Eating a vegetarian diet can almost halve the risk of developing cancer, research suggests.

A study of more than 61,000 individuals aged between 20 and 89 found those who did not eat meat reduced overall incidence of the disease by 12 per cent.

But the most striking difference was in cancers of the blood, including leukaemia and non-Hodgkin lymphoma with 45 per cent fewer cases among the vegetarians.

Research suggests there are 45 per cent fewer cases of leukaemia and non-Hodgkin lymphoma among vegetarians

Tumours of the stomach and bladder were also significantly less frequent in this group.

Professor Tim Key, a Cancer Research UK epidemiologist at the University of Oxford, said: 'Over a lifetime about one in three people will be diagnosed with cancer. So if 33 people in every hundred get cancer this would come down to about 29 with everyone following a vegetarian diet, which is 12 per cent lower.'

However, Mr Key said the findings were not yet strong enough to advise the public to make dramatic changes to the way they eat as long as they are following an 'average balanced diet'.

Although it is widely recommended we eat five portions of fruit and vegetables a day to reduce their risk of cancer and other diseases, there is little evidence looking specifically at a vegetarian diet.

Mr Key, whose findings are published in the British Journal of Cancer, added: 'More research is needed to substantiate these results and to look for reasons for the differences.'

His team followed the participants, just over half of whom were meat eaters, for more than 12 years during which time 3,350 were diagnosed with cancer. They looked at the rates of cancer among the vegetarians, and then compared them with those of the meat eaters.

Mr Key said: 'Our study looking at cancer risk in vegetarians found the likelihood of people developing some cancers is lower among vegetarians than among people who eat meat.

'In terms of what explains this we have to look at what other research is going on. For stomach cancer there is already quite alot of evidence that high intake of food such as processed meat may increase risk.

'Obviously, vegetarians who are not eating meat would not have that risk factor. It could be something about being a vegetarian that is protective, or alternatively it could be something about meat actually increasing the risk.'

Su Taylor, of the Vegetarian Society, said: 'This latest research adds to a growing body of evidence that vegetarians are less likely to get cancer.

'It could be they are simply more likely to stick to the recommended five portions of fruit and vegetables a day, thereby eating more roughage, or it could be more complicated than this.'

研究表明：素食可以把患癌症的风险降低几乎一半。

研究者对61,000名，年龄20到89岁的人群进行调查，发现吃素的人群总体患癌症比率率要低12%.

最显着的差异是血液系统疾病，素食者患上白血病和非霍奇金淋巴瘤只有45%.

研究表明素食者患白血病和非霍奇金淋巴瘤的几率只有45%.

素食者患胃癌和膀胱癌明显减少。

英国牛津大学，英国癌症研究所流行病学教授Tim Key说："世界总人口约三分之一的人可能患上癌症。如果按比率每100人中有33人患有癌症，那么，素食者这个比率会降到29%,而非素食者则达到了41%.

KEY称这个研究结果，还不足以劝告公众痛下决心改变饮食习惯，让他们以后均衡饮食。

虽然建议大众每天吃五份水果和蔬菜可以减少患癌症和其他疾病的风险，但没有充分的迹象表明有人在响应。

在英国癌症期刊的报告中KEY先生认为： "需要更多的研究来证实这些结果，并寻找产生差异的原因。"

他的研究团队观注素食者与肉食者癌症发病率，发现一半以上肉食人群中，吃肉超过12年的有3350人被诊断患有癌症。KEY先生说： "我们的研究发现肉食者患癌症的可能性要比素食者高。"

这一现象应如何解释？我们正关注其他正在进行的研究。已经有相当多的证据表明，例如吃加工过的肉食过多，可能会增加患胃癌的风险。很显然，素食者不吃肉不会增加患癌的风险。这对素食者来说可能是很重要的保护，吃素之所以重要是因为吃肉确实越来越不安全。

素食协会苏。泰勒说： "最新研究显示越来越多的证据---素食者不太可能患癌症。他们可能坚持每天食用5份水果和蔬菜，并且吃更多的粗粮，也可能原因比这更复杂。"