Can a Plant-Based Diet Lower Breast Cancer Risk? Study Finds - Video

A recent study published in the European Journal of Clinical Nutrition concludes that following a healthy plant-based diet significantly lowers the risk of breast cancer, particularly in postmenopausal women and those with a healthy weight. Conducted in Iran, the research examined the dietary habits of 133 women diagnosed with breast cancer and 265 healthy women to understand how different plant-based diets impact

cancer risk. Using a detailed food questionnaire, they assessed how closely each woman’s diet matched three plant-based diet indexes:

PDI (Plant-Based Diet Index): Overall intake of plant vs. animal foods

hPDI (Healthful Plant-Based Diet Index): Emphasis on healthy plant foods like fruits, vegetables, legumes, and whole grains

uPDI (Unhealthful Plant-Based Diet Index): Focus on less healthy plant foods like refined grains, sweets, and sugary drinks

Foods were grouped into three categories: animal-based, unhealthy plant-based, and healthy plant-based. Higher scores on each index showed stronger adherence to that diet type.

The findings revealed that women who followed diets rich in whole, unprocessed plant foods—such as fruits, vegetables, whole grains, legumes, nuts, and vegetable oils—had about half the risk of developing breast cancer compared to those who consumed fewer of these foods. In contrast, women consuming plant-based diets high in refined grains, sweets, sugary beverages, and potatoes had a notably higher risk, especially if they were premenopausal.

The study also found that the protective effects of a healthy plant-based diet were strongest in women with a BMI below 25, suggesting that maintaining a healthy weight may enhance the benefits of such diets. These plant-based foods are naturally high in fiber, antioxidants, vitamins, and phytochemicals—compounds known to support DNA protection, regulate cell growth, and reduce inflammation, all of which can contribute to lowering cancer risk.

However, the study had limitations, including unassessed tumor subtypes, potential recall bias from self-reported diets, and a small, hospital-based sample, underscoring the need for larger, broader studies.

Future research should further explore how different types of breast cancer interact with diet and how hormonal status and therapy affect these relationships.

Reference: Souni F, Mansouri F, Jafari F, Sharifi R, PourvatanDoust S, Shateri Z, Nouri M, Rashidkhani B. The association between plant-based diet indices and the risk of breast cancer: a case-control study. J Health Popul Nutr. 2025 Apr 19;44(1):127. doi: 10.1186/s41043-025-00879-2. PMID: 40253371; PMCID: PMC12008985.