Diet and Breast Cancer Risk: Why a New AMA Policy Could Be a Game-Changer

In a move that could reshape the nation’s approach to breast cancer prevention, the American Medical Association has approved a new policy urging healthcare providers to educate patients on the role of diet in lowering breast cancer risk. Passed at the AMA’s 2025 Annual Meeting of the House of Delegates, the resolution directly endorses plant-based eating as part of a prevention-focused strategy.

Breast cancer affects 1 in 8 women in the U.S. during their lifetime. Yet fewer than 3 in 10 know that diet plays a role in prevention.

This significant knowledge gap inspired Physicians Committee for Responsible Medicine President Neal Barnard, M.D., FACC, to draft the AMA’s approved lifestyle-focused prevention education policy. “Every October, during Breast Cancer Awareness Month, people would say, ‘We need more mammography,’” says Barnard, who also serves as an alternate delegate to the AMA for the Medical Society of the District of Columbia. “But the idea of actually having power in your hands to reduce your risk was something that got left out of the equation.”

The focus on prevention represents a notable departure from the traditional approach of public health campaigns around cancer, which have historically prioritized early detection and treatment over risk reduction.

The new AMA policy could shift the national conversation, with its explicit mention of a plant-based diet reflecting the growing evidence of the link between nutrition and cancer outcomes.

Barnard says he expected to meet some resistance when bringing his prevention-focused policy draft to the AMA. “In the past, there was some controversy as to whether or not prevention messages could be confusing or could interfere with detection messaging,” says Barnard. “In other words, if we tell women that ‘Here are things that you can do,’ would that make them less likely to see a doctor to get a mammogram? I was expecting that [feedback].”

Instead, multiple groups and individuals within the AMA expressed strong support for educating patients and the public about lifestyle-focused strategies to reduce breast cancer risk.

The approved policy states: “Our American Medical Association will support efforts to educate the public about the benefits of lifestyle changes that may reduce breast cancer risk, including regular physical activity, maintenance of a healthy body weight, a healthy plant-based diet, and limiting alcohol intake. Our AMA will encourage physicians to regularly discuss with their individual patients the benefits of lifestyle changes that may reduce cancer risk; and be it further.”

Most women are unaware of nutrition’s potential role in breast cancer prevention, according to a 2024 Physicians Committee for Responsible Medicine/Morning Consult survey. Just 28% of the U.S. women surveyed had heard that a healthful diet could lower their risk, with 72% reporting they’d never received such information from a health care professional.

“The result was devastating,” says Barnard. “Women will say, ‘To reduce my risk, I can get a mammogram, or I can do self-examination, or I can see my doctor.’ None of those will reduce your risk.”

Additionally, only 17% were aware that soy products have the potential to lower the likelihood of breast cancer, when there is evidence that eating more soy is linked to a 30% lower risk of developing the disease and a 26% reduced risk of recurrence.

The awareness gap may be even wider in rural communities, where research has shown lower access to preventive care and less nutritious diets. A 2019 policy brief from the Maine Rural Health Research Center found that women living in rural communities are less likely than their urban-based counterparts to receive preventive health care services, including mammograms. And a 2022 study published in September 2022 in the Journal of the Academy of Nutrition and Dietetics found that rural cancer survivors consumed only half as many fruits and vegetables as their urban counterparts, with even lower intake among non-Hispanic Black women.

“Our ultimate goal is not only to conquer the disparities, but to reduce all these numbers to the extent that we can,” says Barnard.

To reach more women across the U.S., PCRM holds a series of rallies tied to its “Let’s Beat Cancer” campaign. These events, which run from September to October (Breast Cancer Awareness Month), promote the same four-pronged approach to prevention outlined in the new AMA policy. Each rally features breast cancer survivors, community members, local leaders, and even area percussionists playing drums to amplify the message that individuals can take charge of their health.

Research shows that family history plays a role in just 10% of cancers, with the remaining 90% associated with lifestyle and environmental factors. The AMA’s new prevention-focused policy focuses on four lifestyle factors. Here’s a brief look at the evidence in each area.

“The call to action is for every doctor to treat diet the way they treat smoking now,” says Barnard. “Years ago, the U.S. Preventive Services Task Force came out and [essentially] said, ‘I don't care if you think your patient won't quit. I don't care if you don't have resources for helping them quit. You must talk to every patient every time about tobacco.’”

The new AMA policy challenges health care professionals to initiate meaningful, ongoing conversations with their patients about the significant role that diet and other lifestyle choices can play in cancer prevention.

Barnard hopes that the updated messaging will have a ripple effect while reducing nationwide rates of breast cancer.

At the end of the day, “Everybody has a voice,” says Barnard. “You never know who you will educate, who you will inspire, who is going to make a change, and who is going to make a meal that makes them think, ‘Going vegan is easier than I thought.’ You're going to save the lives of people you've never even met.”