NEW DELHI: A vegetarian diet can reduce the risk of five types of cancer, a new study published Friday said.
The new research, the largest ever of its kind, found that vegetarians have lower risks of several cancers - pancreatic, breast, kidney and prostate cancer, as well as multiple myeloma - when compared to meat eaters.
However, it said that vegetarians are at a higher risk of squamous cell carcinoma of the oesophagus, a common, aggressive cancer arising from the flat, thin cells lining the upper/middle oesophagus.
The study, published in the British Journal of Cancer, also suggested that people should eat wholegrains, pulses, fruit and vegetables, and avoid processed meat and limit red meat.
For the study, the researchers from the University of Oxford surveyed more than 1.8 million people from three continents through the Cancer Risk in Vegetarians Consortium.
They compared the risk of 17 different cancers across five diet groups: meat eaters, poultry eaters (do not eat red or processed meat), pescatarians (fish eaters), vegetarians (eat dairy and/or eggs), and vegans.
For the study, 1.64 million meat eaters, alongwith 57,016 poultry eaters (no red meat), 42,910 people who ate fish and no meat (pescatarians), 63,147 vegetarians and 8,849 vegans were surveyed.
The study, funded by the World Cancer Research Fund, found that compared with meat eaters, vegetarians had 21% lower risk of pancreatic cancer; 9% lower risk of breast cancer; 12% lower risk of prostate cancer; 28% lower risk of kidney cancer; and 31% lower risk of multiple myeloma.
There were no statistically significant differences in risk for colorectal, stomach, liver, lung (in never smokers), endometrial, ovarian, mouth and pharynx, or bladder cancers, or non-Hodgkin lymphoma, leukaemia, and oesophageal adenocarcinoma in vegetarians.
Tim Key, Emeritus Professor of Epidemiology at Oxford Population Health, and co-investigator of the study, said, “Cancer is a leading cause of death worldwide, accounting for nearly one in six deaths. Dietary patterns that prioritise fruit, vegetables, and fibre-containing foods, and avoid processed meat, are recommended to reduce cancer risk. Our study helps to shed light on the benefits and risks associated with vegetarian diets.”
Vegans had a statistically significant higher risk of colorectal (bowel) cancer when compared with meat eaters.
For the other cancers studied, there was no evidence that risk in vegans differed from that of meat eaters, and for some less common cancers, there were too few vegan cases to analyse, the study said.
Pescatarians had lower risks of breast and kidney cancers, as well as a lower risk of bowel cancer. Poultry eaters were found to have a lower risk of prostate cancer.
Aurora Perez Cornago, principal investigator of the study and formerly Associate Professor at Oxford Population Health, added, “Vegetarians typically consume more fruit, vegetables and fibre than meat eaters and no processed meat, which may contribute to lower risks of some cancers. The higher risk of oesophageal squamous cell carcinoma in vegetarians and bowel cancer in vegans may relate to lower intakes of certain nutrients more abundant in animal foods.”