Antioxidants fail again in cancer prevention study

By Will Dunham

WASHINGTON (Reuters) - Beta carotene, vitamin C and vitamin E supplements taken for years failed to lower overall cancer risk in the latest study to cast doubt on the possibility that such dietary supplements can prevent cancer.

The findings, published on Tuesday in the Journal of the National Cancer Institute, followed two other important studies that also did not show that various antioxidant supplements could prevent cancer.

“Although a healthful dietary pattern rich in fruits and vegetables may lower cancer risk, such benefits cannot be mimicked by simply popping a few vitamin supplements,” Dr. JoAnn Manson of Brigham and Women’s Hospital and Harvard Medical School in Boston said in a statement.

Manson, Jennifer Lin and colleagues tracked 7,627 women who were an average 60 years old at the start of the study, who took supplements for about 9-1/2 years.

Some took 500 milligrams of vitamin C daily, 600 IU (international units) of vitamin E every other day or 50 milligrams of beta carotene every other day — or various combinations of the three supplements. Others were given placebos.

Women who took the supplements had similar rates of cancer and cancer death compared to those who took a placebo, the researchers said. The study suggested that vitamin E supplements might reduce colon cancer risk and that beta carotene supplements might modestly raise lung cancer risk.

The researchers, however, acknowledged that while the women took the supplements for almost a decade, the study “may still be of insufficient duration to assess effects on cancer incidence, given the long latency for cancer.”

“Simply taking antioxidant supplements is insufficient to prevent cancer. People should take more natural plant foods which are rich with many nutrients including but not limited to antioxidants,” Lin said by e-mail.

Beta carotene, vitamin E and vitamin C are antioxidants thought to protect against damage caused by free radicals, substances that can harm cells, tissues and organs.

Fruits and vegetables are rich in these vitamins, and it has been shown that people who eat plenty of these foods have a lower risk of heart disease, cancer and other conditions.

The Council for Responsible Nutrition, a dietary supplement industry group, found fault with the study.

Andrew Shao, the group’s vice president for scientific and regulatory affairs, noted in a telephone interview that the women in the study all were at high risk for heart disease, and the study’s original design was to assess whether the supplements protected against cardiovascular illness.

“Supplements are just one tool that people need to incorporate into their lifestyle to stay healthy. We can’t expect just to take supplements and that’s going to prevent cancer. That simply isn’t the way it works,” Shao added.

In a study released in November involving about 15,000 male doctors, vitamin E and C supplements did not lower cancer risk. Another study released in October found no cancer reduction in 35,000 men taking vitamin E and selenium supplements.

(Editing by Maggie Fox and Vicki Allen)


Related Posts:

NEW YORK (Reuters Health) - In the large Women’s Antioxidant Cardiovascular Study, participants who took beta carotene, vitamin C, vitamin E, or a combination of supplements had no significant reductions in their risk of cancer. The clinical trial, which involved 7,627 women who were followed for an average of 9.4 years, was conducted by Dr. Jennifer

Full Post: No cancer risk reductions seen with antioxidants

WASHINGTON (Reuters) - Certain breast cancer survivors who load up on fruits and vegetables, eating far more than current U.S. guidelines, can slash their risk the tumors will come back by nearly a third, according to a U.S. study released on Monday. The finding only held for women who did not have hot flashes after their

Full Post: Fruits, veggies slash breast cancer risk: U.S. study

By Joene Hendry NEW YORK (Reuters Health) - A study in young adult women links high blood levels of vitamin C with lower blood pressure. This “strongly suggests that vitamin C is specifically important in maintaining a healthy blood pressure,” lead author Dr. Gladys Block, of the University of California, Berkeley, told Reuters Health. Previous research linked high

Full Post: High vitamin C linked to lower BP in young women

WASHINGTON (Reuters) - Neither vitamin C nor vitamin E supplements cuts the risk of cardiovascular disease including heart attack and stroke in a U.S. study published on Sunday. And a second study failed to show that taking low-dose aspirin helped prevent heart and artery disease among Japanese people with diabetes. Many people take vitamin supplements to try

Full Post: Vitamins C, E do not cut heart attack, stroke risk: study

By Amy Norton NEW YORK (Reuters Health) - Women with early-stage breast cancer may live longer if they maintain a diet rich in fruits, vegetables, whole grains and low-fat dairy, a new study suggests. This so-called “prudent” diet was not linked to a lower risk of death from breast cancer specifically. However, researchers found, breast cancer patients

Full Post: Diet tied to survival in breast cancer patients

Site Navigation

Most Read