Vegetarians are more likely to suffer from allergies, cancer and mental problems including depression and phobias.
The wide-ranging study on diet and health was carried out by the Institute for Social Medicine and Epidemiology (IFES) at the Medical University (Med-Uni) in Graz, Austria.
Study coordinator and epidemiologist Nathalie Burkert said that it had been a surprise when they had evaluated the data to discover that people who live a vegetarian or vegan lifestyle had a subjectively worse health situation than others who had a mixed diet. In conclusion, as well as suffering from allergies, cancer and psychological problems, the perceived quality of life vegetarians had was also generally lower.
She said: “We found the results from the data very exciting, which is why we decided to publish it.”
But she denied that the results meant vegetarians should once again start eating meat.
She said: “There have already been press releases claiming our results are an advert for the meat industry, but our study hasn’t proved that. We have already distanced ourselves from this claim as it is an incorrect interpretation of our data. We did find that vegetarians suffer more from certain conditions like asthma, cancer and mental illnesses than people that eat meat as well, but we cannot say what is the cause and what is the effect. There needs to be further study done before this question can be answered.
“What we did not look at was whether vegetarians opted for the diet because they had a lower quality of life or whether being a vegetarian caused the lower quality of life. This was not something that we evaluated.”
The healthiest diet appeared to be the so-called Mediterranean diet with lots of fruit and vegetables and a moderate consumption of meat.
She said: “It was clear from our results that a diet that includes a moderate amount of meat rich with fruit and vegetables was reflected in a generally healthier person. They had better health, and a better quality of life and fewer visits to the doctors. That was simply what the data portrayed, that those on a mixed diet had the advantages.”
But she said that the research also showed that there needed to be urgent further studies done on the relationship between cause and effect in relation to nutrition: “Vegetarians freely admitted that they seemed to go to the doctors often because of physical problems, although they less often went for check ups and immunisations.”
The study seems to contradict claims by example by Noble prize winner Harald zur Hausen said that eating red meat could cause cancer, but Burkert said the two studies did not contradict each other as her team had not looked at whether they actually ate red meat, or other meat like chicken and turkey.
She said: “We started off with 15,000 case studies and we divided these up into nutritional groups. We selected 343 vegetarians and we then looked at their ages, their sex and their social and economic background (SES), which included the level of education, the income and their career. We then compared the vegetarians with somebody who matched them in the other three nutritional groups.”
She added that although her study was focused on Austria she believed it was relevant for anybody considering their diet and said she would advise vegetarians that by opting not to eat meat they were running the risk that certain key elements might be missing from their diet.
She said it was possible for vegetarians to find substitute sources and that being a vegetarian was not in itself yet proven to be unhealthy, even though her study had shown that subjectively vegetarians were less healthy and felt that they had a lower quality of life than others who had a different diet.