Plant-based diet may cut breast cancer risk

March 5, 2010 in Cancer Prevention, Nutrition Topics in the News, Women's Health

Plant-based diet may cut breast cancer risk

Diets high in vegetables, fruits and soy might cut the risk of developing breast cancer by 30 percent, new research from Colorado State University suggests.

In the study, researchers noticed a trend of "decreasing breast cancer risk with increasing intake of a vegetable-fruit-soy dietary pattern" in the 34,000 Chinese women studied.

Even though the researchers identified and analyzed dietary patterns among Chinese women from Singapore, they believe the findings are relevant for North American women.

For the study, reported in the American Journal of Clinical Nutrition, the investigators analyzed data collected between 1993 and 1995 from 63,257 men and women in the Singapore Chinese Health Study (SCHS). The large health study used in-person interviews to gather information about diet, weight, education, smoking and exercise habits, and hormone use.

The data identified two dietary patterns: the meat-starch-saturated-fat based "meat-dim sum" pattern and the "vegetable-fruit-soy" pattern characterized by plenty of cruciferous vegetables such as broccoli, cauliflower, Brussels sprouts, kale, cabbage, and bok choy. (Previous studies have suggested that a high intake of these vegetables may guard against breast cancer. Phytochemicals in cruceriferous vegetables are thought to protect from cancer by regulating detoxification enzymes in the liver.)

Based on their self-reported intake of 165 foods, participants were assigned a score for the vegetable-fruit-soy and the meat-dim sum dietary patterns.

The research group identified 34,028 women with no history of breast cancer in the data. All women were between the ages of 45 and 74. For the most part, they were thin, they exercised, had gone through menopause, and few smoked or used hormone replacement therapy.

By the end of 2005, 10 years after the enrolment interviews, 629 breast cancer cases had been identified among study participants. The greater the intake of vegetables, fruits and soy, the lower the breast cancer risk among post-menopausal women.

The researchers did not find an association between higher meat-dim sum consumption and increased breast cancer risk. The researchers cautioned, however, that North Americans shouldn't read too much into this finding because the discrepancy could be explained by the way meat is prepared.

Stir-fried meats don't contain as many carcinogenic heterocyclic amines (HCAs) that result from cooking muscle meats at high temperatures. Researchers have identified 17 HCAs that may be associated with increased cancer risk. The charred barbeque meat that North Americans often consume contains a higher load of HCAs.

Eating a diverse diet that can be characterized as having plenty of fruits and vegetables and soy appears to guard against breast cancer.

Leslie's tips:

  • Include at least 7 servings of fruit and vegetables (combined) in your daily diet. (One serving is equivalent to a medium sized fruit, 1/4 cup dried fruit, 1/2 cup of 100% juice, 1/2 cup of cooked or raw vegetables and 1 cup of salad greens.)
  • Include a serving of cruciferous vegetables in your diet 3 to 5 times per week.
  • Consider adding soy foods to your diet such as soybeans, tofu and soy beverages.

All research on this web site is the property of Leslie Beck Nutrition Consulting Inc. and is protected by copyright. Keep in mind that research on these matters continues daily and is subject to change. The information presented is not intended as a substitute for medical treatment. It is intended to provide ongoing support of your healthy lifestyle practices.