LONDON - Vegetarians are less likely than meat eaters to develop some cancers, a major study has found.

The study involving 61,566 people found that vegetarians developed fewer cancers of the blood, bladder and stomach but their diet did not seem to protect bowel cancer.

During the research conducted over 12 years, 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.

The study by researchers from universities in Britain and New Zealand, published in the British Journal of Cancer, followed meat-eaters, those who ate fish but not meat, and those who ate neither meat nor fish.

Fish eaters actually had the lowest rate of cancer - 18 percent lower than meat eaters - but they were also the smallest sample.

According to a 2006 State of the Nation survey by The Hindu-CNN-IBN, 31 percent of Indians are vegetarians. Women and people above the age of 55 are more likely to be vegetarian, the survey found. But it did not disaggregate the figures according to those who eat fish but no meat.

The cancer study published Wednesday suggested that while in the general population about 33 people in 100 will develop cancer during their lifetime, for those who do not eat meat that risk is reduced to about 29 in 100.

The study found 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.

In the case of multiple myeloma, a cancer of the bone marrow, vegetarians were 75 percent less likely to develop the disease than meat-eaters.

Co-author Naomi Allen, from the 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.”

Although the numbers of cases were small, fish-eaters and vegetarians were about a third as likely to develop stomach cancer as meat-eaters.

Professor Tim Key, the lead author, said it was impossible to draw strong conclusions from this one single study.

“At the moment these findings are not strong enough to ask for particularly large changes in the diets of people following an average balanced diet.”

A spokesperson for Cancer Research UK, which funded the research, said: “We know that eating a lot of red and processed meat increases the risk of stomach cancer.

“But the links between diet and cancer risk are complex and more research is needed to see how big a part diet plays and which specific dietary factors are most important.

In 2005, a European study concluded that eating just two portions of red meat a day - the equivalent of a bacon sandwich and a fillet steak - increased the risk of bowel cancer by 35 percent.

It found that eating fibre in the form of vegetables, fruit and wholegrain cereals, lessened the risk of cancer and that fish, eaten at least every other day, was also protective.