The effects of dietary palm oil, hydrogenated rapeseed oil and hydrogenated soya oil on indices of coronary heart disease in man
Palm oil has been categorised as a saturated fat and to have a deleterious effect on the risk of CHD. In the present study, the habitual Scottish diet was replaced with palm oil (RBDPO) diet (26% en) and its effects on the indices of CHD risk was compared with the hydrogenated rapeseed (HRSO) and soya oil (HSO) diets. The result showed that RBDPO diets increased plasma total- and LDL- cholesterol concentrations but similarly increase the plasma HDL-cholesterol concentrations. In contrast, the above parameters were decreased in the hydrogenated oil diet groups. Changes in the indicators of lipid peroxidation were not different between groups although plasma conjugated dienes concentrations were shown to increase significantly in the HSO diet group at the end of the study period. Plasma glutathione peroxidase activity was also shown to increase in both hydrogenated oil diet groups. Plasma total Lp(a) concentrations were decreased in the RBDPO diet group whereas they were increased in the hydrogenated oil diet groups. The present study suggested that the effects of RBDPO in decreasing the plasma total Lp(a) concentrations might be due to its effects in increasing the clearance of plasma postprandial TRP-apo(a) by the B/E receptor pathway. It is concluded in the present study that despite the high content of RBDPO incorporated into the Scottish diet (65% of total fat intake), the ingestion of this diet did not confer deleterious effects on the risk of CHD when compared with the HRSO and HSO diets.