Eating a low-fat, plant-based diet could help significantly lower a woman's risk of dying from breast cancer, and the key appears to be changing eating habits before tumors have a chance to develop, according to a study released Wednesday, May 15, NBC News reports.
The new findings are from a long-term analysis of the federally funded Women's Health Initiative, and included data on more than 48,000 postmenopausal women across the U.S.When the WHI study began in 1993, the women were in their 50s, 60s and 70s, and had never been diagnosed with breast cancer.
Nearly 20,000 of those women spent the next eight years carefully logging what they ate, aiming for less dietary fat, such as red meat and full-fat dairy products, and more fruit, vegetables and whole grains.
The women were tracked for 20 years, through 2013. Researchers from the Los Angeles Biomedical Research Institute at the Harbor-UCLA Medical Center who analyzed the data found that women who stuck to the low-fat, plant-based diet had a 20 percent lower risk of dying from breast cancer.
"This is the first randomized trial where breast cancer was an endpoint, and we've been able to show a reduction in deaths," said study author Dr. Rowan Chlebowski of the Los Angeles Biomedical Research Institute.
Breast cancer is the second deadliest cancer among women, according to the American Cancer Society.
The new study did not find a significant drop in breast cancer cases overall, although it's unclear why. It's too soon to say that a low-fat, plant-based diet does not protect a women from developing breast cancer, experts note.
"It could be that we need more follow-up, or that the effect on cases would have been stronger if the diet was continued for a longer period of time," said Dr. Neil Iyengar, who studies the relationship between diet and cancer at Memorial Sloan Kettering Cancer Center. He was not involved in the new research.
One thing is certain, Iyengar said. "Diet is a powerful tool in changing the way cancer behaves or responds to treatment."
Other cancer experts agree. "That healthy start is going to make a difference going through treatment," said Dr. Chasse Bailey-Dorton, chief of integrative oncology at the Levine Cancer Institute in Charlotte, North Carolina.
"We don’t know why so many of us get breast cancer," Bailey-Dorton said. "There are multiple factors. But the more factors you can take out, you're going to have a different outcome."
The findings are scheduled to be presented at the annual conference of the American Society of Clinical Oncology in June.