A vegetarian diet is associated with higher rates of allergies, cancer, and mental illness, as well as a poorer quality of life compared to carnivorous diets, according to a new study.

The research, published in February in the journal PLoS ONE, surveyed 1,320 Austrians, evenly portioned to four different nutritional groups: a vegetarian diet, a carnivorous diet rich in fruits and vegetables, a carnivorous diet less rich in meat, and a carnivorous diet rich in meat. Subjects were matched based on age, sex, income, education, and occupation. All information was attained through face-to-face interviews.

The results were bleak for vegetarians.

"Overall, vegetarians are in a poorer state of health compared to the other dietary habit groups," the authors reported.

Vegetarians suffered from higher rates of allergies, cancer, anxiety, and depression. They were also vaccinated less often than all of the other groups, and visited the doctor for preventative check-ups less frequently than subjects eating a carnivorous diet rich in fruits and vegetables.

But despite the findings, American meat-eaters should resist the urge to pester their plant-eating brothers and sisters. Why? For starters, the study has a host of inescapable limitations. All of the data, including diet information, is self-reported. Thus, we have no idea precisely what vegetarians or the various meat-consuming groups were actually eating. The data is also cross-sectional. "Therefore, no statements can be made whether the poorer health in vegetarians in our study is caused by their dietary habit or if they consume this form of diet due to their poorer health status," the authors admit. Moreover, the study was based in Austria, and the Austrian diet and lifestyle significantly differs from the American diet and lifestyle.

Even if the study wasn't severely limited, it wouldn't be enough to overturn prior evidence. In a 2009 review, the Academy of Nutrition and Dietetics (formerly the American Dietetic Association), the largest organization of food and nutrition professionals in the U.S., declared that "appropriately planned vegetarian diets, including total vegetarian or vegan diets, are healthful, nutritionally adequate, and may provide health benefits in the prevention and treatment of certain diseases." More recently, a 2012 review published in the journal Public Health Nutrition, found that vegetarian diets have not shown any adverse effects on health.

Source: Burkert NT, Muckenhuber J, Großschädl F, Rásky É, Freidl W (2014) Nutrition and Health – The Association between Eating Behavior and Various Health Parameters: A Matched Sample Study. PLoS ONE 9(2): e88278. doi:10.1371/journal.pone.0088278