The Potential Physiological Role of γ-Tocopherol in Human Health: A Qualitative Review

Chronic aging-related diseases result in the greatest burden to the health care system, yet there is little agreement on optimal levels of vitamins or the functional significance of many other dietary molecules in disease prevention. This review presents accumulated information regarding the role of gamma-tocopherol in the prevention of nitrogen oxide-mediated damage and its impact on aging-related diseases. gamma-Tocopherol is ubiquitous in the diet and levels appear to be physiologically regulated such that levels rise in response to inflammation and deficiencies in certain key vitamins. The unique antioxidant properties of gamma-tocopherol, whereby DNA-damaging nitrogen dioxide is rapidly converted to nitric oxide, suggest a mechanistic justification for a functional role in the prevention of DNA damage over time. Data from cell, animal, and human studies indicate that gamma-tocopherol appears to have significant beneficial effects, protecting cells from inflammatory damage; however, interpretation of epidemiologic studies is complex due to the paradoxical rise in levels of gamma-tocopherol in response to known etiologic risk factors. Current knowledge of its antioxidant mechanism of action, apparent physiological regulation, and impact on various enzymatic pathways suggests gamma-tocopherol may have a functional role in maintaining human health. Its utility as a biomarker and the consequences of its deficiency deserve further study.