Vitamin E linked to 17 percent boost in prostate cancer risk
In a large study, researchers found a 17 percent increased risk of prostate cancer linked to taking vitamin E. The finding follows research showing use of vitamin supplements is linked to higher death rates in older women.
Vitamin E might lead to higher rates of prostate cancer
In the study, researchers looked at prostate cancer risk among 35,533 men from 427 study cites in the United States, Canada, and Puerto Rico.
Between August 2001 and June 2004, the men received either selenium (200 micrograms/day); vitamin E (400 IU/day); both agents; and placebo.
Eric A. Klein, M.D., of the Cleveland Clinic, and colleagues followed the men through July 5, 2011.
At the start of the study, healthy men received a prostate exam, a rectal exam to check prostate size. Black men included in the study were over age 50. Other men included were over age 55. To be included in the study, PSA had to be below a certain level,
The study is a follow-up from the Selenium and Vitamin E Cancer Prevention Trial SELECT trial, published in December 2008 that found no benefit for using the supplements to reduce prostate cancer risk.
In the original SELECT trial, prostate cancer risk was slightly, but insignificantly higher from vitamin E.
The results of the ongoing investigaton showed prostate cancer rates were 17 percent higher for men taking vitamin E. Compared to the men give placebo, the rates were also higher, but the only statistical significant link to cancer was in the vitamin E group.
The authors write, "Lifetime risk of prostate cancer in the United States is currently estimated to be 16 percent. Although most cases are found at an early, curable stage, treatment is costly and urinary, sexual, and bowel-related adverse effects are common."
Additional prostate cancer cases found after initial study
Following the original finding, there have been an additional 521 men diagnosed with prostate cancer – 147 in the vitamin E group, 143 in the group taking selenium, 118 new diagnoses in the combination vitamin E/selenium group and just 13 new cases among men given placebo.
Dr. Klein and his team say the higher risk of prostate cancer linked to vitamin E is "an important public health concern.” More than half of older men may be taking some form of vitamin E in hopes of preventing prostate cancer or coronary artery disease.
Vitamin E is an antioxidant found naturally in some foods and added to others. The study is another blow to the health benefits of vitamin supplements. Taking a supplement may not provide the same benefits as getting nutrients from whole foods that work in synergy for optimal cellular functioning.
The current study links higher risk of prostate cancer to vitamin E supplements. Multi vitamins contain lower doses than those used in the study.