“My co-authors and I were truly surprised at how consistent the relation between meat-avoidance and the increased prevalence of mental illness was across populations,” study author Urska Dobersek, an assistant professor at the University of Southern Indiana, told PsyPost.
It should be noted that the researchers were unable to determine a cause for this link. One theory, however, is that there is a social stigma attached to veganism and vegetarianism, especially in places such as America.
Researchers looked at 18 different studies conducted around the world that examined the link between one’s diet and their mental health. Eleven of those studies found vegetarians and vegans had poorer psychological health than meat eaters; Three of the studies favored vegans and vegetarians, but the researchers noted the more “rigorous” studies were in favor of meat eaters.
Dobersek and her co-authors note that future studies should look at if the mental aspect could be one of the reasons why many people who adopt veganism or vegetarianism end up going back to eating meat (a December 2014 survey found that 84 percent of people who gave up meat eventually went back to doing so).
They’re also curious if there’s a nutritional reason for the link — in other words, they want to know if there’s something in meat that contributes to better mental health that you can’t get from fruits, vegetables, or grains.
