New Study: Low-Fat Diet May Reduce Risk of Dying from Breast Cancer

Eating a low-fat diet rich in fruits, vegetables, and whole grains may significantly increase a woman’s chance of breast cancer survival, according to a new study that will be presented at the American Society of Clinical Oncology meeting next month. The researchers analyzed data from a randomized, controlled clinical trial that included nearly 49,000 postmenopausal women—some of whom followed a low-fat, plant-packed diet for eight years while the rest made no dietary changes. None of the participants had a prior history of breast cancer.

Although most women in the low-fat diet group did not meet their goal of getting just 20 percent of their daily calories from fat, nearly all managed 25 percent, compared with the control group’s more typical American diet of 32 percent and up. The findings so far, two decades after the trial began: Women in the low-fat diet group had a 21 percent lower risk of dying from breast cancer than those in the control group. What’s more, women in the low-fat diet group had a 15 percent lower risk of dying from any cause after a breast cancer diagnosis. (There was also an average 3 percent weight loss for women in the low-fat diet group.)

“Ours is the first randomized, controlled trial to prove that a healthy diet can reduce the risk of death from breast cancer,” says lead study author Rowan Chlebowski, MD, PhD, FASCO, from the Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center in Torrance, California. “The balanced diet we designed is one of moderation, and after nearly 20 years of follow-up, the health benefits are still accruing.”

“I have worked nearly three decades on this issue. It is satisfying to know that a dietary moderation approach, easily achievable by many—over 19,000 postmenopausal women were in the intervention group—can result in a statistically significant reduction in deaths from breast cancer, a major concern of postmenopausal women,” Chlebowski says.

While it’s impossible to say which variable—lower intake of fat, higher intake of fiber and nutrients from plant foods, or a combination of both—should take credit for the outcome, the results support prior research and a 2018 report from the World Cancer Research Fund and the American Institute for Cancer Research, which recommends eating less red and processed meat and more fruits, vegetables, whole grains, and legumes to protect against cancer.

Ready to get started? Check out Forks Meal Planner, FOK’s easy weekly meal-planning tool to keep you on a healthy plant-based path.