UK: A study of 1.8 million individuals, published in the British Journal of Cancer, has found that vegetarians had a lower risk of multiple myeloma and kidney, pancreatic, prostate, and breast cancers compared with meat eaters. However, vegans showed a higher rate of colorectal cancer, possibly linked to lower calcium intake, though further research with larger vegan populations is needed to confirm this finding.
The large pooled analysis was led by Yashvee Dunneram from the Cancer Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, and colleagues. The consortium brought together data from nine prospective cohort studies conducted across the UK, the United States, Taiwan, and India, making it one of the most comprehensive evaluations of vegetarian dietary patterns and cancer risk to date.
The analysis included 1,645,555 meat eaters, 57,016 poultry eaters, 42,910 pescatarians, 63,147 vegetarians, and 8,849 vegans. Participants were followed for a median of 16 years, during which investigators documented incident cases of multiple cancer types, including colorectal, breast, prostate, pancreatic, kidney, lung (in never smokers), and several hematological malignancies. Multivariable Cox regression models were applied within each cohort, and results were combined using meta-analytic techniques.
The following were the key findings:
Poultry eaters had a modestly lower risk of prostate cancer compared with meat eaters.
Pescatarians showed reduced risks of colorectal, breast, and kidney cancers.
Vegetarians had lower risks of pancreatic, breast, prostate, and kidney cancers, as well as multiple myeloma.
Vegetarians, however, had a higher risk of squamous cell carcinoma of the oesophagus.
Vegans demonstrated a significantly higher risk of colorectal cancer compared with meat eaters.
The increased colorectal cancer risk observed among vegans may be linked to differences in nutrient intake, such as lower calcium consumption. However, the small number of cases in this group limits definitive conclusions.
The researchers emphasized that while the dataset represents the majority of prospective evidence worldwide on vegetarian diets and cancer outcomes, several limitations must be acknowledged. Some moderately sized cohorts with fewer vegetarians were not included, and there is a possibility of minor participant overlap between certain UK and US studies. Additionally, given the number of statistical comparisons performed, some findings could reflect chance associations. The authors interpreted all results cautiously.
They also highlighted that dietary patterns can vary substantially across and within countries, meaning the generalizability of the findings may be limited, particularly outside Western Europe and North America, where most participants resided.
Overall, the findings suggest that different forms of vegetarian diets may be associated with varying risks for specific cancers. The authors called for further research to explore potential biological pathways, including metabolic factors and nutrient deficiencies, and to gather more data in vegan populations and non-Western settings to clarify these associations.
Reference:
Dunneram, Y., Lee, J. Y., Watling, C. Z., Lawson, I., Parsaeian, M., Fraser, G. E., Butler, F. M., Prabhakaran, D., Shridhar, K., Kondal, D., Mohan, V., Ali, M. K., Narayan, K. M., Tandon, N., Tong, T. Y., Travis, R. C., Chiu, T. H., Lin, M. N., Lin, C. L., . . . Perez-Cornago, A. (2026). Vegetarian diets and cancer risk: Pooled analysis of 1.8 million women and men in nine prospective studies on three continents. British Journal of Cancer, 1-12. https://doi.org/10.1038/s41416-025-03327-4
