Abstract
This review focuses on human data about the link between cardiovascular risk and dietary trans and conjugated fatty acids. Some complementary data from animals are presented. Concerning trans monoene isomers, since 1990 they were extensively studied. Intervention studies have shown that they increased LDL‐cholesterol just like saturated fatty acids (palmitic, myristic, lauric acids). A recent meta‐analysis of 60 intervention studies emphasized that, unlike palmitic acid, these trans monoenes increased the total‐to‐HDL‐cholesterol ratio; as a result these trans isomers could increase the cardiovascular risk more than lauric, myristic and palmitic acids. Data from four epidemiological cohort studies suggest that a 2% increase in energy of daily intake of trans fatty acids significantly increases the incidence of cardiovascular diseases. Concerning conjugated linoleic acids (CLA), to date, there are no epidemiological data. Current knowledge is based on intervention studies in humans and animals and on in vitro studies. For the mixture of isomers (__cis__9, __trans__11 and __trans__10, __cis__12), clinical studies gave inconsistent results, and results on animal models differed from one species to another. For each isomer studied separately, their effects on the lipoprotein profile in humans were different. However, no dose effect was found whatever the isomer. Studies performed in healthy subjects and obese men presented convergent conclusions regarding the detrimental effects of __trans__10,__cis__12 CLA, but with rumenic acid (__cis__9, __trans__11 CLA) positive effects were observed in healthy subjects, not in obese subjects &bockpls check!&bock. Finally, results of studies lead to attribute a potential, general proatherogenic effect to __trans__10, __cis__12 CLA.