The effect of dietary palm oil, hydrogenated rape and soya oil on indices of coronary heart disease risk in healthy Scottish volunteers

Abstract

Effects of three highly saturated fat diets containing either palm fat (RBDPO), hydrogenated soya fat (HSO) or hydrogenated rapeseed fat (HRSO), on short-term indicators of coronary heart disease (CHD) risk in healthy Scottish volunteers were compared. “Free living” subjects (53) were randomly assigned to one of three experimental diets or the “wild” habitual diet group for eight week periods. Fasting blood samples were collected at week 0 (baseline) and at two week intervals. Plasma lipoprotein-cholesterol, triglycerides and indices of lipid peroxidation were assessed. RBDPO diets increased plasma total-, LDL- and HDL-cholesterol (i.e. both beneficial and detrimental effects); HRSO and HSO diets decreased total- and HDL-cholesterol. Changes in cholesterol in ‘wild’ volunteers were similar (0.4m.mol./L) to those in experimental groups (0.4–0.5m.mol./L) with similar absolute values. Plasma triglycerides were reduced after four weeks RBDPO but not HSO or HRSO; values in the “wild” group did not differ from baseline or from other groups. RBDPO reduced indices of lipid peroxidation. HSO increased whole-blood aggregation and plasma conjugated dienes (CD). Physiological relevance of such small changes in indices of CHD risk elicited by the saturated diets are questionable.