Folic acid, vitamins don't prevent cancer

BOSTON, Nov. 5 (UPI) -- A daily supplement that included folic acid and vitamin B6 and B12 had no significant effect on the overall risk of cancer, U.S. researchers said.

Dr. Shumin M. Zhang of Brigham and Women's Hospital and Harvard Medical School, in Boston, and colleagues conducted a trial to evaluate the effect of combined folic acid, vitamin B6, and vitamin B12 treatment on cancer risk in women at high risk for cardiovascular disease.

The Women's Antioxidant and Folic Acid Cardiovascular Study included 5,442 U.S. female health professionals age 42 years or older, with pre-existing cardiovascular disease or three or more coronary risk factors, who were randomly assigned to receive either a daily combination of folic acid, vitamin B6 and vitamin B12 or a matching placebo.

They were treated for 7.3 years, from April 1998 through July 2005.

"A total of 379 women developed invasive cancer -- 187 in the active treatment group and 192 in the placebo group," the study authors said in a statement. "Compared with placebo, women receiving the active treatment had similar risk of developing total invasive cancer, breast cancer, or any cancer death."

The findings are published in the Journal of the American Medical Association.