EFFECT OF LONG-TERM OLIVE OIL DIETARY INTERVENTION ON POSTPRANDIAL TRIACYLGLYCEROL AND FACTOR-VII METABOLISM

Although the beneficial effects of Mediterranean-type diets, which are rich in olive oil, a good source of monounsaturated acids (MUFAs), ar e generally accepted, little is known about the effects of long-term d ietary MUFA intake on postprandial lipoprotein metabolism and hemostas is. This study used a single-blind, randomized, crossover design to in vestigate the relative effects of a long-term dietary olive oil interv ention and a control [saturated fatty acid (SFA)-enriched] diet on pos tprandial triacylglycerol metabolism and factor VII activity. The post prandial response to a standard test meal was investigated in 23 healt hy men who adhered to both diets for 8 wk. cis-MUFAs were successfully substituted for SFAs in the MUFA diet without affecting total dietary fat or energy intakes. The long-term dietary MUFA intervention signif icantly reduced plasma and LDL-cholesterol concentrations (P = 0.01). Postprandial triacylglycerol concentrations were significantly greater in the early postprandial period after the MUFA diet (P = 0.003). Pos tprandial factor VII activation and the concentration of the factor VI I antigen were significantly lower after the MUFA diet (P = 0.04 and P = 0 006, respectively). This study showed that isoenergetic substitut ion of MUFAs for SFAs reduces plasma cholesterol and reduces the degre e of postprandial factor VII activation. The alterations in the postpr andial triacylglycerol response suggest a greater rate of dietary fat absorption and postprandial triacylglycerol metabolism after a diet ri ch in MUFAs. This study presents new insights into the biochemical bas is of the beneficial effects associated with long-term dietary MUFA co nsumption, which may explain the lower rates of coronary mortality in Mediterranean regions.