RELATED VIDEO CNN's Dr. Steve Salvatore reports on low-fat diet study Windows Media 28K 80K

March 10, 1999
Web posted at: 4:10 p.m. EST (2110 GMT)

(CNN) -- Researchers have found no evidence that a low-fat diet helps reduce a woman's risk of breast cancer, according to a new study in the March 10 issue of the Journal of the American Medical Association.

Dr. Michelle Holmes, of Harvard University Medical School and Brigham and Women's Hospital in Boston, led the 14-year study which followed 88,795 women who were cancer-free at the start of the research in 1980.

Researchers looked for a relationship between breast cancer and fat intake by examining the participants' long-term diet through food frequency questionnaires administered in 1980, 1984, 1986 and 1990. The analysis included different types of fat as well as total fat.

"We found no evidence that lower intake of total fat or particular types of fat over 14 years of follow-up was associated with decreased risk of breast cancer," the researchers concluded in the article published in JAMA.

Researchers said previous studies on fat intake and breast cancer risk were inconclusive. The prevailing belief has been that a low-fat diet -- the consumption of less than 20 percent of daily calories from fat -- could reduce a woman's risk of breast cancer.

The study, funded by the National Institutes of Health, was conducted as part of the Brigham and Women's Hospital "Nurses' Health Study."

The research found no increased risk of breast cancer with an increased intake of animal fat, polyunsaturated fat, saturated fat, or trans-unsaturated fat in women who replaced carbohydrates with fat.

The study also showed no evidence of a decrease in the risk of breast cancer with increased intake of vegetable fat or monounsaturated fat. These fats have been found to help prevent heart disease.

While a low-fat diet doesn't appear to change breast cancer risk, researchers did point out that women should be concerned about fat intake in relation to heart disease. Studies do show conclusively that a diet low in fat and cholesterol can reduce the risk of that deadly disease.