Vitamin E and colon cancer: is there an association?

The role of vitamin E in the etiology and prevention of colon cancer is not clear. It is possible that various forms of vitamin E may act differently in colon tissue and may be effective chemopreventive agents. Previous reports of vitamin E and colon cancer have focused on alpha-tocopherol and have not considered other dietary forms of vitamin E. Data from a study of 1,993 cases and 2,410 controls were used to evaluate the associations between the four most common forms of dietary vitamin E and supplemental vitamin E and colon cancer. After adjusting for other health and life-style factors, we did not observe a statistically significant association between dietary tocopherols and colon cancer. There were, however, suggestions of an inverse association between total alpha-tocopherol equivalents and colon cancer among women diagnosed with colon cancer before the median age of the control population, 67 years [odds ratio (OR) = 0.66, 95% confidence interval (CI) = 0.36-1.22] and a direct association between gamma-tocopherol and colon cancer among these women (OR = 1.44, 95% CI = 0.92-1.93). Women diagnosed with colon cancer when > or = 67 years of age appeared to have some protection from use of vitamin E supplements (OR = 0.80, 95% CI = 0.56-1.15). These data offer only limited support for a protective effect of vitamin E and colon cancer after adjustment for other health and life-style factors.