The potential role of antioxidants in metabolic syndrome.

Metabolic syndrome (MS) is a constellation of risk factors that raise the risk for heart disease and other health problems, such as obesity. The clustering of metabolic abnormality is closely related to oxidative stress and inflammation, as well as the progression of atherosclerosis. Antioxidants are reducing agents which inhibit the oxidation of other molecules and can be used not only to prevent but also to treat health complications of MS and atherosclerosis. They can be ingested in the normal diet, since they are found in many food sources, or in supplement formulations. Herein, we aim to review the literature concerning the effect of antioxidants on MS. We focus on antioxidants with some evidence of action on this condition, like flavonoids, arginine, vitamin C, vitamin E, carotenoids, resveratrol and selenium. Experimental and clinical studies show that most of the above-mentioned antioxidants exhibit a wide range of effects in protecting the human body, especially in MS patients. However, the underlying mechanisms are not fully elucidated for most of these compounds. Also, some of them should be used with caution because their excess can be toxic to the body. In general, antioxidants (especially those present in foods) can be used by MS individuals because of their direct effect on oxidative stress. Additionally, they should be encouraged as part of a nutritional lifestyle change, since this is part of the therapy for all diseases involved in metabolic disorders.