Overview
- An Oxford-led pooled analysis of more than 1.8 million participants across nine long-term cohorts tracked 17 cancer types over about 16 years and was published in the British Journal of Cancer with funding from the World Cancer Research Fund.
- Compared with meat-eaters, vegetarians showed lower risks for five cancers: pancreatic (~21%), breast (~9%), prostate (~12%), kidney (~28%), and multiple myeloma (~31%).
- The study also reported higher risks for some outcomes, including about double the risk of esophageal squamous cell carcinoma among vegetarians and an estimated 40% higher colorectal cancer risk in vegans based on 93 cases, which the authors advise interpreting cautiously.
- Researchers hypothesize that nutrient differences, such as lower intakes of calcium, B‑vitamins, zinc or riboflavin in some plant-based patterns, may contribute to the elevated risks, though mechanisms remain unproven.
- Additional patterns were observed for non-vegetarian plant-forward diets, with pescetarians showing lower risks for bowel, breast and kidney cancers and poultry-eaters showing lower prostate cancer risk compared with red-meat consumers, while experts stress the findings do not prove causation and call for broader, more diverse studies.