A low-fat diet may decrease the risk of ovarian cancer in postmenopausal women, according to a study published online Oct. 9 in the Journal of the National Cancer Institute.
The Women's Health Initiative Dietary Modification Randomized Controlled Trial previously demonstrated that a low-fat diet may reduce the risk of breast and colorectal cancer in postmenopausal women, but it was not yet known whether the same diet would alter ovarian-cancer risk.
Dr. Ross Prentice of the Center's Public Health Sciences Division and colleagues analyzed data from the diet-modification trial to see if the changes in the women's diets also decreased the risk of ovarian and endometrial cancer and invasive cancers overall.
In the trial, nearly 20,000 women received random assignment to the diet-modification group and almost 30,000 women ate their normal diet. The women participating in the modified diet were asked to reduce their fat intake to 20 percent of their overall diet, as well as eat at least five serving of fruits and vegetables a day and at least six servings of whole grains. Researchers followed the group for an average of eight years.
The risk of ovarian cancer was similar in the two groups for the first four years of follow-up, but it was reduced in the dieting group during the subsequent years. Women who had the highest fat intake before the trial saw the greatest reduction in risk. There was no difference in endometrial-cancer risk between the two groups, but a reduction in invasive cancers overall was suggested in the dieting group.
"Follow-up of trial participants may provide additional valuable assessment of the effects of a low-fat dietary pattern on these and other cancer incidence rates," the authors write.
[Adapted from a Journal of the National Cancer Institute news release.]