Human clinical trials have shown that fish oils reduce the risk of a variety of disorders including CVD. Despite this, results have been inconsistent. Fish oils are easily oxidised and some fish oils contain higher than recommended levels of oxidised products, but their effects have not been investigated. Recent evidence indicates that dietary oxidised fats can contribute to the development of atherosclerosis and thrombosis. This review summarises findings from cellular, animal and human trials that have examined the effects of oxidised lipids and their potential to affect health outcomes, and proposes that oxidised products in fish oils may attenuate their beneficial effects. More research is required to determine the magnitude of negative effects of fish oil on health outcomes in clinical trials.
