Broccoli, cauliflower and cabbage help repair damaged DNA

Need another reason to eat your vegetables? New research shows that some of them contain chemicals that appear to enhance DNA repair in cells, which could lead to protection against cancer development, say Georgetown University Medical Center researchers.

In a study published in the British Journal of Cancer, the researchers show that in laboratory tests, a compound called indole-3-carinol (I3C), found in broccoli, cauliflower and cabbage, and a chemical called genistein, found in soy beans, can increase the levels of BRCA1 and BRCA2 proteins that repair damaged DNA.

Although the health benefits of eating your vegetables--especially cruciferous ones, such as broccoli--aren't particularly new, this study is one of the first to provide a molecular explanation as to how eating vegetables could cut a person's risk of developing cancer, an association that some population studies have found, says the study's senior author, Eliot M. Rosen, MD, PhD, professor of oncology, cell biology, and radiation medicine at Georgetown's Lombardi Comprehensive Cancer Center.

"It is now clear that the function of crucial cancer genes can be influenced by compounds in the things we eat," Rosen says. "Our findings suggest a clear molecular process that would explain the connection between diet and cancer prevention."

In this study, Rosen exposed breast and prostate cancer cells to increasing doses of 13C and genistein, and found that these chemicals boosted production of BRCA1, as well as its sister repair protein, BRCA2.

Mutations in either of these genes can lead to development of breast, prostate and ovarian cancers.

Since decreased amounts of the BRCA proteins are seen in cancer cells, higher levels might prevent cancer from developing, Rosen says, adding that the ability of I3C and genistein to increase production of BRCA proteins could explain their protective effects.