Damned if you do ...

Gregory Nemec

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Free radicals sure sound frightening. And they are, scientists say: the unstable molecules have been shown to damage the body’s cells and promote aging. For years, nutritionists have been teaching us to combat them by eating antioxidant-rich superfoods such as apples and nuts.

But a new study by Yale professors Tamas Horvath and Sabrina Diano, published in Nature Medicine, indicates that declaring war on free radicals may also lead to weight gain.

In an experiment with mice, the researchers found that suppressing free radicals decreased the mice’s ability to feel full after eating, thus encouraging them to overeat. Free radicals, they found, are crucial to activating the neurons in the brain that trigger satiety. “In an obese person, in order to decrease food intake, you need more free radicals in these specific neurons to make them eat less,” says Diano, an associate professor of Ob/Gyn, neurobiology, and comparative medicine. “That’s the problem.”

Horvath, the Jane and David W. Wallace Professor of Biomedical Research, says free radicals are part of a catch-22: they’re necessary to curb hunger pangs but also dangerous to your overall health if chronically elevated. That duality is why scientists have struggled to develop a treatment for obesity that has few adverse side effects, he says.

“Because prolonged free radical exposure leads to tissue damage, you may lose weight, but you will accelerate degenerative processes in your body and likely promote premature aging and death,” Horvath writes in an e-mail. But antioxidants aren’t necessarily the answer either. Because they reduce free radicals, foods like apples and nuts can leave people feeling hungry even after they’ve eaten, which may induce obesity.

Should we eat cupcakes instead—just to be safe?