Daily Calcium and Multivitamin May Cut Cancer Risk

By Megan Tempest in Food on Apr 22, 2010 3:40PM

www.webmd.com

Results of a new study show that women who take calcium supplements and a multivitamin have reduced breast cancer risk. The findings were presented last Saturday to the America Association of Cancer Research in Washington by researchers at Ponce School of Medicine in Puerto Rico. The study analyzed 744 women, including 278 with breast cancer and 466 healthy controls, using blood tests and questionnaires about dietary intake of specific vitamins and minerals. The women taking calcium supplements had a 40% reduced risk of breast cancer, while those taking a multivitamin showed a 30% reduced risk. "We found that taking multivitamins and calcium supplements were strongly protective against breast cancer," said Dr. Manuel Bayona, a professor in the public health program at the Ponce School of Medicine. "Which vitamins exactly? We don't know because they were multivitamins." According to study co-author Dr. Jaime Matta, a professor of pharmacology, physiology and toxicology, “It's possible that the vitamins work better together than individually."

Why the greater reduction in risk from calcium? According to the researchers, calcium has a “DNA repair capacity” - the biological process by which our cells repair damaged DNA that may otherwise cause cancer. Previous studies have shown calcium’s apparent cancer-reducing benefit, however have not isolated the mechanism of action. "We've known that DNA repair capacity is linked to several other types of cancer," said Dr. Matta, "DNA repair capacity is very, very linked to breast cancer risk."

The study is likely to spark further research. "The totality of the evidence to date does not support taking vitamins and calcium for breast cancer prevention," said Marji McCullough, strategic director of nutritional epidemiology for the American Cancer Society. "There are other reasons women may wish to take calcium, for example for bone health."