Plasma lipid effects of corn oil and extra-virgin olive oil in hypercholesterolaemic subjects: a randomised, controlled trial

The aim of our study was to directly compare the metabolic effect of monounsaturated fatty acid rich oils and polyunsaturated fatty acid rich oils on the plasma lipid pattern of moderately hypercholesterolaemic subjects under controlled isocaloric condition. After a 30-day run-in diet, 44 healthy Caucasian subjects with moderate hypercholesterolaemia were randomly assigned to one of four different isocaloric diets, differing only regarding the oil used (corn oil, corn oil supplemented with vitamin E, extra-virgin olive oil or different self-selected oils), for 45 days. At the end of the study, when compared to the baseline value, low-density lipoprotein (LDL)-cholesterolaemia was significantly lower only in patients taking corn oil (-13.9%; 95% CI -5.9 to -20.1; p = 0.02) or corn oil with added vitamin E (-19.1%; 95% CI -6.9 to -24.1; p = 0.03). Differences in plasma high-density lipoprotein (HDL)-cholesterol and triglyceride levels from baseline levels and between the four diets did not reach statistical significance.