Cruciferous vegetables may reduce breast cancer risk

A diet high in cruciferous vegetables may reduce breast cancer risk, and it may modify the effects of genetic predisposition to the disease, according to a report published in the March issue of the American Journal of Clinical Nutrition.

Sang-Ah Lee, PhD, of Vanderbilt University Medical Center in Nashville, TN, and colleagues conducted a study of 3,035 women with breast cancer and 3,037 controls to look at the effect of intake of cruciferous vegetables and the GSTP1 Ile105Val genetic polymorphism on the risk of breast cancer.

Women with the GSTP1 Val/Val genotype, particularly those who were premenopausal, had a significantly higher risk of breast cancer, the investigators found. Women who ate greater amounts of turnip and Chinese cabbage than the other subjects had a lower risk of postmenopausal breast cancer. The risk of breast cancer was 1.74 times higher in women with the GSTP1 Val/Val genotype and low cruciferous vegetable intake compared to women with the Ile/Ile or Ile/Val genotype, an effect primarily seen in premenopausal women (OR, 2.08).

"The cancer-preventive potential of cruciferous vegetable is believed to derive, in part, from the effects of isothiocyanates and other glucosinolate derivatives on phase II enzyme activity," the authors write. They further postulate the data "may suggest that a genetic predisposition to breast cancer related to GSTP1 genotype could be modified by cruciferous vegetable intake." Vegetables in the cruciferous family, in addition to cabbage, include broccoli, cauliflower, and brussels sprouts.

Lee SA, Fowke JH, Lu W, et al. Cruciferous vegetables, the GSTP1 Ile105Val genetic polymorphism, and breast cancer risk. Am J Clin Nutr. 2008;87:753-76..