Judging by the headlines, a new Cornell study portends doom for vegetarians. Researchers found that in parts of the world where plant-based diets are commonplace, people tend to have a gene that increases the risk of deadly disease. Sounds dire, right? Before you swear off kale, consider what the study really says.
At issue is a genetic mutation that scientists are calling the "vegetarian allele." By chance, it probably occurred "once or twice perhaps a million years ago," says Tom Brenna, one of the study's authors. Because the mutation improves the body's ability to process fats from plants, evolution made it prominent, over a great many generations, in populations that consumed little meat and fish. Here's the problem: Our modern diets, which are high in bad fats, could theoretically turn the gene from an asset to a liability.
The mutation helps change vegetable oils into nutrients that our bodies need. Among them is omega-6 arachidonic acid, which, because humans need it to live, was a terrific thing for our genetic forebears. However, excessive levels of arachidonic acid cause inflammation, which promotes cancer and heart disease. And because modern-day meals include lots of dietary omega-6 fats, today the gene is a problem.