Vegetarian diet linked to up to 30% lower risk for five cancers

A pooled analysis in the British Journal of Cancer reports that vegetarians had up to a 30% lower risk of five cancers, while the study also found higher reported risks of the commonest oesophagus cancer in vegetarians and of bowel cancer in vegans, though vegan cases were few.

A pooled analysis published in the British Journal of Cancer examined links between diet type and multiple cancer risks. Researchers combined data from studies mainly in the UK and US and compared meat eaters with poultry eaters, fish eaters, vegetarians and vegans. Participants reported typical food intake over the previous year and analyses accounted for factors such as body mass index. The results raised questions about nutrient differences and prompted calls for more research. Key findings: - Vegetarians were reported to have up to a 30% lower risk of five cancers compared with meat eaters. - Vegetarians were reported as having about twice the risk of the most common type of oesophagus cancer compared with meat eaters. - Vegans had a higher reported risk of bowel cancer compared with meat eaters, but the study included only 93 bowel cancers in the vegan group. - The pooled dataset included more than 1.5 million meat eaters, 57,016 poultry eaters, 42,910 fish eaters, 63,147 vegetarians and 8,849 vegans, with most participants from the UK and US; BMI and recent diet were considered. - Authors and experts noted possible explanations such as higher fruit, vegetable and fibre intake among vegetarians and lower average calcium or other nutrient intakes in some non-meat diets, and they described some results as inconsistent. Summary: The study reports associations between different diet groups and both lower risks for certain cancers and higher risks for others, but it does not establish causation. Researchers and outside experts emphasised that some subgroup analyses involved small numbers and that further research in larger, more diverse populations is needed to clarify which dietary patterns or nutrient differences might explain the observations.