Is Vegetarianism Giving You Cancer? No, But Your Genes Might Yearn For Burgers


It’s pretty easy to misconstrue scientific research, especially when it makes a good headline. The Telegraph, for example, just yesterday announced that Long-Term Vegetarianism Raises Your Odds of Cancer. But that’s not what the study they’re discussing claims. Instead, what researchers at Cornell have found is far more fascinating and might have vast implications for your health we don’t fully grasp yet.

The study, with the gripping title “Positive selection on a regulatory insertion-deletion polymorphism in FADS2 influences apparent endogenous synthesis of arachidonic acid“, looks at arachidonic acid production across human genotypes. Arachidonic acid is an omega-6 fatty acid, cousin to the omega-3s you’re finding shoved into every food on the shelves these days. Generally, we get it by having our bodies convert linoleic acid into arachidonic acid.

Here’s where it gets interesting. We’ve known for a while that there are mammals, like cats, who can’t do this, and thus have to get their arachidonic acid from their diet. These are called obligate carnivores; even if they wanted to eat veggies exclusively, they couldn’t. But the Cornell studies show that our ability to convert linoleic acid depends heavily on our genetics, more so than we thought, and there are humans who biologically need to eat more meat, and conversely, there are humans who are hyper-efficient at this conversion and shouldn’t eat meat. Considering the distribution of these genetics, it seems that humans evolved to fit the diets they could eat; you’re more likely to find vegetarians among Southeast Asian peoples, for example, and genetics that prefer fish among coastal peoples.

That said, though, they’re not the absolute majority: According to the study, roughly 17 percent of Plains-dwelling meat-eaters would be better off with salads. This is where the cancer claims are coming from: Too much arachidonic acid can increase inflammation problems, which may in turn aggravate some cancers. But, as you can see, it’s more complex than that.

So, what should you take away from this, in terms of eating? This isn’t a free pass to stop eating vegetables, as there are a whole bunch of health benefits to plants that mean they need to be a part of your diet. But it also means any beef-eating under the influence is okay and might even be what your body needs. Long-term, this study will open the door to customized diets keyed to our specific genetics; you might go to the doctor and walk out with a list of foods that have to go in your mouth. But for now, the biggest takeaway is that there’s no one perfect diet for everyone, so we should all dial it back on the meat-eating and vegetarian hate alike.

(Via the Washington Post)