STUDY: People taking vitamin E supplements for at least 10 years were less likely to die from bladder cancer.

JOURNAL: Am J Epidemiol 2002;156:1002-1010

AUTHORS: Dr. Jacob

ABSTRACT: People who take vitamin E regularly are less likely than those in the general population to die of bladder cancer, researchers report, but it is not clear if the vitamin itself or some lifestyle factor is responsible for the reduced risk.

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COMMENTARY: Researchers tracked nearly 1 million US adults for 16 years and interviewed them about their diet. Those who reported taking vitamin E supplements for at least 10 years were less likely to die from bladder cancer, compared with adults who reported shorter durations of use.

In contrast, there was no association between regular vitamin C use and bladder cancer mortality, report researchers in the December issue of the American Journal of Epidemiology.

The current findings support those of two previous studies that showed an inverse relationship between bladder cancer risk and vitamin E intake.

Exactly how vitamin E may protect against bladder cancer is unclear. It might result from its antioxidant effect in neutralizing DNA-damaging free radicals. Alternatively, vitamin E may boost the immune system or prevent the formation of carcinogenic nitrosamines.

However, if vitamin E's antioxidant properties are responsible for the protective effect, it is not clear why vitamin C use confers no protection against the malignancy.

Dr. Jacob emphasized that further studies are needed to verify the current results and to possibly shed light on vitamin E's mechanism of action.