Numerous epidemiological and controlled interventional trials have supported the health benefits of long-chain
omega-3 fatty acids in the form of
docosahexaenoic acid (DHA, 22:6n-3) plus
eicosapentaenoic acid (EPA, 20:5n-3) from fish and
fish oils as well as from algal sources. The beneficial effects on
cardiovascular disease and related mortality including various risk factors for cardiovascular disease (particularly lowering circulating
triglyceride levels and the
triglyceride:HDL-
cholesterol ratio) have been observed in the absence of any concomitant blood
cholesterol lowering. With appropriate dosages, consistent reductions in both fasting and postprandial
triglyceride levels and moderate increases in fasting
HDL-cholesterol levels have been observed with algal DHA in the majority of trials. These results are similar to findings for
fish oils containing DHA and EPA. Related to greater fish intake, higher levels of DHA in circulating blood
biomarkers (such as serum
phospholipid) have been associated with reduced risks for the progression of
coronary atherosclerosis and lowered risk from
sudden cardiac death. Controlled clinical trials have also indicated the potential for algal DHA supplementation to have moderate beneficial effects on other
cardiovascular disease risk factors including blood pressures and resting heart rates. Recommended intakes of DHA+EPA from numerous international groups for the prevention and management of
cardiovascular disease have been forthcoming, although most have not offered specific recommendations for the optimal individual intake of DHA and EPA.