A landmark study has found that vegetarians have a substantially lower risk of five types of cancer, but nearly double the risk of the most common form of oesophageal cancer compared with meat eaters. The research, published in the British Journal of Cancer, analysed data from over 1.8 million people across the world who were tracked for an average of 16 years.
Vegetarians had a 21% lower risk of pancreatic cancer, 12% lower risk of prostate cancer, 9% lower risk of breast cancer, 28% lower risk of kidney cancer, and 31% lower risk of multiple myeloma. These cancers account for about a fifth of UK cancer deaths.
However, vegetarians had nearly double the risk of squamous cell carcinoma of the oesophagus. Researchers suggested this may be due to deficiencies in key nutrients such as B vitamins. Vegans had a 40% higher risk of bowel cancer, possibly linked to low calcium intake (average 590mg/day versus the UK recommendation of 700mg/day).
The study involved 1.64 million meat eaters, 57,016 poultry eaters, 42,910 pescatarians, 63,147 vegetarians, and 8,849 vegans. Factors like BMI and smoking were accounted for. No evidence was found for a lower bowel cancer risk among vegetarians, likely because meat intake was relatively low in the study group.
Dr Aurora Pérez-Cornago, lead investigator from the University of Oxford, said the findings were good news for vegetarians but noted more research is needed. Professor Tim Key, co-investigator, suggested the protective effect may be due to avoiding meat rather than something specific in vegetarian diets.
