Breast cancer is less likely to return in patients who stick to a low-fat diet, according to a study released on Saturday.
The study, published in the Journal of the National Cancer Institute, involved 2,437 breast cancer survivors, some of whom reduced their daily fat intake by roughly 40 percent while the others stayed about the same as when they started.
The women with the lower-fat diets had a 24 percent lower risk of a recurrence than the other women, according to researchers led by Dr. Rowan Chlebowski of the Los Angeles Biomedical Research Institute in Torrance, California.
"To me, it seems like if women are asking what can they do themselves to prevent a recurrence, then this represents something that they can try," Chlebowski said in a telephone interview.
What role dietary fat plays in a woman's risk of developing breast cancer has been debated by cancer experts.
The American Cancer Society has noted that studies focusing on fat in the diet have not clearly shown this to be a breast cancer risk factor, although being overweight has been found to raise breast cancer risk, especially for women after menopause.
Chlebowski acknowledged that this study will not settle the issue. Women who took part in the study were recruited between 1994 and 2001 and were tracked through 2003. They entered the study with diets averaging about 57 grams (2 ounces) of fat per day, amounting to 30 percent of total calories.
Women in one group decreased their fat intake to 33 grams per day, or 20 percent of total calories, while the other women consumed 51 grams per day, or 29 percent of total calories.
About 9.8 percent of the women on lower-fat diets suffered breast cancer relapses, compared to 12.4 percent of women who did not have lower fat intake.
"A lifestyle intervention reducing dietary fat intake, with modest influence on body weight, may improve relapse-free survival of breast cancer patients receiving conventional cancer management," the researchers wrote.
Chlebowski said the study indicated that women with the faster-growing type of the disease, hormone receptor-negative breast cancer, may experience the largest reduction in relapse risk due to a lower-fat diet. This type of breast cancer is not fed by the hormone estrogen.
The researchers noted that women who ate less fat lost weight, and that the weight loss may have been at least partially responsible for lowering the relapse risk rather than the reduced fat intake alone.