Positive Health Online

Abstract

O’SULLIVAN and COLLEAGUES,  (1)Departments of Food Science and Technology, and Nutrition, University of California, Davis, Davis, CA, Obesity and Metabolism Research Unit, and Immunity and Disease Prevention Research Unit, Western Human Nutrition Research Center, Agricultural Research Service, USDA, Davis, CA. Institute for Genetic Medicine and Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA john.newman@ars.usda.gov investigated the associations between the efficacy of ω-3 fatty acid supplementation and a broad range of nutritional and clinical factors in a double-blind, placebo-controlled trial.

Background

Although substantial variation exists in individual responses to omega-3 (ω-3) (n-3) fatty acid supplementation, the causes for differences in response are largely unknown.

Methodology

Here we investigated the associations between the efficacy of ω-3 fatty acid supplementation and a broad range of nutritional and clinical factors collected during a double-blind, placebo-controlled trial in participants of African ancestry, randomly assigned to receive either 2 g eicosapentaenoic acid (EPA) + 1 g docosahexaenoic acid (n = 41) or corn/soybean oil placebo (n = 42) supplements for 6 wk. Food-frequency questionnaires were administered, and changes in erythrocyte lipids, lipoproteins, and monocyte 5-lipoxygenase-dependent metabolism were measured before and after supplementation. Mixed-mode linear regression modelling identified high (n = 28) and low (n = 13) ω-3 fatty acid response groups on the basis of changes in erythrocyte EPA abundance (P < 0.001). Compliance was equivalent (∼88%), whereas decreases in plasma triglycerides and VLDL particle sizes and reductions in stimulated monocyte leukotriene B4 production were larger in the high-response group.

Results

Although total diet quality scores were similar, the low-response group showed lower estimated 2005 Healthy Eating Index subscores for dark-green and orange vegetables and legumes (P = 0.01) and a lower intake of vegetables (P = 0.02), particularly dark-green vegetables (P = 0.002).

Conclusion

Because the findings reported here are associative in nature, prospective studies are needed to determine if dietary dark-green vegetables or nutrients contained in these foods can enhance the efficacy of ω-3 fatty acid supplements. This trial was registered at clinicaltrials.gov as NCT00536185.

References

O'Sullivan A(1), Armstrong P, Schuster GU, Pedersen TL, Allayee H, Stephensen CB, Newman JW. Habitual diets rich in dark-green vegetables are associated with an increased response to ω-3 fatty acid supplementation in Americans of African ancestry.  J Nutr 144(2):123-31. Feb 2014. doi: 10.3945/jn.113.181875. Epub Nov 20 2013.