Jan 17 2012 --- The endothelial cells that form the inner walls of the blood vessels play an important role in the development of cardiovascular disease (CVD). Dysfunction of the endothelium has been shown to be an early risk marker of CVD.  Interestingly, high intake of fish oils, which are rich in long-chain omega-3 fatty acids, such as DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid), is associated with a lower risk of CVD.  The mechanism underlying this association is not completely understood, but effects of long-chain, omega-3 fatty acid on endothelial function are possible.

In a recent study conducted in the United Kingdom among 59 men and women (mean age 28 years), British researchers investigated the effects of feeding DHA-rich fish oil on vascular function following the consumption of a high-fat meal.  In this case, subjects were fed a single oral fat load composed of palm stearin, skimmed milk powder, chocolate powder, emulsifier and water, either with or without DHA-rich fish oil (77% DHA, 9% EPA).  Vascular function was measured in a variety of ways, including a measure of flow-mediated dilatation of the brachial artery (found on the inner aspect of the elbow) following 5-minutes of occlusion of blood flow with a blood pressure cuff. Measurement of the relative increase in diameter of the brachial artery before and after occlusion is an indicator of vascular endothelial function – measured as FMD (flow-mediated dilatation).

The chief finding in this study was that consumption of the high-fat meal resulted in an impairment of FMD.  However, if the subject consumed the high-fat load that was enriched with the DHA-rich fish oil, then the ill effects of consuming the high-saturated fat meal on vascular reactivity were completely overcome. These findings are consistent with the idea that diets rich in DHA can have beneficial effects on CVD.