The new research – published in the British Journal of Cancer – was the largest ever of its kind, and included data from various studies across the world, with most people coming from the UK and US.
Some 1.64 million meat eaters were included, alongside 57,016 poultry eaters (no red meat), 42,910 people who ate fish and no meat (pescatarians), 63,147 vegetarians and 8,849 vegans.
It found that vegetarians had a 21% lower risk of pancreatic cancer and a 9% lower risk of breast cancer compared with meat eaters.
They also have a 12% reduced risk of prostate cancer, 28% lower risk of kidney cancer and 31% lower risk of multiple myeloma.
Amy Hirst, health information manager at Cancer Research UK, said the “high-quality study” offered some interesting insights, but the findings were not strong enough to draw definitive conclusions.
She said: “More research in larger, more diverse populations is needed to better understand these patterns and what’s causing them.”
“When it comes to reducing cancer risk, keeping a healthy, balanced diet overall matters more than individual foods,” Hirst added.