Daijiworld Media Network - London

London, Feb 27: Vegetarians have a substantially lower risk of developing five types of cancer, according to a landmark study examining the long-term impact of diet on cancer incidence.

The research, published in the British Journal of Cancer, analysed data from over 1.8 million people tracked for an average of 16 years. It found that vegetarians had a 21% lower risk of pancreatic cancer, a 12% lower risk of prostate cancer, and a 9% lower risk of breast cancer compared with meat eaters. Together, these cancers account for around a fifth of cancer-related deaths in the UK.

The study also reported a 28% lower risk of kidney cancer and a 31% lower risk of multiple myeloma among vegetarians.

Dr Aurora Pérez-Cornago, the principal investigator who conducted the research while based at the University of Oxford, described the findings as encouraging. “This study is really good news for those who follow a vegetarian diet because they have a lower risk of five cancer types, some of which are very prevalent in the population,” she said.

However, the study also highlighted potential risks. Vegetarians were found to have nearly double the risk of oesophageal squamous cell carcinoma—the most common form of oesophageal cancer—compared with meat eaters. Researchers suggested this could be linked to deficiencies in key nutrients such as B vitamins.

Vegans, meanwhile, showed a 40% higher risk of bowel cancer compared with meat eaters. The researchers pointed to lower average calcium intake—around 590 mg per day, below the UK recommendation of 700 mg—as well as reduced intake of other nutrients, as possible contributing factors.

The study was funded by the World Cancer Research Fund and examined 17 different cancer types, including cancers of the gastrointestinal tract, lungs, reproductive system, urinary tract, and blood.

Researchers compiled data from multiple international diet and health studies, allowing them to assess cancer risks among approximately 1.64 million meat eaters, 57,016 poultry eaters, 42,910 pescatarians, 63,147 vegetarians, and 8,849 vegans. Adjustments were made for factors such as body mass index and smoking.

Prof Tim Key, emeritus professor of epidemiology at the University of Oxford and co-investigator, said more research is needed to determine whether the reduced cancer risk is due to avoiding meat or to specific protective elements in vegetarian diets. “My feeling is the difference is more likely to be due to the meat itself, but that’s an opinion that we haven’t looked at directly,” he noted.

The study found no evidence that vegetarians had a lower risk of bowel cancer compared with meat eaters, which researchers attributed to relatively low red and processed meat consumption among participants in the analysed cohorts. The findings, Key said, are “not incompatible” with earlier research linking red and processed meat to bowel cancer risk.

Scientists emphasised that further investigation is required to clarify the mechanisms behind the associations and to better understand how dietary patterns influence different cancer types.