For years, they have boasted of the health benefits of their leafy diets, but now vegetarians have the proof that has so far eluded them: When it comes to cancer risks, they have the edge on carnivores.
Fresh evidence from the largest study to date to investigate dietary habits and cancer has concluded that vegetarians are 45 percent less likely to develop cancer of the blood than meat eaters and are 12 percent less likely to develop cancer overall.
Scientists said that while links between stomach cancer and eating meat had already been reported, they had uncovered a “striking difference” in the risk of blood cancers including leukemia, multiple myeloma and non-Hodgkin’s lymphoma between the groups. The study looked at vegetarians, fish eaters and people who ate meat.
Co-author Naomi Allen, from the Cancer Research UK epidemiology unit at Oxford University, said: “Previous research has found that processed meat may increase the risk of stomach cancer, so our findings that vegetarians and fish eaters are at lower risk is plausible. But we do not know why cancer of the blood is lower in vegetarians.”
However, Allen urged caution when interpreting the findings.
“It is a significant difference, but we should be a bit cautious since it is the first study showing that the risk of cancer of the blood is lower in vegetarians,” she said. “We need to know what aspect of a fish and vegetarian diet is protecting against cancer. Is it the higher fiber intake, higher intake of fruit and vegetables, is it just meat per se?”
The study also reported that the total cancer incidence was significantly lower among both the fish eaters and the vegetarians compared with meat eaters.
The study, published in the British Journal of Cancer, is part of a long-term international study, the European prospective investigation into cancer and nutrition.
The findings were based on a study of 61,000 people who scientists followed over 12 years. During this time, 3,350 participants were diagnosed with cancer. Of those, 68 percent (2,204) were meat eaters, 24 percent (800) were vegetarians and 9.5 percent (300) ate fish but no meat.
They found that 180 meat eaters developed blood cancers, while 49 vegetarians developed the diseases and 28 fish eaters.
They found the risk of being diagnosed with cancers of the stomach, bladder and blood was significantly lower in vegetarians than in meat eaters but, in contrast to earlier work, they found the rate of bowel cancer was slightly higher among vegetarians than meat eaters.
A spokesman for BPEX, the British pig executive, questioned the methodology of the study: “We are unable to take a view on this because there is mixed evidence based on the compounding factors to do with lifestyle that come into it.”