Breast Cancer Prevention (cont.)

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Are there other breast cancer prevention measures?


Antioxidants are chemicals that prevent a type of chemical reaction called oxidation. Oxidation is a major source of free radical formation. Antioxidants also mop up the free radicals that are formed.

Free radicals are electrically charged chemicals that can attack and damage proteins and DNA, thereby altering genetic information. If enough damage occurs to the DNA segments of a cell that controls cell division and growth, cancer can develop from that single cell. Free radicals can be formed by the normal metabolic activity in the body. However, there is no evidence that dietary intake of antioxidants affects breast cancer risk. 

Dietary fats

Early epidemiological studies suggested that high-fat diets might be associated with increased risks of breast cancer. But this relationship has not been confirmed, and results of studies have been mixed. Furthermore, it is clear that some fats may be protective rather than harmful. There are, however, some theoretical concerns about eating overcooked meats and fats.

Diet and lifestyle measures to reduce breast cancer risk

Theoretically, there are dietary and lifestyle measures that can decrease free-radical formation and reduce the risk of developing breast and other types of cancer. These measures include

  • diets rich in vegetables and fruits;
  • diets low in fats, and red and overcooked meats;
  • reasonable intake of antioxidants, such as vitamins E and C; and
  • regular exercise and weight control.

Evidence that these measures reduce the chances of developing breast cancer is largely based on epidemiological data. Epidemiological evidence is derived from comparing two large populations with similar characteristics that have different diets or levels of exercise. Epidemiological evidence can only be suggestive, not conclusive. In fact, concrete proof that diet and exercise actually reduce the risk of developing breast cancer will be difficult to attain, and there is no evidence that any breast cancer prevention diet exists.

When firm scientific data is lacking and is unlikely to be available for the foreseeable future, the doctor has to weigh the risks of his/her recommendations against the potential benefits. Long-term risk and benefit considerations are especially important in advising young, healthy women about preventing a disease that they may or may not develop.

In the case of diets low in fat and overcooked meats, diets high in vegetables and fruits, avoiding smoking, and regular exercise, there is enough known benefit and very little known risk, which makes it easy for doctors to recommend them to their patients.

Doctors are also comfortable with recommending one multivitamin a day. However, there is no clinical evidence that taking megadoses of vitamins are of any benefit. Megadoses of certain vitamins can have adverse side effects.


There is epidemiological data which show that women who exercise regularly have a lower incidence of breast cancer than women who do not exercise. The reason for such a benefit is unknown, but it may be related to the fact that obese individuals have higher levels of estrogen in the body than people who are not obese. The higher levels of estrogen may increase the risk of breast cancer in obese women.

Medically Reviewed by a Doctor on 10/21/2015

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