Healthnotes Newswire (March 8, 2001)—A new study, published in the current issue of the Journal of the American Medical Association (JAMA), casts doubt on vitamin E’s reputation as an antioxidant for the masses.¹ Researchers at the University of Pennsylvania gave vitamin E supplements in varying amounts, or a matching placebo, to 30 healthy people for eight weeks and measured three indices of “oxidative stress” in their urine. Vitamin E did not appear to protect participants against damage from oxidation, regardless of the dose, leading the authors to question the rationale for vitamin E supplementation in healthy people.

Vitamin E is an antioxidant that has been shown in previous studies to protect cell membranes and other fat-soluble parts of the body, such as LDL cholesterol (the “bad” cholesterol). Hence, vitamin E is known as an antioxidant. Protection of LDL cholesterol may reduce the risk of heart disease. Oxidative stress appears to be a significant underlying factor in the development of a wide array of diseases, including atherosclerosis and cancer.

The results of the new study are somewhat inconsistent with the results of previous studies, in which vitamin E supplements have protected healthy people against oxidation.^{2 3 4 5} The reasons for the discrepancy are complex and not completely understood. Although many techniques exist for assessing the effects of antioxidants on oxidation in test tubes, it is difficult to meaningfully quantify the effects of supplements on oxidative stress in humans. For this reason, the results of the new study should be interpreted cautiously, and conclusions should be withheld pending further research. Moreover, this research had significant limitations, such as an extremely small study population—only five people were in each dose group.

Even if vitamin E does not possess the antioxidant capacity reported by other researchers, it does not necessarily mean the supplement cannot benefit healthy people. In the last ten years, the functions of vitamin E in the cell have been further clarified. In addition to antioxidant functions, vitamin E is now known to affect human health through other mechanisms, including direct effects on inflammation, blood cell regulation, connective tissue growth, and genetic control of cell division.⁶