Olive oil and high-oleic sunflower oil on human plasma and erythrocyte membrane lipids

Abstract

Olive oil (OO) and high-oleic sunflower oil (HOSO) were employed as a natural sources of monounsaturated fatty acids (MUFAs) over two 4-wk periods, during which each twelve participants ate OO or HOSO diets, with a 4-wk washout period between the two MUFA diets. Plasma low-density-lipoprotein (LDL) cholesterol decreased ( P < 0.05) by 9 and 6 % after OO and HOSO diets respectively. There was a significant increase of 18 % ( P < 0.01) after OO diet and 12 % ( P < 0.05) after HOSO diet in plasma high-density-lipoprotein (HDL) cholesterol. A significant decrease in plasma HDL 2-cholesterol and an increase in plasma HDL 3-cholesterol were also evident either after OO or HOSO diets. Free and esterified cholesterol decreased by 20 % ( P < 0.01) and 41 % ( P < 0.001) respectively in erythrocyte membrane after OO diet, but did not after HOSO diet. Erythrocyte phospholipids were also increased by 10 % ( P < 0.01) after OO diet, and in turn diminished the molar ratio of cholesterol to phospholipids in the membrane. These data demonstrate that the beneficial effects of dietary OO in reducing the atherogenic risk profile in healthy subjects are not equally found after HOSO-rich diet, although both vegetable oils provide a similar concentration of MUFAs.