A very large European analysis suggests that the quality of plant foods—not strict veganism—may matter for breast cancer prevention. Researchers pooled data from 258,343 women in the EPIC cohort and tracked them for a median 14.9 years, identifying 10,805 invasive breast cancer cases.
The team scored diets three ways: an overall plant‑based diet index (PDI); a healthful PDI (hPDI) emphasizing whole grains, fruits, vegetables, legumes, nuts, vegetable oils, and coffee/tea; and an unhealthful PDI (uPDI) that weights refined grains, potatoes, sweets, sugar‑sweetened drinks, and fruit juice more heavily. Animal foods (meat, fish, eggs, dairy, animal fats) were scored inversely.
What they found: Each step toward a more healthful plant‑forward pattern was associated with a modestly lower breast cancer risk—about 3% lower risk per standard‑deviation increase in the hPDI score (hazard ratio 0.97; 95% CI 0.94–0.99). In contrast, the overall plant‑based index was borderline (HR 0.98; 0.96–1.00) and the unhealthful plant‑based score showed no benefit (HR 1.01; 0.99–1.03).
In postmenopausal women, part of the association between a healthier plant‑based diet and lower breast cancer risk appeared to be explained by body size: about 30% of the link ran through BMI and about 52% through waist circumference in formal mediation analyses—suggesting weight and central adiposity are important pathways. (See Figure 2 in the paper.) The pattern of results looked similar across tumor subtypes (ER/PR/HER2) in the study’s forest plot (Figure 1).
Why it matters for readers:
- This is among the largest prospective looks at plant‑based eating and breast cancer in Europe, lending statistical power and long follow‑up.
- It reinforces a practical message: not all plant‑based diets are equal. Diets richer in minimally processed plant foods were linked to lower risk; plant‑based diets dominated by refined carbs and sugary drinks were not.
- Keeping a healthy weight and waist likely contributes to the benefit.
Take‑home tips (The Nano Post): Build plates around vegetables, fruit, beans, lentils, whole grains, nuts, and olive/other vegetable oils, and cut back on sweets, refined grains, sugary beverages, and fries. You don’t have to eliminate animal foods to move your score in the right direction—simply shifting the balance toward higher‑quality plant foods helps.
Caveats: This was an observational study, so it can’t prove cause and effect; diets were self‑reported once at baseline; and results come from European populations, which may limit generalizability. Still, sensitivity checks supported the main findings, and the overall message aligns with broader evidence on diet, weight, and cancer. (Published online July 14, 2025, European Journal of Epidemiology.)
Source: Shah S. et al., “Plant‑based dietary patterns and breast cancer risk in the EPIC study.”
Editor’s note: This article is for information only and is not a substitute for professional medical advice.