Alpha-tocopherol Vitamin E May Slash Lung Cancer Risk
Lee Swanson Research Update
ncreasing intakes of vitamin E may decrease the risk of lung cancer by over 50%, according to a new study. Researchers from the University of Texas M.D. Anderson Cancer Center report that intakes of vitamin E in the alpha-tocopherol form were associated with consistent and independent reductions in lung cancer risk.
"To the best of our knowledge, this is the first study to compare dietary intakes of the different forms of tocopherols (alpha-, beta-, gamma- and delta-tocopherol) and lung cancer risk," wrote lead author Somdat Mahabir in the International Journal of Cancer.
There are eight forms of vitamin E: four tocopherols (alpha-, beta-, gamma- and delta-) and four tocotrienols (alpha-, beta-, gamma- and delta-). Alpha-tocopherol is the main source found in supplements and in the European diet, while gamma-tocopherol is the most common form in the American diet.
Mahabir and co-workers report results from an ongoing study involving 1,088 patients with lung cancer (average age 61.7) and 1,414 healthy controls (average age 60.8). Demographic and lifestyle data were collected, including smoking habits.
The researchers calculated that the highest average intakes of alpha-tocopherol (more than 7.73 mg per day) were associated with a 53% reduction in lung cancer risk, compared to the lowest average intakes (less than 4.13 mg per day). This result took into account the other forms of tocopherols, which showed no significant associations on lung cancer risk.
Considering all the tocopherols together, the highest average intake (more than 12.95 mg per day) was associated with a 55% reduction in the risk of lung cancer, compared to the lowest average intakes (less than 6.68 mg per day), said the researchers.
"We found consistent independent associations for increased dietary alpha-tocopherol intake and risk reduction but did not find independent associations for gamma-, beta- and delta-tocopherol in lung cancer risk," wrote Mahabir. "Our data should be useful in stimulating additional epidemiologic and basic science research in the relationship of different forms of vitamin E and cancer."
International Journal of Cancer 123(5):1173-1180, 2008