The postprandial effect of components of the Mediterranean diet on endothelial function

OBJECTIVES This study investigated the postprandial effect of components of the Mediterranean diet on endothelial function, which may be an atherogeni c factor. BACKGROUND The Mediterranean diet, containing olive oil, pasta, fruits, veg etables, fish, and nine, is associated with ail unexpectedly low rate of ca rdiovascular events. The Lyon Diet Heart Study found that a Mediterranean d iet, which substituted omega-3-fatty-acid-enriched canola oil for the tradi tionally consumed omega-9 fatty-acid-rich olive oil, reduced cardiovascular events. METHODS We fed 10 healthy, normolipidemic subjects five meals containing 90 0 kcal and 50 g far. Three meals contained different fat sources: olive oil , canola oil, and salmon. Two olive oil meals also contained antioxidant vi tamins (C and E) or foods (balsamic vinegar and salad). We measured serum l ipoproteins and glucose and brachial artery flow-mediated vasodilation (FMD ), an index of endothelial function, before and 3 h after each meal. RESULTS All five meals significantly raised serum triglycerides, but did no t change other lipoproteins or glucose 3 h postprandially. The olive oil me al reduced FMD 31% (14.3 +/- 4.2% to 9.9 +/- 4.5%, p = 0.008). An inverse c orrelation was observed between postprandial changes in serum triglycerides and FMD (r = -0.47, p < 0.05). The remaining four meals did not significan tly reduce FMD. CONCLUSIONS In terms of their postprandial effect on endothelial function, the beneficial components of the Mediterranean and Lyon Diet Heart Study di ets appear to be antioxidant-rich foods, including vegetables, fruits, and their derivatives such as vinegar, and omega-3-rich fish and canola oils. ( C) 2000 by the American College of Cardiology.