New Study About Vegetarianism, by Kaleigh Rogers.

[Y]ou need to have a diet that is matched to your genes. For those individuals that carry the ‘vegetarian allele,’ our suggestion is to stick to the vegetarian diet because that’s what your ancestors ate and that’s what your ancestors adapted to. Too much meat or vegetable oil is not good for these people, because those foods also contain omega-3 and omega-6 fatty acids.

Kaixiong Ye and his colleagues have identified an allele—a gene variant—in some people whose ancestors maintained a primarily vegetarian diet. This allele allows these individuals to produce synthetic versions of omega-3 and omega-6 fatty acid, which are essential for brain function but can be lacking from vegetarian diets. While about 70 percent of South Asians had it, only 17 percent of Europeans (whose ancestors ate meat) did. Individuals with the “vegetarian allele” would be better off sticking to a vegetarian diet, so that they’re not getting double the dose of fatty acid from their diet and their body’s natural synthetic version.