The nutritional importance of olive oil

Olive oil is part of the mediterranean diet, and represent predominantly MUFA oils, namely oil rich in oleic acid, and has been extensively promoted to prevent atherosclerosis and cardiovascular diseases. Consumption of virgin or rafinated olive oils induces similar effects on atherogenic (LDL-C) or anti-atherogenic (HDL-C) plasma parameters. This is explicable by consideration of the same fatty acid content, but the non-saponifiable fractions of virgin olive oil could also prevent oxidation of lipoproteins. Progressive enrichment of the diet with oleic acid induces a progressive increase of plasma HDL-C levels: and plasma phospholipid fatty acid modifications representative of a better anti-aggregating status. furthermore, increasing the level of oleic acid in the fatty meal (with olive oil), increases the postprandial modifications of HDL composition, which results in an increase of their capacity of cholesterol efflux (the first step of reverse cholesterol transport process). This could also represent a better protection against atherosclerosis. Considering the intake of fatty acids expressed in grams per day, independently of the total fat consumption, the limits for a beneficial effect on lipemia has been evaluated : a minimum intake of 24 to 28 grams/day for oleic acid is needed to obtain a beneficial effect on HDL-C, and a minimum intake of 7 to 13 grams/day for linoleic acid is needed to obtain a beneficial effect on LDL-C, with a maximum of 4.5 for an oleic/linoleic ratio.