG
HDL-C
LDL-C
VLDL-C
TP
GI
TC TG HDL-C LDL-C VLDL-C TP GI
1.00000 0.91854S -0.50474NS 0.89348S 0.90956S -0.41961NS 0.40239NS
0.91854S 1.00000 -0.48396NS 0.92825S 0.99806S -0.69820NS 0.40397NS
-0.50474NS -0.48396NS 1.00000 -0.52591NS -0.51078NS 0.27671NS -0.85314S
0.89348S 0.92825S -0.52591NS 1.00000 0.93445S -0.63929NS 0.37795NS
0.90956S 0.99806S -0.51078NS 0.93445S 1.00000 -0.71824S 0.41566NS
-0.41961NS -0.69820NS 0.27671NS -0.63929NS -0.71824S 1.00000 -0.32996NS
0.40239NS 0.40397NS -0.85314S 0.37795NS 0.41566NS -0.32996NS 1.00000
Note: Comparison is strictly within the same parameter. The superscripts S and NS mean differ significantly and no significant difference respectively, at (p < 0.05).
Table 4 Human Subjects Lipid Profiles Magnitude Changes After Meals’ Consumption. PARAMETERS (mg/dl) MEAL TYPES
TC
TG
HDL-C
LDL-C
VLDL-C
TP
DG WWM SFFWWM LSD
28.67A 8.76 2.67B 4.67 -1.67B 1.86 22.15
17.00A 8.89 2.33BA 1.76 -2.33B 2.60 18.01
-3.00A 5.29 -1.00A 1.53 1.67A 1.86 10.12
28.33A 10.09 4.00B 2.52 -1.33B 3.93 24.13
3.67A 1.76 0.67BA 0.33 -0.67B 0.67 3.29
-2.00B 1.73 5.67A 1.20 8.00A 1.73 4.21
Note: Comparison is strictly within parameters. The results were expressed in mean SEM with LSD. Values with the same superscript location do not differ significantly but those with different superscript do at (P < 0.05) significance.
Please cite this article in press as: S.A. Emaleku, et al., Talinum triangulare Whole wheat meal fortified with soy flour consumed with Talinum triangulare (gbure) soup glycemic index and the test human subjects’ lipid profiles, Diab Met Syndr: Clin Res Rev (2017), http://dx.doi.org/ 10.1016/j.dsx.2017.08.007
G Model DSX 853 No. of Pages 7
S.A. Emaleku et al. / Diabetes & Metabolic Syndrome: Clinical Research & Reviews xxx (2017) xxx–xxx
consumed SFFWWM with Talinum triangulare soup could be attributed to the following reasons: 1. The test human subjects were only fed once and not for a prolong period of time. 2. The ratio 3:1 soy fortification might probably not contain the at least 25 g daily soy protein consumption or 26 mg per gram soy protein that Zhan and Ho [12] found to have therapeutic effects on lipid profiles by reducing the risk factors. 3. The test human subjects might probably have recently used some antibiotic drugs before the commencement of the experiment, which would have killed both the harmful and friendly intestinal bacteria that Setchell et al. [30] and Axelson and Setchell [31] found to be important for isoflavones metabolism into effective equol of higher therapeutic effects. 4. The test human subjects used fall within the normal range lipid profiles values, unlike Law et al. [17] and Messina et al. [18] that used hypercholesterolemic humans and found significant difference, but found no significance difference when hypocholesterolemic adult humans were used. It can then be inferred/concluded that fortifying foods with soy flour like SFFWWM would be a good nutrient/dietary (nutritionaltherapeutical) choice in the prevention, treatment and control of DM and CVDs, since SFFWWM consumed with Talinum triangulare soup has low GI value, and reduced lipid profiles CVDs risk factors, but increased healthy-heart benefiting factors than WWM consumed with Talinum triangulare soup. Conflict of interest None Acknowledgements We so much appreciate the Lord Almighty, for His guidance and protection during this research period. We also thank Dr. O.A. Obembe, a senior lecturer in the department of Plant Science and Biotechnology of Adekunle Ajasin University, Akungba-Akoko (AAUA), Ondo State for his contributions toward the success of this study, most especially in identifying the food samples. The assistance of Dr. A.O. Olusola, the amiable incumbent Head of Department of Biochemistry Department, AAUA and Dr. J.A. Saliu cannot be forgotten in a hurry. We deeply acknowledge the support and cooperation of our families that spur us into action for speedy completion of this study. God bless you all, thank you all. References [1] Slavin JL, Lampe J, Hutchins AM, Karr SC. Correlation between dietary glycemic index and cardiovascular disease risk factors among Japanese women. Eur J Clin Nutr 1997;58:1472–8. [2] Feskens EJ, Du H, Anthony M, David BM. Dietary glycemic index from an epidemiological point of view. Int J Obes (Lond) 2006;30(suppl. 3):66–71. [3] Jenkins DJ, Wolever TM, Collier GR, Ocana A, Rao AV, Buckley G, et al. Metabolic effects of a low-glycemic index diet. Am J Clin Nutr 1981;46:968–75.
7
[4] Piperno D. Processing of wild cereal grains in the upper Palaeolithic revealed by starch grain analysis. Nat J 2004;430(70):670–3. [5] USDA National Nutrient Database for Standard Reference. United States Department of Agriculture; 2003. [6] Ortega LE, Villegas E, Vasal KS. A comparative study of protein changes in normal and quality protein maize during tortilla making. Cereal Chem 1986;63:446–51. [7] Waliszewski NK, Estrada Y, Parido V. Lysine and tryptophan fortification of nixtamalized corn flour. Int J Food Sci Nutr 2000;80:237–42. [8] Omueti O, Morton O. Development, acceptability, nutritional and physical characteristics of protein improved Nigerian abari (maize meal) prepared from soya and maize flours. Int J Food Sci Nutr 1996;47:369–75. [9] Wolever TM, Jenkins DJ, Jenkins AL, Josse RG. The glycemic index: Methodology and clinical implications. Am J Clin Nutr 1991;54:846–54. [10] Freeman H. Slowly digested and absorbed carbohydrate in traditional bush foods: a protective factor against diabetes. Diab Care 2005;321:436–43. [11] Brand-Miller JC, Holt SH, Pawlak DB, McMillan J. Glycemic index and obesity. Am J Clin Nutr 2005;76:281–5. [12] Zhan S, Ho SC. Meta-analysis of the effects of soy protein containing isoflavones on the lipid profiles. Am J Clin Nutr 2005;81:397–408. [13] Anderson JW, Bryan MD, Johnstone M, Cook-Newell ME. Meta-Analysis of the effect of soy protein intake in serum. N Engl J Med 1995;333:276–82. [14] Jenkins DJA, Kendall CWC, Jackson CC, Connelly PW, Parker FDT, Vidgen E, et al. Effects of high and low isoflavone soy foods on blood lipids, oxidized LDL, homocysteine, and blood pressure in hyperlipidemic men and women. Am J Clin Nutr 2008;76:365–72. [15] R Schwartz, A whole grain of truth: The authoritative guide to the glycemic index and the dietary solution for lifelong health. [16] Wikipedia Wholegrain intake is favorably associated with metabolic risk factors for type 2 diabetes and cardiovascular disease in the Framingham Offspring Study, (2009). [17] M R Law, N J Wald, S G Thompson, By how much and how quickly does reduction in serum cholesterol concentration lower risk of ischemic heart disease? (1994) 308: 367–372. [18] Messina M, Lane B, Setchell KV. Soy protein, soybean isoflavones, and coronary heart disease risk. Fut Lipidol 1994;2:55–74. [19] Gupta Y. Nutritive value of soy bean. Int J Trop Agric 1987;3:15–23. [20] Allan A. Grains industry trends in production-results from today’s farming practices. Grains Council of Australia Limited; 2006. p. 18–27. [21] Ludwig DS. Glycemic index: physiological mechanisms relating to obesity, diabetes and cardiovascular diseases. JAMA 2002;287:2414–23. [22] Sheard NF, Clark NG, Brand-Miller JC. Dietary carbohydrate (amount and type) in the prevention and management of diabetes: a statement by the American diabetes association. 2004. [23] Liu S, Manson JE, Buring JE, Stampfer MJ, Willett WC, Ridker PM. Relation between a diet with a high glycemic load and plasma concentrations of highsensitivity C-reactive protein in middle-aged women. Am J Clin Nutr 2000;75:492–8. [24] Kiens JF, Ritcher TM. Correlation between dietary glycemic index and cardiovascular disease risk factors among Japanese women. Eur J Clin Nutr 1996;58:1472–8. [25] Uchiki T, Weikel KA, Jiao W. Glycation-altered proteolysis as a pathobiologic mechanism that links dietary glycemic index, aging, and age-related disease in non-diabetics. Aging Cell 2012;11(1):1–13. [26] Van Dam RM, Visscher AW, Feskens EJ, Verhoef P, Kromhout D. Dietary glycemic index in relation to metabolic risk factors and incidence of coronary heart diseases. Eur J Clin Nutr 2000;54:726–31. [27] Lokesh JC, Reynolds K, Chin A, Lees KA, Nguyen A, Bujnowski D, et al. A Metaanalysis of the effect of soy protein supplementation on serum lipids. Am J Cardiol 2004;98(5):633–40. [28] Ali MB. Characteristics and production cost of US wheat farms. ERS Press, USDA; 2002. p. 974–5. [29] Riaz MN. Soy applications in foods. Boca Raton, FL: CRC Press; 2006. p. 493–8. [30] Setchell KDR, Brown NM, Desai P, Zimmer-Nechemias L, Wolfe BE, Brashear WT, et al. Bioavailability of pure isoflavones in healthy humans and analysis of commercial soy isoflavone. J Nutr 1997;131(1):1362–75. [31] Axelson M, setchell KDR. The excretion of lignans in rats: evidence for an intestinal bacterial source for this new group of compounds. FEBS Lett 1981;37–45.
Please cite this article in press as: S.A. Emaleku, et al., Talinum triangulare Whole wheat meal fortified with soy flour consumed with Talinum triangulare (gbure) soup glycemic index and the test human subjects’ lipid profiles, Diab Met Syndr: Clin Res Rev (2017), http://dx.doi.org/ 10.1016/j.dsx.2017.08.007
Diabetes & Metabolic Syndrome: Clinical Research & Reviews xxx (2017) xxx–xxx
Contents lists available at ScienceDirect
Diabetes & Metabolic Syndrome: Clinical Research & Reviews journal homepage: www.elsevier.com/locate/dsx
Original Article
Talinum triangulare Whole wheat meal fortified with soy flour consumed with Talinum triangulare (gbure) soup glycemic index and the test human subjects' lipid profiles Sunday Adeola Emaleku* , Olusola D. Omueti, Godsent Oluwakemi Emaleku Biochemistry Department, Adekunle Ajasin University, Akungba Akoko, Ondo State, Nigeria
A R T I C L E I N F O
A B S T R A C T
Article history: Available online xxx
Aim: Cardiovascular diseases (CVDs) and diabetes mellitus (DM) are some of the leading causes of death in the world, and diet has roles in their etiology. This research study therefore investigates the glycemic index (GI) of soy flour fortified whole wheat meal (SFFWWM) consumed with Talinum triangulare (gbure) soup and the effects of the meal on the lipid profiles of the test human subjects. Methods: The control human subjects and test human subjects were fed D-glucose (DG) and whole wheat meal (WWM) with Talinum triangulare soup respectively on the first day of the experiment, and SFFWWM with the same soup the next day (for test subjects only) after 10–12 h overnight fasting. Blood glucose levels of the subjects were taken before and 2 h after meals’ consumption at 30 min interval and blood samples collected for lipid profiles evaluations. Results: The result of the study showed that; SFFWWM consumed with Talinum trianguilare soup has a non-significant lower GI than WWM consumed with the same soup, but a significant lower GI than DG at (P < 0.05). Furthermore, there was no significant difference in lipid profiles of the test human subjects between when they consumed WWM and SFFWWM with the soup however, SFFWWM reduced TC, TG, LDL-C and VDL-C and increased HDL-C and TP than WMM at (P < 0.05). In addition, GI is positively correlated with TC, TG, LDL-C and VLDL-C, but is negatively correlated with TP and HDL-C. Conclusion: It can therefore be concluded that; fortifying WWM with soy flour would reduce the risk factors of CVDs and DM, the diseases recently claiming thousands of today. © 2017 Diabetes India. Published by Elsevier Ltd. All rights reserved.
Keywords: Cardiovascular diseases Diabetes mellitus Soy flour Diet Glycemic index
1. Introduction Cardiovascular diseases (CVDs) such as heart attack, stroke, hypertension etc and diabetes mellitus (DM) are some of the leading causes of death in the world today [1]. Diet makes the increase in incidence and prevalence of these non-communicable diseases (NCDs) to be less difficult to control globally, most especially in Nigeria. According to Feskens et al. [2], malnutrition has an etiology in the rise as well as occurrence of these diseases, and hence they are commonly called nutritional diseases or nutritional disorders. In fact, diet has a major impact on several modifiable risk factors for these nutritional diseases. Thus, food consumed for sustenance, growth and development of the body has suddenly become the road map to early grave for mankind [1].
* Corresponding author. E-mail addresses: [email protected], [email protected], [email protected], [email protected] (S.A. Emaleku).
It is therefore expedient for human population to critically examine what they eat and be very selective in their choice of foods. In this examination, the aspect of glycemic index, lipid profiles, nutritive values and therapeutic effects of commonly consumed foods in relation to human health should be of great importance, so as to minimize if not totally eradicate the incidence and prevalence of these NCDs [3]. It is this drive and passion that brought this research study into limelight: “Whole wheat meal fortified with soy flour consumed with Talinum triangulare soup glycemic index and the test human subjects' lipid profiles”. Wheat, from which whole wheat meal was processed (i.e. all the kernel parts such as bran, endosperm and germ are present) [4], is a major staple food in Nigeria and one of the cheapest sources of protein and calories [5]. Its main dietary contributions are carbohydrate, but besides this, it also provides protein and a small amount of lipids, fibers and vitamins. However, when fortified with soy flour, which is richer in proteins, essential fatty acids, fibers, vitamins and minerals, its nutritional qualities would certainly be improved. Its low protein content and limited
https://doi.org/10.1016/j.dsx.2017.08.007 1871-4021/© 2017 Diabetes India. Published by Elsevier Ltd. All rights reserved.
Please cite this article in press as: S.A. Emaleku, et al., Talinum triangulare Whole wheat meal fortified with soy flour consumed with Talinum triangulare (gbure) soup glycemic index and the test human subjects’ lipid profiles, Diab Met Syndr: Clin Res Rev (2017), http://dx.doi.org/ 10.1016/j.dsx.2017.08.007
G Model DSX 853 No. of Pages 7
2
S.A. Emaleku et al. / Diabetes & Metabolic Syndrome: Clinical Research & Reviews xxx (2017) xxx–xxx
biological protein quality that is highly deficient in lysine and tryptophan, which are its main nutritional drawbacks [6,7] should no longer be an issue. Hence, the aim of this research study is therefore to investigate the glycemic index of whole wheat meal fortified with soy flour consumed with Talinum triangulare (gbure) soup and the lipid profiles of the test human subjects. 2. Subjects, materials and methods 2.1. Experimental subjects Six human subjects consisting of both sexes were selected from faculty of science departments of Adekunle Ajasin University, Akungba-Akoko, Ondo State, Nigeria, after permission had been obtained from the University’s Health Centre (UHC), and the World Medical Association (WMA) declaration of Helsinki ethical principles for medical research involving human subjects was duly observed. The interest and consent of the subjects were verbally sought. They were clinically normal, non-smokers, nonalcoholics, non-hyperlipidemia and non-diabetic subjects, and were divided into two groups of threes (control and test groups). Both groups followed the study protocols (rules) without any prejudice to their social and religious status, and remained within the confinement of the experimental area. 2.2. Food stuff Fresh green sample of Talinum triangulare (gbure) vegetable was purchased at Ibaka-Akungba local market, Ondo State, Nigeria and was identified and authenticated by Dr. O.A. Obembe, a senior lecturer in the department of Plant Science and Biotechnology of Adekunle Ajasin University, Akungba Akoko, Ondo State, while Honey well whole wheat meal and large seeded variety of soy bean (Glycine max), with creamy colour were purchased from Bodija market at Ibadan, Oyo State, and were certified hygienic for human consumption. 2.3. Food stuff preparation The fresh green leafy vegetable, whose edible portion has been separated from its inedible parts, was rinsed in clean water, allowed to drain and subsequently shredded into slices of almost equal sizes. 170 g was weighed and cooked for the 3 test subjects using 100 g of palm oil, 10 ml of water with some condiments (i.e. 55 g onion, 127 g pepper (atarodo), 2 known-chicken maggi cubes) and little quantity of table salt was added. It steamed for about 10– 13 min before it was removed from the stove. Soy bean was processed into soy flour using Omueti and Morton [8] processing method. The soy flour was then used to fortify Honey well whole wheat meal using fortification ratio of 1:3 respectively. The mixture quantity containing 50 g available carbohydrate was prepared into solid paste for consumption with Talinum triangulare (gbure) soup by each of the test subjects. Similarly, whole wheat meal quantity containing 50 g available carbohydrate was also prepared into solid paste for consumption with Talinum triangulare (gbure) soup by each of the test subjects,
while 50 g of D-glucose was dissolved in 100 ml of water for each of the control subjects. 2.4. Feeding of human subjects After 10–12 h of overnight fasting, the control group that served as reference point or standard for the test group was fed 100 ml water-dissolved glucose each for one day i.e. the first day of the experiment, while the test group was fed WWM and SFFWWM consumed with Talinum triangulare (gbure) soup for first and second day of the experiment respectively i.e. for two experimental days. 2.5. Blood glucose determination The pre and postprandial blood glucose, i.e. fasting blood sugar (FBS) and random blood sugar (RBS) respectively of the human subjects were determined once before meals and four times for two hours at 30 min intervals after meals using glucometer.
2.6. Blood sample collection 3 ml of venous blood sample was collected before and 5 h after meals from each of the test human subjects and these blood samples were used for lipid profile assay of the human subjects.
2.7. Glycemic index determination A modified version of Wolever et al. [9] method was used to determine the glycemic index (GI) of each meal type (WWM and SFFWWM consumed with Talinum triangulare soup) from the plotted mean blood glucose response curve graph (Fig. 4). The mean of the pre and postprandial blood glucose of the subjects were then used to determine the incremental areas under the curves (IUAC) of the various meal types (DG, WWM and SFFWWM). IAUC was gotten by summing up the surface triangles and rectangles under the blood glucose response curve. The GI of the test meals was then gotten by dividing the IAUC of the test meals (e.g. WWM or SFFWWM) by IUAC of the standard meal (DG) multiply by 100. For example, GI = IUAC of WWM IUAC of standard (glucose) 100% 2.8. Lipid profile assays (Estimation of biomolecules) Lipid profile parameters such as total cholesterol (TC), triglyceride, high density lipoprotein-cholesterol (HDL-C), low density lipoprotein-cholesterol (LDL-C) and total protein (TP) were determined by enzymatic end point method using randox kits. However, very low density lipoproteins cholesterol (VLDL-C) was calculated using the below formula. VLDL-C = TRIG/5
Table 1 Proximate Analyses of Food Samples. SAMPLE ID
%MOISTURE
%CRUDE PROTEIN
%CRUDE FAT
%CRUDE FIBER
%ASH
%NFE
SAMPLE A SAMPLE B SAMPLE C
11.20 9.75 7.00
13.86 22.83 50.91
2.87 6.28 25.84
2.61 4.31 3.27
1.73 1.95 2.47
67.73 54.88 10.51
Key: Sample A- Whole Wheat Meal; Sample B- Soy Flour Fortified Whole Wheat Meal; Sample C- Soy Flour, NFE- Nitrogen Free Extract.
Please cite this article in press as: S.A. Emaleku, et al., Talinum triangulare Whole wheat meal fortified with soy flour consumed with Talinum triangulare (gbure) soup glycemic index and the test human subjects’ lipid profiles, Diab Met Syndr: Clin Res Rev (2017), http://dx.doi.org/ 10.1016/j.dsx.2017.08.007
G Model DSX 853 No. of Pages 7
S.A. Emaleku et al. / Diabetes & Metabolic Syndrome: Clinical Research & Reviews xxx (2017) xxx–xxx Table 2 Glycemic Index of Consumed Meals. MEAL TYPES
GI VALUES (%)
LSD
DG WWM SFFWWM
100.00 A 0.00 55.00 B 11.93 41.00 B 8.39
24.24 24.24 24.24
NOTE: These results are presented in mean standard error mean (SEM). At (p < 0.05) significance, values with the same notations do not differ significantly but those with different notations do. KEY: DG = D-Glucose, WWM = Whole wheat meal, SFFWWM = Soy flour fortified whole wheat meal, LSD = Least significance difference.
2.9. Statistical analysis The GI and lipid profiles data were statistically evaluated with SAS version 8 software using one-way analysis of variance (ANOVA) with Duncan Multiple Range Test, T-test and Pearson Correlation, and the results were expressed as mean standard error mean (SEM). F-test and T- test at 95% (i.e. 0.05) level of significance was used to assess significant difference. A value of P < 0.05 was considered to indicate significant difference between groups. 3. Results Table 1 result revealed that; whole wheat meal (WWM) had the highest nitrogen free extract (NFE) content (67.73%) and moisture content (11.20%), and moderately good crude protein content (13.86%), but low (i.e. the lowest) crude fat (2.87%) and crude fiber (2.61%), while soy flour (SF) had the least NFE value (10.51%) and moisture content (7.00%), but had the highest crude protein content (50.91%) and crude fat (25.84%) and as well possessed a fairly good contents of crude fiber (3.27%) and ash (2.47%). The
3
result further showed that; soy flour fortified whole wheat meal (SFFWWM) had moderate and improved nutritional contents in comparison with WWM (i.e. above average NFE value (54.88%) and a better crude protein (22.83%), crude fat (6.28%), crude fiber (4.31%), ash (1.95%) contents, but a lesser moisture content (9.75%). Table 2 results showed that; the test meals had significantly lesser GIs (WWM consumed with Talinum triangulare soup 55% and SFFWWM consumed with Talinum triangulare soup 41%) than the control meal’s DG) GI (100%), but the GIs of the test meals did not differ significantly from each other at (P < 0.05) however, SFFWWM consumed with Talinum triangulare soup had a lower GI (41%) than WWM consumed with Talinum triangulare soup (55%). Figs. 1–4 showed that; the test meals (SFFWWM and WWM consumed with Talinum triangulare soup), most especially SFFWWM caused lesser incremental area under curve (IAUC) 2 h after consumption when compared with DG. In other words, they caused a lesser spike (little increase) in blood glucose levels of the subjects than the control meal (DG) nevertheless; SFFWWM consumed with Talinum triangulare soup blood glucose spike is the least. Considering For Fig. 4 for example, SFFWWM consumed with Talinum triangulare soup increased blood glucose levels of subjects’ slightly by 1 mg/dl, WWM consumed with Talinum triangulare soup increased by 5 mg/dl, while DG increased by 44 mg/dl 30 min after consumption. This is in consistent with the findings of Wolever et al. [9] and Freeman [10] on low and high GI foods. It is also in line with Brand-Miller et al. [11] findings about blood glucose response curves for low and high foods. Table 3 result showed that GI has a positive, but non-significant correlation with CVDs risk factors (TC, TG, LDL-C and VLDL-C) and a negative, significant correlation with HDL-C, but a negative nonsignificant correlation with TP (both of which are heart-healthy benefiting factors).
Fig. 1. Subject A blood glucose response curve for D-Glucose, Whole wheat meal and Soy fortification.
Please cite this article in press as: S.A. Emaleku, et al., Talinum triangulare Whole wheat meal fortified with soy flour consumed with Talinum triangulare (gbure) soup glycemic index and the test human subjects’ lipid profiles, Diab Met Syndr: Clin Res Rev (2017), http://dx.doi.org/ 10.1016/j.dsx.2017.08.007
G Model DSX 853 No. of Pages 7
4
S.A. Emaleku et al. / Diabetes & Metabolic Syndrome: Clinical Research & Reviews xxx (2017) xxx–xxx
Considering the magnitude of changes in lipid profiles of subjects after meals’ consumption, Table 4 revealed that there was no significant difference in lipid profiles CVDs risk factors (TC, TG, LDL-C & VLDL-C) and healthy-heart benefiting factors (HDL-C & TP) between when the test human subjects consumed WWM and SFFWWM with Talinum triangulare soup. However, SFFWWM consumed with Talinum triangulare soup slightly reduced TC (164.67-163.00 mg/dl), TG (87.67-85.33 mg/dl), LDL-C (68.6767.33 mg/dl), VLDL-C (17.67-17.00 mg/dl) by 1.67 mg/dl, 2.33 mg/dl, 1.33 mg/dl and 0.67 mg/dl respectively and slightly increased HDL-C (77.33-79.00 mg/dl) by 1.67 mg/dl and TP (51.67-59.67 mg/dl) by 8.00 mg/dl conversely, WWM consumed with Talinum triangulare soup increased slightly TC (151.33154.00 mg/dl), TG (86.67-89.00 mg/dl), LDL-C (64.67-68.67 mg/ dl), VLDL-C (17.33-18.00 mg/dl) and TP (44.67-50.33 mg/dl) by 2.67 mg/dl, 2.33 mg/dl, 4.00 mg/dl, 0.67 mg/dl, 5.67 mg/dl respectively, but reduced HDL-C (77.67-76.67 mg/dl) slightly by 1.00 mg/dl. These results are similar to the findings of Zhan and Ho [12] and Anderson et al. [13]. 4. Discussion WWM processed from unrefined wheat (whole wheat grain), has its germ, endosperm and bran (collectively called whole kernel) intact unlike the refined wheat, which retains only the endosperm that is made up of mainly carbohydrate. This reason accounts for the higher nitrogen free extract (79%) Jenkins et al. [14] reported for white flour, refined wheat made solely from endosperm in comparison with ours (67.73%). WWM germ is rich in protein, vitamin Bs and omega 3 and 6 fatty acids and its bran rich in crude fiber, iron and vitamin Bs [4,15,16] and these could be
adduced for its moderately good protein content and a fairly good amount of crude fat and crude fiber content. Schwartz [15] reported that WWM contained omega 3 (a-linolenic acid) and 6 (linoleic acid and g-linolenic acid) fatty acids and a higher fiber percentage than white flour (refined form), whose germ and bran had been removed [4]. Fortification of WWM with soy flour improved crude protein content from 13.86% to 22.83%, crude fat from 2.87% to 6.28%, crude fiber content from 2.61% to 4.31% and ash content from 1.73% to 1.95%, but reduces NFE and moisture contents from 67.73% to 54.80% and 11.20% to 9.75% respectively because; soy flour is considered equivalent to animal protein in quality and as a complete protein, it contains plenty essential amino acids, and also a source of polyunsaturated (linoleic acid and linolenic acid), monounsaturated fatty acids e.g. oleic acid [17,18], and fiber (both soluble and insoluble) [19]. Thus, all these qualities in addition of being an isoflavone helped soy to improve the nutritional content of WWM in SFFWWM as shown by the proximate analysis results. Low GI foods are not quickly digested or metabolized to an extent that shoot up the blood glucose levels rapidly, but are rather slowly digested to gradually release glucose into the blood in a level that would not cause any significant rise in blood glucose level that would consequently create any dramatic spike in insulin levels [20,21], which could lead to insulin resistance (type 2 DM) and excessive weight gain (as in obese person) in a long term [21]. In low GI diet, there is less or moderate insulin secretion and a gradual glucose clearance from the blood stream that would subsequently result in greater satiety and consumption of fewer calories throughout the day [11], which would cause reduction in blood glucose levels and lesser insulin spike than in high GI foods hence, the risk of having DM reduced [21,22].
Fig. 2. Subject B blood glucose response curve for D-Glucose, Whole wheat meal and Soy fortification.
Please cite this article in press as: S.A. Emaleku, et al., Talinum triangulare Whole wheat meal fortified with soy flour consumed with Talinum triangulare (gbure) soup glycemic index and the test human subjects’ lipid profiles, Diab Met Syndr: Clin Res Rev (2017), http://dx.doi.org/ 10.1016/j.dsx.2017.08.007
G Model DSX 853 No. of Pages 7
S.A. Emaleku et al. / Diabetes & Metabolic Syndrome: Clinical Research & Reviews xxx (2017) xxx–xxx
5
Fig. 3. Subject/ C blood glucose response curve for D-Glucose, Whole wheat meal and Soy fortification.
Therefore, the low GI values 55% and 41% of the test meals (WWM and SFFWWM consumed with Talinum triangulare soup) respectively are indication that the test meals would have been metabolized slowly and absorbed gradually, and obviously showed the reason for the lower and lowest blood glucose spike in human subjects respectively in comparison with the control meal (DG) as shown in Figs. 1–4. From Figs. 1–4, it could be deduced that; WWM and SFFWWM consumed with Talinum triangulare soup were moderately and slowly metabolized respectively [4,16] to cause lesser spike (little increase) in blood glucose levels of the subjects in contrast with DG that was rapidly metabolized to quickly release blood glucose into the blood stream to an extent that greatly elevate blood sugar level (high spike) of the human subjects [21,20]. It is then suffice to say that; GI is directly proportional to blood glucose response curve/ IAUC, the higher the GI of a food the higher its blood glucose response curve/IAUC and vice versa, and Table 2 and Figs. 1–4 results affirm this assertion. Therefore, the lesser blood glucose response curves of the test meals in comparison with the control meal re-affirms WWM and SFFWWM consumed with Talinum triangulare soup to be low GI foods and suggests that they could not be risk factors for DM, because there would be little or no elevation of blood glucose that could lead to insulin resistance due to continuous significant spike in insulin levels [11,23]. According to Kiens and Richter [24], increased insulin production as a result of high blood glucose and/or over eating of high GI foods may eventually suppress the synthesis of insulin receptors, which may consequently lead to type 2 diabetes mellitus (DM), and invariably, more carbohydrates will be converted to fats and excess of which may eventually lead to cardiovascular diseases (CVDs) or coronary heart diseases (CHDs) such as heart attack, stroke, hypertension etc.
Furthermore, since GI is positively correlated with CVDs risk factors (TC, TG, LDL-C and VLDL-C) and negatively correlated with HDL-C and TP (heart health benefiting factors), it is therefore logical to say that, the test meals, most especially SFFWWM consumed with Talinum triangulare soup with low GI values would not predispose human to DM and CVDs, but DG with high GI value would do, because excess calories would be deposited (stored) as fat in the adipose tissues, which would consequently increase the risk factors of CVDs, the genesis of CVDs [25]. According to Liu et al. [23], excess carbohydrate from high GI foods would be stored as muscle fat storage, which would eventually increase serum cholesterol levels. Therefore, high GI foods can be said to be a risk factor for DM and CVDs, but low GI foods are not, because low GI foods like the test meals, most especially SFFWWM consumed with Talinum triangulare soup with the GI of 41% would decrease lipid profile risk factors for CVDs, but increase heart health benefiting factors [23,26], and this is in line with past findings of Ludwig [21] and Van Dam et al. [26]. Moreover, since the comparison of human subjects’ lipid profiles between before meals and after meals’ consumption showed that SFFWWM consumed with Talinum triangulare soup reduced lipid profiles CVDs risk factors and increased healthyheart benefiting factors, but WWM consumed with Talinum triangulare soup did not, it then implies that soy fortification of WWM had improved its nutritional qualities in all ramifications (i. e improved protein, essential amino acids, EFAs, fibers, minerals, vitamins contents) than unfortified WWM [27,17,18], which would in turn improve its therapeutical effects in preventing or treating heart related diseases as well as DM. This is an indication that SFFWWM contains health benefiting factors that are therapeutically important than WWM [28,29].
Please cite this article in press as: S.A. Emaleku, et al., Talinum triangulare Whole wheat meal fortified with soy flour consumed with Talinum triangulare (gbure) soup glycemic index and the test human subjects’ lipid profiles, Diab Met Syndr: Clin Res Rev (2017), http://dx.doi.org/ 10.1016/j.dsx.2017.08.007
G Model DSX 853 No. of Pages 7
6
S.A. Emaleku et al. / Diabetes & Metabolic Syndrome: Clinical Research & Reviews xxx (2017) xxx–xxx
Fig. 4. Mean blood glucose response curve of human subjects for D-Glucose, Whole wheat meal and Soy fortification.
According to Zhan and Ho [12], soybean protein in addition to being a complete protein contains other naturally occurring constituents such as isoflavones, fibers and saponins, and these had been reported to have hypolipidemic and anti-diabetic effects, most especially saponins. Anderson et al. [13], reported significant
reductions in TC by 9.3%, LDL-C by 12.9% and TG by 10.5% with a small insignificant increase in HDL-C by 2.4% after the consumption of soy for few days. Therefore, the non-significance difference in the lipid profiles of the test human subjects between when they consumed WWM with Talinum triangulare soup and when they
Table 3 Relationship Between Glycemic Index And Lipid Profiles. PARAMETERS
TC
TG
HDL-C
LDL-C
VLDL-C
TP
GI
TC TG HDL-C LDL-C VLDL-C TP GI
1.00000 0.91854S -0.50474NS 0.89348S 0.90956S -0.41961NS 0.40239NS
0.91854S 1.00000 -0.48396NS 0.92825S 0.99806S -0.69820NS 0.40397NS
-0.50474NS -0.48396NS 1.00000 -0.52591NS -0.51078NS 0.27671NS -0.85314S
0.89348S 0.92825S -0.52591NS 1.00000 0.93445S -0.63929NS 0.37795NS
0.90956S 0.99806S -0.51078NS 0.93445S 1.00000 -0.71824S 0.41566NS
-0.41961NS -0.69820NS 0.27671NS -0.63929NS -0.71824S 1.00000 -0.32996NS
0.40239NS 0.40397NS -0.85314S 0.37795NS 0.41566NS -0.32996NS 1.00000
Note: Comparison is strictly within the same parameter. The superscripts S and NS mean differ significantly and no significant difference respectively, at (p < 0.05).
Table 4 Human Subjects Lipid Profiles Magnitude Changes After Meals’ Consumption. PARAMETERS (mg/dl) MEAL TYPES
TC
TG
HDL-C
LDL-C
VLDL-C
TP
DG WWM SFFWWM LSD
28.67A 8.76 2.67B 4.67 -1.67B 1.86 22.15
17.00A 8.89 2.33BA 1.76 -2.33B 2.60 18.01
-3.00A 5.29 -1.00A 1.53 1.67A 1.86 10.12
28.33A 10.09 4.00B 2.52 -1.33B 3.93 24.13
3.67A 1.76 0.67BA 0.33 -0.67B 0.67 3.29
-2.00B 1.73 5.67A 1.20 8.00A 1.73 4.21
Note: Comparison is strictly within parameters. The results were expressed in mean SEM with LSD. Values with the same superscript location do not differ significantly but those with different superscript do at (P < 0.05) significance.
Please cite this article in press as: S.A. Emaleku, et al., Talinum triangulare Whole wheat meal fortified with soy flour consumed with Talinum triangulare (gbure) soup glycemic index and the test human subjects’ lipid profiles, Diab Met Syndr: Clin Res Rev (2017), http://dx.doi.org/ 10.1016/j.dsx.2017.08.007
G Model DSX 853 No. of Pages 7
S.A. Emaleku et al. / Diabetes & Metabolic Syndrome: Clinical Research & Reviews xxx (2017) xxx–xxx
consumed SFFWWM with Talinum triangulare soup could be attributed to the following reasons: 1. The test human subjects were only fed once and not for a prolong period of time. 2. The ratio 3:1 soy fortification might probably not contain the at least 25 g daily soy protein consumption or 26 mg per gram soy protein that Zhan and Ho [12] found to have therapeutic effects on lipid profiles by reducing the risk factors. 3. The test human subjects might probably have recently used some antibiotic drugs before the commencement of the experiment, which would have killed both the harmful and friendly intestinal bacteria that Setchell et al. [30] and Axelson and Setchell [31] found to be important for isoflavones metabolism into effective equol of higher therapeutic effects. 4. The test human subjects used fall within the normal range lipid profiles values, unlike Law et al. [17] and Messina et al. [18] that used hypercholesterolemic humans and found significant difference, but found no significance difference when hypocholesterolemic adult humans were used. It can then be inferred/concluded that fortifying foods with soy flour like SFFWWM would be a good nutrient/dietary (nutritionaltherapeutical) choice in the prevention, treatment and control of DM and CVDs, since SFFWWM consumed with Talinum triangulare soup has low GI value, and reduced lipid profiles CVDs risk factors, but increased healthy-heart benefiting factors than WWM consumed with Talinum triangulare soup. Conflict of interest None Acknowledgements We so much appreciate the Lord Almighty, for His guidance and protection during this research period. We also thank Dr. O.A. Obembe, a senior lecturer in the department of Plant Science and Biotechnology of Adekunle Ajasin University, Akungba-Akoko (AAUA), Ondo State for his contributions toward the success of this study, most especially in identifying the food samples. The assistance of Dr. A.O. Olusola, the amiable incumbent Head of Department of Biochemistry Department, AAUA and Dr. J.A. Saliu cannot be forgotten in a hurry. We deeply acknowledge the support and cooperation of our families that spur us into action for speedy completion of this study. God bless you all, thank you all. References [1] Slavin JL, Lampe J, Hutchins AM, Karr SC. Correlation between dietary glycemic index and cardiovascular disease risk factors among Japanese women. Eur J Clin Nutr 1997;58:1472–8. [2] Feskens EJ, Du H, Anthony M, David BM. Dietary glycemic index from an epidemiological point of view. Int J Obes (Lond) 2006;30(suppl. 3):66–71. [3] Jenkins DJ, Wolever TM, Collier GR, Ocana A, Rao AV, Buckley G, et al. Metabolic effects of a low-glycemic index diet. Am J Clin Nutr 1981;46:968–75.
7
[4] Piperno D. Processing of wild cereal grains in the upper Palaeolithic revealed by starch grain analysis. Nat J 2004;430(70):670–3. [5] USDA National Nutrient Database for Standard Reference. United States Department of Agriculture; 2003. [6] Ortega LE, Villegas E, Vasal KS. A comparative study of protein changes in normal and quality protein maize during tortilla making. Cereal Chem 1986;63:446–51. [7] Waliszewski NK, Estrada Y, Parido V. Lysine and tryptophan fortification of nixtamalized corn flour. Int J Food Sci Nutr 2000;80:237–42. [8] Omueti O, Morton O. Development, acceptability, nutritional and physical characteristics of protein improved Nigerian abari (maize meal) prepared from soya and maize flours. Int J Food Sci Nutr 1996;47:369–75. [9] Wolever TM, Jenkins DJ, Jenkins AL, Josse RG. The glycemic index: Methodology and clinical implications. Am J Clin Nutr 1991;54:846–54. [10] Freeman H. Slowly digested and absorbed carbohydrate in traditional bush foods: a protective factor against diabetes. Diab Care 2005;321:436–43. [11] Brand-Miller JC, Holt SH, Pawlak DB, McMillan J. Glycemic index and obesity. Am J Clin Nutr 2005;76:281–5. [12] Zhan S, Ho SC. Meta-analysis of the effects of soy protein containing isoflavones on the lipid profiles. Am J Clin Nutr 2005;81:397–408. [13] Anderson JW, Bryan MD, Johnstone M, Cook-Newell ME. Meta-Analysis of the effect of soy protein intake in serum. N Engl J Med 1995;333:276–82. [14] Jenkins DJA, Kendall CWC, Jackson CC, Connelly PW, Parker FDT, Vidgen E, et al. Effects of high and low isoflavone soy foods on blood lipids, oxidized LDL, homocysteine, and blood pressure in hyperlipidemic men and women. Am J Clin Nutr 2008;76:365–72. [15] R Schwartz, A whole grain of truth: The authoritative guide to the glycemic index and the dietary solution for lifelong health. [16] Wikipedia Wholegrain intake is favorably associated with metabolic risk factors for type 2 diabetes and cardiovascular disease in the Framingham Offspring Study, (2009). [17] M R Law, N J Wald, S G Thompson, By how much and how quickly does reduction in serum cholesterol concentration lower risk of ischemic heart disease? (1994) 308: 367–372. [18] Messina M, Lane B, Setchell KV. Soy protein, soybean isoflavones, and coronary heart disease risk. Fut Lipidol 1994;2:55–74. [19] Gupta Y. Nutritive value of soy bean. Int J Trop Agric 1987;3:15–23. [20] Allan A. Grains industry trends in production-results from today’s farming practices. Grains Council of Australia Limited; 2006. p. 18–27. [21] Ludwig DS. Glycemic index: physiological mechanisms relating to obesity, diabetes and cardiovascular diseases. JAMA 2002;287:2414–23. [22] Sheard NF, Clark NG, Brand-Miller JC. Dietary carbohydrate (amount and type) in the prevention and management of diabetes: a statement by the American diabetes association. 2004. [23] Liu S, Manson JE, Buring JE, Stampfer MJ, Willett WC, Ridker PM. Relation between a diet with a high glycemic load and plasma concentrations of highsensitivity C-reactive protein in middle-aged women. Am J Clin Nutr 2000;75:492–8. [24] Kiens JF, Ritcher TM. Correlation between dietary glycemic index and cardiovascular disease risk factors among Japanese women. Eur J Clin Nutr 1996;58:1472–8. [25] Uchiki T, Weikel KA, Jiao W. Glycation-altered proteolysis as a pathobiologic mechanism that links dietary glycemic index, aging, and age-related disease in non-diabetics. Aging Cell 2012;11(1):1–13. [26] Van Dam RM, Visscher AW, Feskens EJ, Verhoef P, Kromhout D. Dietary glycemic index in relation to metabolic risk factors and incidence of coronary heart diseases. Eur J Clin Nutr 2000;54:726–31. [27] Lokesh JC, Reynolds K, Chin A, Lees KA, Nguyen A, Bujnowski D, et al. A Metaanalysis of the effect of soy protein supplementation on serum lipids. Am J Cardiol 2004;98(5):633–40. [28] Ali MB. Characteristics and production cost of US wheat farms. ERS Press, USDA; 2002. p. 974–5. [29] Riaz MN. Soy applications in foods. Boca Raton, FL: CRC Press; 2006. p. 493–8. [30] Setchell KDR, Brown NM, Desai P, Zimmer-Nechemias L, Wolfe BE, Brashear WT, et al. Bioavailability of pure isoflavones in healthy humans and analysis of commercial soy isoflavone. J Nutr 1997;131(1):1362–75. [31] Axelson M, setchell KDR. The excretion of lignans in rats: evidence for an intestinal bacterial source for this new group of compounds. FEBS Lett 1981;37–45.
Please cite this article in press as: S.A. Emaleku, et al., Talinum triangulare Whole wheat meal fortified with soy flour consumed with Talinum triangulare (gbure) soup glycemic index and the test human subjects’ lipid profiles, Diab Met Syndr: Clin Res Rev (2017), http://dx.doi.org/ 10.1016/j.dsx.2017.08.007