A major international analysis – the largest of its kind – has found that people who follow vegetarian diets are significantly less likely to develop several common cancers compared with regular meat eaters. The research combined data on nearly 1.8 million adults from studies across the UK, US and other countries to assess how diet relates to cancer risk.
Lower cancer risks for vegetarians:
Compared with people who eat meat, vegetarians had reduced risks for several cancers:
Pancreatic cancer: ~21 % lower
Breast cancer: ~9 % lower
Prostate cancer: ~12 % lower
Kidney cancer: ~28 % lower
Multiple myeloma (a blood cancer): ~31 % lower
These five cancers together account for tens of thousands of deaths and new diagnoses each year.
Not all results were positive:
Vegetarians were found to have almost double the risk of oesophageal squamous cell carcinoma compared with meat eaters, and vegans showed a higher risk of bowel cancer – possibly linked to lower intakes of nutrients like calcium and vitamin B12 that are more abundant in animal foods.
Poultry-only diets:
Those who ate only poultry and no red meat had slightly lower cancer risks than people who ate all types of meat – suggesting that reducing red and processed meat intake may be beneficial, even if someone doesn’t adopt a fully vegetarian diet.
Scientists behind the research say the results point to dietary patterns – not just celebrity trends – influencing cancer risk. Lower consumption of processed and red meats combined with higher intakes of whole grains, pulses, fruits and vegetables appears to be protective.
Processed meats (like bacon, salami and ham) are already known to be linked with increased cancer risk, particularly bowel cancer. This may be due to compounds formed during processing or cooking that can damage DNA.
This new study adds to a growing body of research suggesting plant-based and low-meat diets can be associated with lower risks for various cancers:
Other large observational studies have found that vegetarian or vegan diets are linked with generally lower cancer rates overall – though results vary depending on population and methods used.
Some research, such as the Adventist Health Study-2, reported that vegetarians had a lower risk of several site-specific cancers (e.g., colorectal, stomach, breast and prostate), and vegans sometimes showed even stronger associations.
However, scientists urge caution: these are observational studies and can show associations but not prove direct cause and effect. Lifestyle factors like body weight, physical activity and smoking habits – which often differ between diet groups – may also play a role.
A large pooled analysis finds that vegetarians are significantly less likely to develop several major cancers compared with meat eaters, reinforcing advice to eat more plant-based foods.
Some cancer risks – especially for rarer cancers – may be higher in strict vegetarian or vegan diets, possibly due to nutrient shortfalls.
Overall, the evidence supports limiting processed and red meat and building meals around whole plant foods as part of a balanced, cancer-aware eating pattern.