DHA Omega-3 Reduces Postprandial Blood Lipids
Kelly DS. et al., American Journal of Clinical Nutrition. 86:324-333 (2007)
Western Human Nutrition Research Center, Agricultural Research Service, US Department of Agriculture and Department of Nutrition, University of California Davis, CA; Veterans Affairs Northern California Health Care System, Sacramento, CA
It has been well documented that fasting triglyceride (triacylglycerol) concentrations and the levels of circulating small-dense LDL (low-density lipoprotein) particles are independent risk factors for cardiovascular disease (CVD). More recently, increasing attention has been given to the CVD risk associated with surges in the levels of both triglyceride and small-dense LDL particles following a meal (the postprandial state).
In the present study, this group evaluated the potential for daily supplementation with DHA omega-3 fatty acid to attenuate both the fasting and postprandial levels of these risk factors along with other parameters. In this double-blind, randomized, placebo-controlled parallel study, men with elevated blood triglyceride levels received either a placebo supplement (containing olive oil) or supplementary DHA at the level of 3g daily from an algal oil source over a period of 13 weeks. Fasting triglyceride levels showed a highly significant decrease of 21% for the DHA group whereas no significant changes were observed in the placebo (control) group. Measurements of postprandial (post-meal) responses up to 6 hours indicated a reduction in the area-under-the-curve of 24% for triglyceride levels and 21% for the small-dense LDL particles for those on DHA supplementation whereas no such effects were observed in the placebo group. In addition, the resting heart rate was decreased by approximately 5% with DHA supplementation whereas the small reductions in systolic and diastolic blood pressures (2.3% and 0.4%, respectively) were not significantly different as compared to the baseline (entry) values. The authors concluded that the suppression of fasting and postprandial levels of triglyceride and the small-dense LDL particles may improve overall cardiovascular health.
It should be noted that these significant beneficial effects on blood lipoprotein risk factors for cardiovascular disease in the fasted and postprandial state are of interest since much of our daily life is spent in the postprandial state (after and between meals). Since the current health-care system focuses on fasting blood lipids/lipoprotein levels with no consideration to postprandial status, it is somewhat encouraging that the beneficial effects seen with DHA supplementation on the fasting values also appear in the postprandial state. The current intake of DHA in North America is rather low (approximately 80 mg per day) in contrast to Japan where the intakes approach approximately 550-750 mg of DHA daily amongst adults. The level of DHA employed in the present study from supplementation (3000 mg DHA) cannot be obtained from regular (or even daily fish consumption) in most people. Thus, supplementation with omega-3 fatty acid concentrates containing DHA (from algal oil) or DHA-enriched fish oil concentrates would need to be employed if one were attempting to reach the levels used in the present.