Low-fat diet leads to positive outcomes for cancer, other disease, in women

There may be several women’s health benefits from a low-fat diet, according to a new study by researchers at the Fred Hutchinson Cancer Research Center in Seattle, Washington, and published in the Journal of Nutrition.

The study, launched as the Dietary Modification Trial in 1993 and funded by the National Heart, Lung, and Blood Institute, involved nearly 49,000 postmenopausal women across the U.S. to test whether a low-fat dietary pattern commensurate with an increase in fruit, vegetable, and grain servings would reduce the risk of breast and colorectal cancers and coronary heart disease.

After nine years of dietary change, they found that the low-fat diet did not significantly impact outcomes for these conditions. However, after longer-term follow-up of nearly 20 years, researchers found several benefits, including a 15 to 35 percent reduction in deaths from all-causes following breast cancer, a 13 to 25 percent reduction in insulin-dependent diabetes, and a 15-30 percent reduction in coronary heart disease among 23,000 women without baseline hypertension or prior cardiovascular disease.

Unlike other studies examining the link between diet, cancer, and other diseases, investigators designed this study as a long-term, randomized controlled clinical trial to limit bias and establish causal conclusions. Participants made intentional dietary changes resulting from learned integrated concepts about nutrition and behavior, taught by trained nutritionists during the first year and reinforced quarterly for nearly a decade. according to Ross Prentice, PhD, member of the Cancer Prevention and Biostatistics programs at the Fred Hutchinson Cancer Research Center, and lead author of the study.

"The [study] has provided women with nutrition and disease prevention insights for some years," said Prentice. "The latest results support the role of nutrition in overall health, and indicate that low-fat diets rich in fruits, vegetables, and grains have health benefits without any observed adverse effects."