Photo: Ivar Leidus via Wikimedia Commons, CC BY-SA 4.0, cropped. This adapted image is also licensed CC BY-SA 4.0.
Vegan diets are linked to a 23% lower risk of cancer overall compared with non-vegetarian diets, according to a systematic review and meta-analysis published in the European Journal of Epidemiology on March 25.
Led by Dagfinn Aune at Imperial College London, the team pooled 17 publications from seven prospective studies. Vegetarians had a 13% lower overall cancer risk, plus lower risks of stomach (45%), pancreatic (23%), colorectal (14%), bladder (22%) and breast (8%) cancer, melanoma and non-Hodgkin lymphoma. Vegans also had a 20% lower risk of breast cancer.
Using World Cancer Research Fund criteria, the authors judged the evidence linking vegetarian diets to lower total, colorectal and breast cancer risk as "probable", the second-highest grade, according to the paper summarises. Lower body weight explained part of the benefit.
The authors conclude: "Vegetarian diets compared to non-vegetarian diets are associated with reduced risk of total cancer and seven specific cancer types, while vegan diets are associated with reduced risk of total and breast cancer."
They add that the results support recommendations to adopt much more plant-based diets for cancer prevention.
It comes just weeks after an Oxford study of 1.8 million people linked vegetarian diets to a lower risk of five cancers, and years after scientists found blood from vegans is eight times more protective against cancer.
The evidence keeps stacking up.