By Jennifer Reilly, R.D., and Neal D. Barnard, M.D.
Red Meat Increases Breast Cancer Risk
New data from Harvard’s Nurses’ Health Study II show that women who consumed one and a half or more servings of red meat per day had nearly double the risk of developing hormone receptor-positive breast cancer compared with women consuming three or fewer servings of red meat per week. Hormone receptor-positive breast cancer is the most common type of breast cancer and has been on the rise in recent years. This study involved more than 90,000 premenopausal women age 26 to 46 who completed food surveys during a 12-year period. Animal fat and red meat intake were found to increase premenopausal breast cancer risk in a previous analysis of the Nurses’ Health Study II. Possible reasons for this association include carcinogens produced as meat is cooked, hormones given to cattle for growth promotion, red meat’s high content of heme iron, which has been shown to increase estrogen-dependent tumor growth, and red meat’s high fat content.
Cho E, Chen WY, Hunter DJ, Stampfer MJ, Colditz GA, Hankinson SE, Willett WC. Red meat intake and risk of breast cancer among premenopausal women. Arch Intern Med. 2006;166:2253-2259.
Diabetes May Increase Cancer Risk
Nearly 98,000 Japanese men and women enrolled in the Japan Public Health Center-Based Prospective Study were studied to determine a possible connection between diabetes and cancer risk. Men with a history of diabetes had a 27 percent increased risk of developing cancer compared with men without a history of diabetes. The connection was especially strong among men for cancers of the liver, pancreas, and kidney, and connections were also seen for cancers of the colon and stomach. In women, a borderline significant 21 percent increase in cancer risk was found when there was a history of diabetes. Significant connections were seen in particular for stomach and liver cancer. Researchers theorize that excess insulin produced in diabetes may encourage the growth of cancer cells.
Inoue M, Iwasaki M, Otani T, Sasazuki S, Noda M, Tsugane S. Diabetes mellitus and the risk of cancer: results from a large-scale population-based cohort study in Japan. Arch Intern Med. 2006;166:1871-1877.
Obesity Decreases Ovarian Cancer Survival
The medical records from Cedars Sinai Medical Center of 216 women with ovarian cancer have linked body weight and ovarian cancer. Obese women were more likely to have a more aggressive type of ovarian cancer and were more likely to have the cancer recur earlier after treatment and die sooner than women of ideal body weight. Fat tissue produces estrogens, which can fuel the growth of some forms of cancer. Ovarian cancer affects nearly 1 in 60 women and is often not detected until it is in an advanced stage. Seventy percent of ovarian cancer patients die within five years of diagnosis, making it one of the most deadly forms of the disease. Maintaining a healthy weight is crucial for the prevention and survival of many forms of cancer.
Pavelka JC, Brown RS, Karlan BY, Cass I, Leuchter RS, Lagasse LD, Li AJ. Effect of obesity on survival in epithelial ovarian cancer. Cancer. 2006;107:1520-1524.
The Cancer Project is a nonprofit PCRM subsidiary that advances cancer prevention and survival through nutrition education and research.