More folic acid may raise prostate cancer risk
WASHINGTON - Men who take a folic acid supplement may be increasing their risk of getting prostate cancer, US researchers said yesterday.
A study showed that men who took a daily folic acid supplement were three times more likely to be diagnosed with prostate cancer over 10 years as men who took a placebo.
Folic acid helps the body make healthy new cells, and getting enough of it is crucial for women before and during pregnancy to prevent serious birth defects like spina bifida.
But previous research has provided conflicting evidence about folic acid and prostate cancer.
Jane Figueiredo of the University of Southern California and colleagues tracked 643 men who took either a folic acid supplement of one milligram daily or a placebo.
The men in the study who took the folic acid supplement had a 9.7 percent risk of being diagnosed with prostate cancer after 10 years, compared to a 3.3 percent risk for those taking a placebo, the researchers wrote in the Journal of the National Cancer Institute.
Judging prostate cancer risk was not the original purpose of the work. Data from the study previously showed that people taking folic acid supplements had a higher risk for polyps that could lead to colon cancer while aspirin cut the risk.
Folic acid, or folate, is a B vitamin found in foods such as leafy green vegetables, fruits, beans, peas, and nuts as well as in fortified cereals.
"We know that adequate folate levels are important in the prevention of several cancer types, cardiovascular, and neurological diseases," Figueiredo said in a statement.
"Adequate levels of folate may be beneficial, but too much folate is unlikely to be beneficial," she added.
Prostate cancer kills about 254,000 men a year globally, including about 29,000 in the United States. It is the second most commonly diagnosed cancer in men worldwide. 