DIETARY TRANS-FATTY-ACIDS INCREASE SERUM CHOLESTERYLESTER TRANSFER PROTEIN-ACTIVITY IN MAN

The average diet may provide some 8-10 g/day of unsaturated fatty acid s with a trans double bond. Previous studies showed that dietary trans fatty acids may simultaneously raise low-density lipoprotein (LDL) ch olesterol and reduce high-density lipoprotein (HDL) cholesterol. Human plasma contains a protein (CETP) which transfers cholesterylesters fr om HDL to lipoproteins of lower density. We hypothesized that CETP cou ld play a role in the effect of trans fatty acids on lipoproteins and measured the activity levels of CETP in serum samples from a 9-week st udy in which 55 volunteers were fed three controlled diets with differ ent fatty acid profiles. Mean activity was 114 (% of reference serum) after consumption of a high trans fatty acid diet, as opposed to 96 af ter linoleic acid and 97 after stearic acid (P < 0.02). We conclude th at the increased activity of CETP may contribute to the rise in LDL ch olesterol and the fall in HDL cholesterol seen on diets with high cont ents of trans fatty acids.