Consumption and health effects of trans fatty acids: a review

Consumption of industrially produced trans fatty acids (TFA) remains high in many populations, particularly in developing nations where partially hydrogenated vegetable oils are frequently used for home cooking and among individuals in developed countries having high intakes of bakery or processed foods. Well-controlled observational studies and randomized trials indicate that TFA consumption adversely affects multiple risk factors for chronic diseases, including numerous blood lipids and lipoproteins, systemic inflammation, endothelial dysfunction, and possibly insulin resistance, diabetes, and adiposity. Growing evidence for the latter effects is particularly concerning given the worldwide obesity pandemic and high contents of industrially produced TFA in many foods marketed toward children. Consistent evidence from prospective observational studies of habitual TFA consumption and retrospective observational studies using TFA biomarkers indicates that TFA consumption increases risk of clinical coronary heart disease (CHD). Based on the adverse effects of risk factors and consistent relationships with clinical endpoints, the evidence that TFA consumption increases CHD risk is convincing. Some evidence suggests that TFA consumption may also increase other disease outcomes, but further investigation is needed to confirm the presence and magnitude of such effects. More research is also needed to understand how specific TFA isomers of varying chain length and double bond location may affect different biologic pathways of disease. Both individual- and policy-level initiatives to decrease TFA consumption should continue, particularly in population subgroups and in developing nations with high consumption of partially hydrogenated vegetable oils.