EFFECT OF SUPPLEMENTATION WITH DIFFERENT DOSES OF DHA ON THE LEVELS OF CIRCULATING DHA AS NONESTERIFIED FATTY-ACID IN SUBJECTS OF ASIAN INDIAN BACKGROUND

There is evidence to indicate that the high rates of coronary heart di sease and myocardial infarction amongst Indians of Asian descent may b e partly related to circulating non-esterified fatty acids (NEFA). As docosahexaenoic acid (DHA,22:6n-3) in NEFA form has been found to exhi bit anti-platelet aggregatory and anti-arrythmic potential in vitro, t he effect of supplementary DHA was examined in healthy subjects of Asi an Indian background. Furthermore, time-and dose-dependent changes in absolute levels of DHA as NEFA or phospholipid (PL) were compared. The subjects consumed 8 capsules daily of placebo (DHA-free) or low DHA ( 0.75 g/day) or high DHA (1.50 g/day) over 6 wks. Fasting blood samples were drawn at days 0, 21, and 42 for analysis of serum lipid/lipoprot ein composition. No significant effect of DHA. supplementation on the levels of serum lipid/lipoproteins (including Lp[a]) or blood pressure was found. However, the DHA level in serum phospholipid rose by 167% overall with low-dose supplementation (from 2.4-6.4 mol%) but only by an additional 23% upon doubling the dose from 0.75 g to 1.50 g/day. Fu rthermore, after 6 weeks of supplementation with 0.75 g or 1.5 g DHA/d ay, absolute concentrations of DI-W as PL were not significantly diffe rent from the corresponding 3-week values. Interestingly, the absolute concentrations of serum DHA. as NEFA showed a marked rise with low-do se supplementation (by 212% overall, from 2.4 to 7.5 mu M) and a furth er 70% rise (to 12.7 mu M) upon doubling the supplementation from 0.75 to 1.50 g/day. As well, the 6-week concentrations (DHA-NEFA) were sig nificantly different than the corresponding 3-week values at both dose levels. Elevation of circulating DHA-NEFA levels via DHA supplementat ion, as shown herein, to concentrations that exhibit anti-thrombotic a nd anti-arrhythmic potential in vitro needs to be extended to trials w here clinical end-points are determined.