ARS | Publication request: Does gamma-tocopherol play a role in the primary prevention of heart disease and cancer? A review

Submitted to: Journal of the American College of Nutrition
Publication Type: Review Article
Publication Acceptance Date: June 1, 2006
Publication Date: August 1, 2006
Citation: Dietrich, M., Traber, M.G., Jacques, P., Cross, C.E., Hu, Y., Block, G. 2006. Does gamma-tocopherol play a role in the primary prevention of heart disease and cancer? A review. Journal of the American College of Nutrition. 25(4): 292-299.

Technical Abstract: Gamma-tocopherol is a form of vitamin E that has recently received more research attention based on results from in vitro and animal studies regarding its antioxidant and anti-inflammatory properties. Vitamin E consists of a group of eight isomers, four tocopherols (alpha-, beta-, gamma-, delta-tocopherol) and four tocotrienols (alpha-, beta-, gamma-, delta-tocotrienol). Within the vitamin E group, alpha-tocopherol is the predominant form in plasma and tissue and it therefore has been studied extensively in in vitro and in vivo studies. Recent in vitro and animal studies suggest that the antioxidant properties of gamma-tocopherol may actually exceed those of alpha-tocopherol and also suggest that gamma-tocopherol has anti-inflammatory properties. As both cardiovascular disease and many cancers have been associated with inflammation and/or evidences of oxidative stress, and as aforementioned data suggests a role for gamma-tocopherol in the amelioration of both processes, we explored the literature for associations between dietary intake or plasma levels of gamma-tocopherol and the risk of human cardiovascular disease and cancer. Only very limited data is available on the association of plasma gamma-tocopherol concentrations with stroke and CHD death, providing no evidence of a protective effect of gamma-tocopherol. With regard to cancer, data from plasma studies is suggestive of a protective effect of gamma-tocopherol. However, this finding can only be applied to men since the majority of these cancer studies investigated prostate cancer. Studies of CHD events and stroke using dietary vitamin E as a proxy for gamma-tocopherol intake show inconclusive results and are still too limited. Nonetheless, the potential anti-inflammatory effects of gamma-tocopherol remain of great interest and a possible protective effect of dietary vitamin E, thus gamma-tocopherol can not be dismissed at this time. In order to better understand the potential role of gamma-tocopherol in chronic disease, more well-designed epidemiologic and intervention studies, with measurement of plasma gamma-tocopherol and explicit estimates of dietary gamma-tocopherol, are needed.