High vitamin E supplement intake does not protect against cancer

06/04/05 Taking high-dose vitamin E supplements for an extended period doesn't protect against cancer; in fact, it may even speed up the development of latent cancers, according to a study by researchers from Hotel-Dieu de Quebec Research Centre and Universite Laval. Their results are published in the April issue of the prestigious Journal of the National Cancer Institute.

Dr. Isabelle Bairati, professor at the Universite Laval Faculty of Medicine and researcher at Hotel-Dieu de Quebec's Oncology Research Centre, and colleagues conducted the study among 540 volunteers over an eight-year period. All the participants were treated for early stage head and neck cancer and were at high risk of developing another cancer. During the first three years, half of the participants received 400 international units of vitamin E daily, while the rest were given a placebo.

Researchers put forth an initial hypothesis that people who eat a lot of fruits and vegetables are less likely to develop cancer. This beneficial effect might come from the many antioxidant vitamins contained in those types of foods. Dr. Bairati and her colleagues thus decided to analyze the impact of vitamin E intake, in the form of a daily food supplement, among a population at high risk of developing a second cancer.

Dr. Bairati's study was approved and funded by the National Cancer Institute of Canada. It was also approved by Health Canada and ethics committees from each of the participating hospitals.