LDL and apoB
Trans-elaidic acid raises CETP activity more than cis-oleic acid, correlating with falling HDL cholesterol (Atherosclerosis 1994)
Original title: Plasma cholesteryl ester transfer protein activity is increased when trans-elaidic acid is substituted for cis-oleic acid in the diet
Twenty-seven men completed a double-blind crossover comparison in which a background diet was supplemented with either oleic acid or its trans isomer, elaidic acid (providing about 6% energy as trans fat), to test whether trans fatty acids raise LDL and lower HDL cholesterol via increased CETP activity. Plasma CETP activity was significantly higher after the elaidic acid-rich diet than after the oleic acid diet (23.95% versus 19.61%, P < 0.001), and the change in plasma trans 18:1 fatty acids correlated significantly with the change in CETP activity (r = 0.58, P < 0.002), independent of changes in LDL cholesterol. The rise in CETP activity was in turn significantly correlated with a fall in HDL cholesterol during the elaidic acid period (r = -0.57, P < 0.01). The authors conclude that CETP shows substrate specificity, and that its increased activity with dietary trans fatty acids may contribute to a more atherogenic lipoprotein profile.
Original abstract
The trans isomer of oleic acid (elaidic acid) increases low density lipoprotein (LDL) cholesterol and decreases high density lipoprotein (HDL) cholesterol in man. One possible mechanism for this effect is that trans fatty acids increase plasma cholesteryl ester transfer protein (CETP) activity. We examined the effect of dietary trans fatty acids on activity of this protein in plasma from 27 men in a double blind crossover comparison. The background diet, containing 15% energy as fat from dairy products, meat, bread and cereals, was supplemented with oleic or elaidic acid providing a further 20% energy. The elaidic supplement provided about 6% energy as trans fatty acid. Activity of CETP in plasma was significantly higher (P < 0.001) after the elaidic acid-rich diet (23.95 +/- 1.26%) compared with the diet enriched with oleic acid (19.61 +/- 0.89%). A significant correlation between the change in plasma trans 18:1 fatty acids and the change in plasma CETP activity (r = 0.58, P < 0.002) was independent of changes in LDL-cholesterol. The increase in CETP activity was in turn significantly correlated with a fall in HDL-cholesterol among subjects during the elaidic acid-rich period (r = -0.57, P < 0.01). We have shown that CETP demonstrates substrate specificity and that the increase in activity with dietary trans fatty acids may contribute to a more atherogenic lipoprotein profile.
Summary written by cetpinhibition.org from the published abstract; figures as published. Page updated 19 August 2026. Methods.