A series of studies have lately shown that vitamins don’t reduce cancer risk. Just two weeks ago, researchers at the Brigham and Women’s Hospital of Harvard Medical School concluded that taking folic acid and other B vitamins on regular basis doesn’t prevent breast cancer or cancer in general.

In October, a trial of the National Cancer Institute involving about 35,000 men was halted after it was found that vitamin E and selenium didn’t prevent prostate cancer. On contrary, researchers found a higher risk for aggressive prostate cancer in participants taking only vitamin E and a small risk of developing diabetes in subjects taking only selenium.

An earlier study (of a much smaller group) conducted on the effect of selenium supplementation on the recurrence of skin cancers did not demonstrate a reduced rate of recurrence of skin cancers, but did show a reduced occurrence of total cancers.

Coming closer, a study released last week found that vitamin D supplements, taken at a dose of 400 international units per day, may not help prevent breast cancer in women after menopause.

Now, a new study funded by the National Institutes of Health and released Sunday at the American Association for Cancer Research conference in Washington, shows that vitamin C or E supplements do not help prevent cancer in men.

“After nearly 10 years of supplementation with either vitamin E or vitamin C, we found no evidence supporting the use of either supplement in the prevention of cancer. While vitamin E and C supplement use did not produce any protective benefits, they also did not cause any harm,” said Howard D. Sesso, Sc.D., M.P.H., an assistant professor of medicine at Brigham and Women's Hospital.

The study involved 14,641 male US doctors who took either 400 IU of vitamin E every other day or a placebo, or 500 milligrams of vitamin C daily or a placebo. Their average age was 64 at the start of the study and they were followed for eight years on average.

After the follow-up period, there were 1,929 cases of cancer, including 1,013 cases of prostate cancer, which many had hoped vitamin E would prevent. However, rates of prostate cancer and of total cancer were similar among all four groups. Overall, 490 men taking vitamin E developed prostate cancer compared to 523 in the placebo group.

“Well-conducted clinical trials such as this are rapidly closing the door on the hope that common vitamin supplements may protect against cancer. It’s still possible that some benefit exists for subgroups that couldn’t be measured, but the overall results are certainly discouraging,” said Marji McCullough, nutrition chief at the American Cancer Society.

Given the circumstance, people should not put all their hope in vitamins in order to prevent cancer. They should try to do things that are known to prevent the disease, such as having a healthy diet based mainly on vegetables and fruits, maintaining a healthy weight and exercising as much as possible, even if that involves only walking or cleaning the house. Staying active helps people maintain a balance in their life and get rid of daily stress, which can be extremely dangerous to their health.