Vegetables and lower breast cancer risk

Cruciferous vegetables may help lower the risk of developing breast cancer, particularly for women who carry a particular gene variant linked to the disease.

American researchers studied more than 6,000 women and found that those with the highest intake of cabbage and white turnips had a somewhat lower risk of postmenopausal breast cancer than those with the lowest intake. The findings add to evidence that compounds in cruciferous vegetables may help fight cancer. Cabbage, white turnips, broccoli, cauliflower and kale contain certain compounds that the body converts into substances called isothiocyanates, which are thought to have anti-cancer effects.

High consumption of cabbage and white turnips were linked to a moderately lower breast cancer risk. But the apparent benefit was stronger among women who carried two copies of a particular variant of a gene called GSTP1. Among these women, those with the highest intake of any cruciferous vegetables had about half the risk of breast cancer as those who ate the fewest.

GSTP1 is an enzyme that helps detoxify the body of potentially cancer-causing substances. Some studies have suggested that having a particular form of the gene - the Val variant - may raise a woman's risk of breast cancer. The current study found that women who carried two copies of the Val variant did, in fact, have a higher risk of developing breast cancer before menopause than women who had other variants in the GSTP1 gene. But the excess risk was cut substantially in those who ate the most cruciferous vegetables.

It's possible that people who carry two Val variants of the GSTP1 gene excrete the beneficial isothiocyanates more quickly, and eating more cruciferous vegetables helps counter this. However, more research is needed to better understand how cruciferous vegetables might modify breast cancer risk.