Beta-Carotene, Vitamins C, E Fail to Cut Cancer Risk

BOSTON—A new study from researchers at Brigham and Women’s Hospital show that supplemental vitamins C and E, and beta-carotene, fail to provide protection against cancer for middle- aged women. In this study, women who took beta-carotene,  vitamin C or E, or a combination of the supplements had a similar risk of cancer as women who did not take the supplements. The research was published online in the Journal of the National Cancer Institute.

“Our finding is what is called a null result, meaning that no benefit was found from supplementation,” said Jennifer Lin, PhD, a researcher at Brigham and Women’s Hospital and lead author of the study. “However, this finding and other similar ones are still important not only because many Americans take vitamin supplements with belief that they are obtaining some benefit, but also because these findings help to shed light on both the causes of cancer and the prevention of it.”

Previous research suggests that people whose diets are high in fruits and vegetables, and thus antioxidants, may have a lower risk of cancer; however, results from previous randomized trials that address the issue rarely supported that observation. “Our study is another case where vitamin supplements failed to prevent against cancer,” Lin said.

Lin and colleagues tested the impact of antioxidant supplements on the development of cancer in 8,171 women who were at high risk of cardiovascular disease. The women were randomly assigned to take vitamin C, vitamin E or beta-carotene. After following the women for an average of 9.4 years, there was no benefit from taking the supplements compared with placebo in terms of the development of cancer or death from cancer.