Food & Breast Cancer
A recent study in the JADA examined the association between foods and oxidative DNA damage [djuric Z et al JADA 1998;98-524]. If confirmed by larger studies, these results would suggest that specific dietary changes to reduce oxidative DNA damage could possibly reduce the risk of breast cancer. Specifically, this study showed that fatty meats were associated with more DNA damage whereas the women who consumed more cooked vegetables had less DNA damage. It is important to note that this study was conducted using foods and not antioxidant food supplements.It is already well established that a diet higher in fruits and vegetables and lower in fatty meats is likely to reduce many types of cancer, including breast cancer [Willett W Am J Clin Nutr 1994;59:1162S]. Djuric’s study suggests that protection against oxidative stress could also play a role. Additionally, women who eat more fruits and vegetables and less fatty foods usually gain less weight over time. A weight gain of 22 pounds in adulthood was recently found to be significantly associated with breast cancer in postmenopausal women [Huang Z et al JAMA 1997;278:1407]. Weight gain likely increases breast cancer because it elevates estradiol levels after menopause. Higher levels of estradiol throughout life are a well established risk factor for breast cancer. This may be one reason that early menarche and delayed birth of the first child increase the risk of breast cancer.Alcohol consumption also generates free radicals in the body and is a risk factor for developing breast cancer [Schatzkin A et al N Engl J Med 1987;316:1169]. However, alcohol also elevates estrogen levels so it is not clear which mechanism is more important in the development of breast cancer.The bottom line: A lowfat plant-based diet with plenty of fruits and vegetables, limited alcohol and regular exercise will likely help prevent breast cancer by reducing oxidative DNA damage and excessive estrogen levels.• Dr. Jay Kenney, PhD, RD, is a Nutrition Research Specialist at the Pritikin Longevity Center and on the Board of Directors for the National Council Against Health Fraud.
