How Stress Induce Emotional Overeating?

Proenkephalin, a molecule found in the hypothalamus region of the brain is connected to stress and threat-induced emotional overeating, reveals a new study. These findings were observed by researchers at the Fralin Biomedical Research Institute at VTC and published in Nature Communications (1^✔ ✔Trusted Source
Lateral hypothalamic proenkephalin neurons drive threat-induced overeating associated with a negative emotional state

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Stress, Threat & Emotional Overeating - What is the Connect?

If you’ve had a near-miss accident in your car or suffered the intimidation of a menacing person, you’ve probably felt it — a psychological reaction to a threat called a fight or flight response. Your heart rate climbs, anxiety washes over you, and you might shake or sweat.

But hours after that stress passes, you may feel another response — a powerful desire for comfort food, that highly processed, high-fat stuff you know isn’t good for you. It can relieve stress and tension and provide a sense of control. Emotional eating following a stress-triggering interaction is familiar to many of us, and to scientists as well.

But how a threat signals your brain to want comfort food has been unknown.

“We don’t always eat because we are hungry and we have certain physical needs,” said Shin, who is also an assistant professor in the Department of Human Nutrition, Foods, and Exercise in Virginia Tech’s College of Agriculture and Life Sciences. “Whenever we get stressed or feel some threat, then it can also trigger our eating motivation. We think this molecule is the culprit.”

Shin and her research team began their study by investigating a small molecule, Proenkephalin. This molecule is common in multiple parts of the brain, but little research has examined its role in the hypothalamus. Shin suspected it played a role in stress and eating because the hypothalamus is a center for regulating eating behavior.

The lab exposed mice to the odor of cat feces. The odor of a natural predator triggered a threat response in the mice, and 24 hours later, the mice exhibited a negative emotional state, and overeating behavior, and neurons in their brains showed sensitivity to the consumption of high-fat foods.

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To confirm the role of the molecule in stress-induced eating, the researchers activated the same neurons artificially with light stimulating a genetically encoded molecule expressed in the neuronal cell’s membrane, without the predator scent, and saw a similar response. In addition, when they exposed the mice to the cat odor and quieted the reaction of the neurons expressing that molecule with the same technique, the mice showed no negative emotional state and didn’t overeat.

Reference:

1. Lateral hypothalamic proenkephalin neurons drive threat-induced overeating associated with a negative emotional state - (https://www.nature.com/articles/s41467-023-42623-6)

Source-Eurekalert