Vegetarianism equals lower cancer risk but new study finds exceptions

A massive study tracking nearly 1.8 million people has found vegetarians face a lower risk of several major cancers — but the research also uncovered unexpected increases in others, complicating the idea that plant-based diets are a simple shield against the disease.

Published in the British Journal of Cancer, the long-term study followed participants for around 16 years, comparing cancer diagnoses across different diets including meat-eaters, pescatarians, vegetarians and vegans.

The results suggest plant-heavy diets may offer meaningful protection against some cancers — but not all.

Lower risk for several major cancers

Researchers found people following vegetarian diets had significantly lower rates of several serious cancers.

The risk of Pancreatic Cancer was 21% lower among vegetarians compared with meat-eaters. Rates of Breast Cancer dropped by 9%, while Kidney Cancer and Multiple Myeloma — a rare blood cancer — fell by 28% and 31% respectively.

Experts say plant-rich diets tend to be high in fibre, vitamins and anti-inflammatory compounds that support gut health and help maintain a healthy body weight — both key factors in cancer prevention.

However, researchers stress that diet is only one piece of a much larger puzzle that includes smoking, alcohol use, exercise levels and environmental exposure.

Unexpected risks raise new questions

The same data also revealed troubling exceptions.

Vegetarians were found to have nearly double the risk of Esophageal Cancer, while vegans showed about a 40% higher risk of Colorectal Cancer compared with meat-eaters.

Scientists caution the study shows correlation rather than cause, but several theories have emerged. Strict plant-based diets can sometimes lead to lower levels of key nutrients such as B vitamins, calcium and certain minerals — all potentially important for cancer protection.

Another factor may be the rise of ultra-processed meat substitutes in modern vegan diets.

Researchers say the clearest takeaway is not necessarily to eliminate meat entirely. Instead, evidence consistently points to a balanced diet rich in whole plant foods — vegetables, fruit, legumes, nuts and whole grains — alongside healthy lifestyle habits as the most reliable strategy for lowering cancer risk.

Study of 1.8m people links vegetarianism to lower risk of several cancers – here's the takeaway