Women who regularly eat a low-fat, plant-based diet can lower their risk for breast cancer death significantly, a new study says.
Researchers from the Harbor-UCLA Medical Center examined data from more than 48,000 women who were part of a long-term program launched by the Women's Health Initiative in 1993.
The participants were in their 50s, 60s, and 70s, and were already postmenopausal. They have never been diagnosed with breast cancer before.
Nearly half of the women were asked to keep a log of their diet over the next eight years. They were told to eat less dietary fat, such as full-fat dairy products and red meat, and consume more produce, such as whole grains, fruits, and vegetables.
After monitoring the development of the participants for 20 years, the research team found that participants who were able to follow the suggested diet lowered their risk for breast cancer death by as much as 20 percent.
Dr. Rowan Chlebowski, a researcher from Harbor-UCLA's Los Angeles Biomedical Research Institute and lead investigator of the study, pointed out that it was the first randomized trial to feature breast cancer as an endpoint. He said their work was able to show a reduction in deaths caused by the illness.
Dietary Change Is The Key
The researchers believe the change in the women's diet is the key to the positive outcome they have observed.
The dietary intervention was meant to reduce the participants' fat intake to 20 percent of their daily calories from fat while also increasing their consumption of whole grains, fruits, and vegetables.
Not all of them were able to meet this goal, but it did not seem to matter. The women experienced benefits from the new diet even if they were only able to cut fat intake by 24.5 percent. The eating plan also allowed them to lose 3 percent of their body weight.
While the research team found a lowering of death rates related to breast cancer, it did not observe any reduction in breast cancer rates overall. It is still unclear why this was the case.
Some health experts believe it may be too early to tell whether a low-fat, plant-based diet does not protect women from breast cancer.
"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," explained Dr. Neil Iyengar, an expert on the relationship between diet and cancer at the Memorial Sloan Kettering Cancer Center.
"Diet is a powerful tool in changing the way cancer behaves or responds to treatment."
Switching Up Food Preparation And Portions
The study participants followed the dietary intervention by staying in their food comfort zone.
Chlebowski explained that this can be done largely with substitutions. People do not necessarily have to change what they eat, but they can change their food preparation and choose smaller portions.
For example, reducing the portion of meat on the plate would not only cut out dietary fat, but it would also allow more room for healthier options such as grains and vegetables.
The findings of the LA Biomedical Research Institute study will be presented at the upcoming conference of the American Society of Clinical Oncology in June.