Daijiworld Media Network - London

London, Feb 27: A large international study has found that a vegetarian diet may reduce the risk of five types of cancer, while also highlighting certain potential risks associated with specific plant-based diets.

The research, published in the British Journal of Cancer, is the largest of its kind and analysed data from more than 1.8 million people across three continents through the Cancer Risk in Vegetarians Consortium, led by researchers at the University of Oxford.

The study found that compared with meat eaters, vegetarians had a 21 percent lower risk of pancreatic cancer, 9 percent lower risk of breast cancer, 12 percent lower risk of prostate cancer, 28 percent lower risk of kidney cancer, and 31 percent lower risk of multiple myeloma.

However, vegetarians were found to have a higher risk of squamous cell carcinoma of the oesophagus, an aggressive cancer affecting the flat cells lining the upper and middle parts of the oesophagus.

The research was funded by the World Cancer Research Fund.

For the analysis, researchers compared the risk of 17 different cancers across five dietary groups: 1.64 million meat eaters, 57,016 poultry eaters (who avoided red and processed meat), 42,910 pescatarians (fish eaters), 63,147 vegetarians, and 8,849 vegans.

There were no statistically significant differences for vegetarians in the risk of colorectal, stomach, liver, lung (among never smokers), endometrial, ovarian, mouth and pharynx, bladder cancers, non-Hodgkin lymphoma, leukaemia, or oesophageal adenocarcinoma.

Vegans, however, showed a statistically significant higher risk of colorectal (bowel) cancer compared to meat eaters. For most other cancers, there was no clear evidence that risk among vegans differed from meat eaters, although researchers noted that the number of vegan cases for some less common cancers was too small for detailed analysis.

Pescatarians were found to have lower risks of breast, kidney and bowel cancers, while poultry eaters showed a reduced risk of prostate cancer.

Tim Key, Emeritus Professor of Epidemiology at Oxford Population Health and co-investigator of the study, said cancer remains a leading cause of death globally and that diets rich in fruits, vegetables and fibre, and low in processed meat, are recommended to reduce cancer risk.

Aurora Perez Cornago, principal investigator and formerly Associate Professor at Oxford Population Health, said vegetarians generally consume more fruit, vegetables and fibre and avoid processed meat, which may explain lower risks of some cancers. She added that the higher risk of oesophageal squamous cell carcinoma in vegetarians and bowel cancer in vegans may relate to lower intakes of certain nutrients commonly found in animal-based foods.