Nutritional Strategies for Preventing Breast Cancer

In the past several years medical research has thrown more light on subjects that have been hinted at by observational studies showing decreased rates of cancer in various ethnic groups. Many cancer centers across the country are now recommending diets to prevent an initial tumor or recurrence of tumor along with other medical therapies. The suggestions made here are all supported by studies in the medical literature. There is good evidence to suggest that exposure to several carcinogens is involved in cancer promotion, so the strategy should be to limit exposure to these substances and also hasten their excretion from the body. In the case of breast cancer, it is apparent that estrogen plays a role in cancer promotion, and many of the strategies are designed to modify the estrogen effect on breast tissue.

  • Eat a high fiber diet—Fiber in the intestinal tract binds toxins, including hydroxylated estrogens, escorting them out of the body and decreasing their reabsorption. Try to eat at least 35 grams of fiber per day. Fiber supplements should be taken one hour before or two hours after nutritional supplements.
  • Exercise Regularly—Brisk exercise totaling at least four hours per week has been shown to decrease breast cancer risk by 37%.
  • Change your oil—Omega-3 fatty acids such as found in fish oils and flaxseed oils have been shown to decrease breast cancer risk in several studies. Conversely, Omega-6 fatty acids as found in polyunsaturated vegetable oils have been shown to increase the risk of breast cancer. The worst forms of vegetable oils are the partially hydrogenated or trans fats. These are found in margarine and solid vegetable shortening. Olive oil, as a monosaturated fat, is in the neutral category. However, it has also been shown to decrease the risk of breast cancer. (See separate sheet on fats and oils.)
  • Increase fresh fruits and vegetables—Hundreds of epidemiological and observational studies have demonstrated that the higher the intake of fruits and vegetables the lower the risk of many types of cancer including breast cancer. The most beneficial effect comes from eating nine servings per day. Cruciferous vegetables, which contain DIM (di-indolyl-methane) are especially beneficial. DIM can also be taken as a supplement, 300-500 mg. per day.
  • Avoid xenoestrogens—Our food supply is frequently contaminated with residues of hormone-like substances. These may have been given to animals to promote growth or used as pesticides in growing crops. They are also found in plastics which can contaminate food or fluids. Invest in a good water filter.
  • Eat flax—Flaxseed contains both the healthy Omega-3 fats and a weak estrogen which blocks estrogen receptor sites. Studies are now emerging showing dramatic results from increased flaxseed intake. Grind the flaxseed in a coffee grinder just before using to obtain the best benefit.
  • Lower insulin levels and reduce body fat—High insulin levels potentiate the effect of estrogen in breast tissue. Insulin is triggered by eating high glycemic food, i.e. refined carbohydrates. Eating high fiber foods slows absorption and keeps insulin levels lower and stable.
  • Take antioxidant supplements—Many antioxidants have been shown to decrease cancer risk. These include vitamins C and E (mixed tocopherols), selenium, alpha-lipoic acid and the carotenoids, which include alpha and beta carotene and lycopene. Vitamin D has also been shown to reduce breast cancer risk. Take 3,000 to 10,000 IU per day, shooting for a blood level greater than 60.
  • Avoid alcohol—Many studies show an increasing risk of breast cancer correlates with an increasing alcohol consumption.

Dianne Farley-Jones, M.D.

*The information on these documents available on the Alpine Clinic web site are not intended take the place of a consultation with a licensed physician. These are strictly intended for educational purposes, and should not be used to diagnose, cure, prescribe or treat any specific disease.