Number of days required for assessing usual nutrient and antioxidant intakes in a sample from a U.S. healthy college population.

OBJECTIVE: The primary aim of this study was to determine the number of days required to assess usual antioxidant intake with a defined level of accuracy in a sample of healthy college students. The secondary aim of this study was to increase the validity of the calculation of days by first determining the prevalence of misreporting energy intake in 30-d food records (FRs). METHOD: We examined the percentage of misreporting, the within- and between-person variations of nutrient intake, and the minimum days required to estimate a person's true intake with a correlation coefficient r ≥ 0.9. Sixty students from the University of Connecticut completed a 30-d FR, which was analyzed using the Nutrition Data System for Research software combined with Flavonoid and Proanthocyanidin Provisional Table. RESULTS: Twenty-seven percent (44 average reporters) included in the dietary analysis misreported after applying the Goldberg cutoff equation. The within-person variation was greater than the between-person variation with the variance ratios ranging from 1.10 to 10.51. After adjusting for energy and sex, a 7-d FR was adequate to achieve r ≥ 0.9 for fat, carbohydrate, protein, lycopene, and proanthocyanidin, whereas α-tocopherol, total carotenoids, and flavonoids required 8 d. The remaining antioxidants required between 10 and 45 d. CONCLUSIONS: Overall, micronutrients and antioxidants had a greater daily variation than macronutrients and the majority required more than 7 d to assess usual intakes for this population.

Gene-diet interactions with polymorphisms of the MGLL gene on plasma low-density lipoprotein cholesterol and size following an omega-3 polyunsaturated fatty acid supplementation: a clinical trial.

BACKGROUND: Omega-3 (n-3) polyunsaturated fatty acid (PUFA) consumption increases low-density lipoprotein (LDL) cholesterol (C) concentrations and particle size. Studies showed that individuals with large, buoyant LDL particles have decreased risk of cardiovascular diseases. However, a large inter-individual variability is observed in LDL particle size. Genetic factors may explain the variability of LDL-C concentrations and particle size after an n-3 PUFA supplementation. The monoglyceride lipase (MGLL) enzyme, encoded by the MGLL gene, plays an important role in lipid metabolism, especially lipoprotein metabolism. The aim of this study was to investigate if polymorphisms (SNPs) of the MGLL gene influence the variability of LDL-C and LDL particle size in response to an n-3 PUFA supplementation. METHODS: 210 subjects completed the study. They consumed 5 g/d of a fish oil supplement (1.9-2.2 g eicosapentaenoic acid and 1.1 g docosaexaenoic acid) during 6 weeks. Plasma lipids were measured before and after the supplementation period and 18 SNPs of the MGLL gene, covering 100% of common genetic variations (minor allele frequency ≥0.05), have been genotyped using TaqMan technology (Life Technologies Inc., Burlington, ON, CA). RESULTS: Following the n-3 PUFA supplementation, 55% of subjects increased their LDL-C levels. In a model including the supplementation, genotype and supplementation*genotype effects, gene-diet interaction effects on LDL-C concentrations (rs782440, rs6776142, rs555183, rs6780384, rs6787155 and rs1466571) and LDL particle size (rs9877819 and rs13076593) were observed for the MGLL gene SNPs (p < 0.05). CONCLUSION: SNPs within the MGLL gene may modulate plasma LDL-C levels and particle size following an n-3 PUFA supplementation. This trial was registered at clinicaltrials.gov as NCT01343342.

Effects of age, sex, body mass index and APOE genotype on cardiovascular biomarker response to an n-3 polyunsaturated fatty acid supplementation.

OBJECTIVES: To test whether age, sex, body mass index (BMI), and the apolipoprotein E (APOE) genotype are associated with the metabolic response to an n-3 polyunsaturated fatty acid (PUFA) supplementation. METHODS: 210 subjects followed a 2-week run-in period based on Canada's Food Guide and underwent a 6-week 5 g/day fish oil supplementation (1.9 g of eicosapentaenoic acid and 1.1 g of docosahexaenoic acid). Cardiovascular disease risk factors were measured. RESULTS: n-3 PUFA supplementation was associated with a decrease of plasma triglyceride levels (p = 0.0002) as well as with an increase of fasting glucose (FG) levels (p = 0.02). Age was associated with post-intervention plasma total cholesterol (p = 0.01), low-density lipoprotein cholesterol (p = 0.007), apolipoprotein B (p = 0.04), and insulin (p = 0.002) levels. Sex was associated with post-intervention plasma high-density lipoprotein cholesterol levels (p = 0.02). BMI was associated with plasma FG (p = 0.02) and insulin levels (p < 0.0001) after the supplementation. APOE genotype was associated with FG (p = 0.001) and C-reactive protein levels (p = 0.03) after the supplementation. CONCLUSION: Results suggest that age, sex, BMI, and the APOE genotype contribute to the inter-individual variability observed in the metabolic response to an n-3 PUFA supplementation.

Omega-3 fatty acids, polymorphisms and lipid related cardiovascular disease risk factors in the Inuit population.

BACKGROUND: Tissue concentrations of fatty acids (FAs) and genetic variations are well-known factors which affect the cardiovascular disease (CVD) risk. The objective was to examine whether the genetic variability of 20 candidate genes and red blood cells (RBCs) percentage of total n-3 polyunsaturated fatty acids (PUFA), a biomarker of dietary n-3 PUFA intake, modulate lipid related CVD risk factors in the Inuit population. METHODS: Data from the Qanuippitaa Nunavik Health Survey (n = 553) were analysed via multivariate regression models with 40 known polymorphisms, RBCs percentage of n-3 PUFA, and the interaction term to take into account the effect on plasma lipid and apolipoporotein levels. RESULTS: Individuals being heterozygotes for CETP C-4502T (rs183130) or G-971A (rs4783961) together with higher n-3 PUFA had lower triacylglycerol (TG) concentrations compared to homozygotes for the minor allele. Further, effects of a stronger beneficial association between n-3 PUFA in RBCs and plasma lipid parameters- including lower total cholesterol (TC), lower low-density lipoprotein cholesterol (LDL-C) or higher high-density lipoprotein cholesterol (HDL-C) concentrations- were associated with AGT M235T (rs699) TT genotype, CETP G-971A (rs4783961) AG genotype, T allele carriers of CETP C-4502T (rs183130), and T allele carriers of CETP Ile405Val (rs5882). In contrast, higher n-3 PUFA in RBCs were associated with adverse lipid profiles- including increased LDL-C, increased apolipoprotein B100 or decreased HDL-C concentrations- in G allele carriers of the APOA5 -3 A/G (rs651821), C allele carriers of APOA5 T-1131C (rs662799), G carriers of APOC3 SstI (rs5128) and G carriers of APOA4 Asn147Ser (rs5104). CONCLUSION: Overall, these results suggest that percentage of total n-3 PUFA of RBCs are associated with lipids related CVD risk factors conferred by genetic variations in the Inuit population.

Polymorphisms in genes involved in the triglyceride synthesis pathway and marine omega-3 polyunsaturated fatty acid supplementation modulate plasma triglyceride levels.

BACKGROUND: Marine omega-3 (n-3) polyunsaturated fatty acids (PUFA) reduce plasma triglyceride (TG) levels. Genetic factors such as single nucleotide polymorphisms (SNPs) could be responsible for the variability of the plasma TG response to n-3 PUFA supplementation. Previous studies have demonstrated that n-3 PUFA supplementation using fish oil modified the expression levels of three genes involved in the TG synthesis pathway (GPAM, AGPAT3 and AGPAT4) in peripheral blood mononuclear cells. METHODS: A total of 210 subjects consumed 5 g/day of a fish oil supplement for 6 weeks. Plasma lipids were measured before and after the supplementation period. Three SNPs in GPAM, 13 SNPs in AGPAT3 and 35 SNPs in AGPAT4 were genotyped. RESULTS: In an ANOVA for repeated measures adjusted for age, sex and BMI, genotype effects on plasma TG levels were observed for rs1838452 in AGPAT3 as well as for rs746731 and rs2293286 in AGPAT4. Genotype × supplementation interaction effects on plasma TG levels were observed for rs2792751 and rs17129561 in GPAM as well as for rs3798943 and rs9458172 in AGPAT4 (p < 0.05). CONCLUSION: These results suggest that SNPs in genes involved in the TG synthesis pathway may influence plasma TG levels after n-3 PUFA supplementation.

Assessment of nutrient adequacy with supplement use in a sample of healthy college students.

OBJECTIVES: Limited information is available on the nutritional status and the impact of supplements on nutrient adequacy in college students. This study aimed to assess nutritional status and evaluate the contribution of supplement use to overall nutrient adequacy in a sample of healthy college students. METHODS: Sixty subjects (40 women and 20 men) were randomly recruited from those attending the University of Connecticut. Food records were collected over 30 consecutive days for each subject. In addition, health and lifestyle information was collected at the beginning and end of the study period. RESULTS: After excluding misreporting, only 44 subjects were eligible for assessing nutritional status. More than 40% of female students had intakes below the estimated average requirements for vitamins D and E, calcium, and magnesium. Supplement users had significantly higher average intakes than nonusers from dietary sources for protein, folate, niacin, vitamin E, magnesium, and zinc (p < 0.05). With the addition of supplements, supplement users consumed significantly more for all nutrient intakes except vitamin A than nonusers (p < 0.05). Nutritional adequacy of supplement users was significantly higher for vitamins D and E and magnesium compared with nonusers (p < 0.05). CONCLUSIONS: Overall, men and women were consuming intakes below adequacy for most nutrients, and supplement usage increased nutrient intake and adequacy levels in this young adult population.