Journal Name:
Journal of Lipid Research
Article Title:
An olive oil-rich diet results in higher concentrations of LDL cholesterol and a higher number of LDL subfraction particles than rapeseed oil & sunflower oil diets
Date Written:
2000
Volume:
41
Number:
Page:
1901
Author(s):
Pedersen, A.; Baumstark, M.; Marckmann, P.; Gylling, H.; Sandstr�m, B.
Article:
Science has established that dietary fatty acid composition influences plasma lipids and lipoproteins associated with the development of atherosclerosis and ischemic heart disease (IHD). Conventional risk markers of IHD are not sufficient for identifying individuals at high risk of IHD and additional blood parameters such as elevated fasting plasma insulin, apolipoprotein B (apoB), triacylglycerols (TAG), and nonesterified fatty acids (NEFA) have been studied in relation to an increased risk of IHD. Results from clinical studies have suggested a strong relationship between a predominance of small, dense LDL particles (subclasses) in plasma and an increased risk of myocardial infarction or coronary atherosclerosis and may be explained by a lower binding affinity to the LDL receptor or increased susceptibility to oxidation. Only limited information exists concerning the effect of diet on very low density lipoprotein (VLDL), intermediate density lipoprotein (IDL), or LDL and HDL subclasses. Limited available evidence suggests that the amount and type of dietary fat influence the LDL subfraction profile, but it is not clear whether common edible vegetable oils leading to varying blood lipid levels also differ with respect to lipoprotein subclass profiles.
In the present study, the effects of three experimental diets rich in different vegetable oils (olive oil [OO], canola oil [CO], and sunflower oil [SO]) on blood lipids and on the number, size, and composition of LDL and HDL subfractions. It was hypothesized that CO, because of its lower content of saturated fatty acids (SFA) compared with OO and its higher content of n-3 fatty acids, would be associated with the most favorable lipoprotein subclass profile. It was also expected that SO, because of its higher content of polyunsaturated fatty acids (PUFA), would lead to lower blood lipid concentrations, but higher, less favorable total and LDL:HDL cholesterol ratios compared with the OO and CO diets.
Eighteen young, healthy men participated in a double-blinded randomized cross-over study (3-week intervention period) with 50 g of oil per 10 MJ incorporated into a constant diet. Plasma cholesterol, triacylglycerol, apolipoprotein B, and VLDL, IDL, and LDL cholesterol concentrations were 10-20% higher after consumption of the OO diet compared with the CO and SO diets. The size of IDL, VLDL, and LDL subfractions did not differ between the diets, whereas a significantly higher number (apolipoprotein B concentration) and lipid content of the larger and medium-sized LDL subfractions were observed after the olive oil diet compared with the rapeseed oil and sunflower oil diets. Total HDL cholesterol concentration did not differ significantly, but HDL2a cholesterol was higher after OO and CO compared with SO. The diets resulted in higher LDL: HDL and total:HDL cholesterol ratios after the OO and SO diets compared with the CO diet. The total:HDL cholesterol ratio has been reported to be a better predictor of IHD than other conventional risk markers (total cholesterol, LDL cholesterol or TAG) in a number of studies. Thus, in this study the CO diet resulted in the most favorable lipid ratios compared with both OO and SO. Taken together, the CO diet seemed to have more favorable effects with regard to blood lipid and lipoprotein subfractions compared with SO and OO.
The CO and SO had more favorable effects on blood lipids and plasma apolipoproteins as well as on the number and lipid content of LDL subfractions compared with OO. Some of the differences may be attributed to differences in the squalene and phytosterol contents of the oils. It was observed that when vegetable oils accounted for a substantial part of the total fat intake, the oil quality was shown to affect the LDL and HDL subclass profiles differently. Whether these differences may be due to differences in fatty acid composition is still to be resolved., , , , ,
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