Breast Cancer Risk and Diet/Exercise

Breast cancer is the most common cancer and the top cancer killer in women who do not smoke. This is the case for most other modern countries where a diet high in fat, refined carbohydrates and fattened domestic animals is the norm.

Consider that:• Breast cancer rates are much lower in countries where women are active and eat a low-fat, high-fiber diet.• In most modern countries, breast cancer incidence continues to increase after menopause but in developing countries, it falls.1• Breast cancer increases when women from low-breast-cancer-risk countries move to Westernized countries.The level of estrogen in the blood after menopause is typically higher in overweight women than in thinner women. Weight gain leads to insulin resistance, higher insulin levels, and an increase in insulin-like growth factor-1 (IGF-1). More body fat leads fat cells to make more adipokines and cytokines that may promote the growth of breast cancer as well.2A study by researchers at UCLA examined the impact of the Pritikin Program on the levels of hormones and other blood markers associated with the promotion of breast cancer. The subjects were 38 overweight, obese postmenopausal women ages 51-79. The women consumed a low-fat (10-15% of calories), high-fiber diet ad libitum and exercised daily for 13 days. No alcohol was permitted. Blood was taken on day #1 and again on day #13. After 12 days on the Pritikin diet and exercise program, serum estrogen levels dropped by more than one third. Other hormonal factors associated with an increased risk of breast cancer were also significantly reduced. An in-vitro study of breast cancer cells revealed stunted growth and increased cancer cell death when the serum was from women following the Pritikin Program compared to before they started it. The authors concluded, “These results show that a very-low-fat, high fiber diet, combined with daily exercise, results in major reductions in risk factors for breast cancer…” “The results suggest a significant reduction in the risk for breast cancer or for breast cancer recurrence.”3By James J. Kenney, PhD, RD, FACN1 Epidemiol Rev 1993;15:17-352 Cancer 2004;100:694-7003 Nutr and Cancer 2006;55:28-34