Brain cells that usually promote hunger are also activated by alcohol in a mouse study published in Nature Communications. The findings may help us to understand why alcohol consumption leads to overeating.
Alcohol consumption has been linked to overeating in humans, but the underlying causes are unclear as alcohol is high in calories, and calorie intake usually suppresses brain appetite signals. Denis Burdakov and colleagues identify the neural mechanisms that underlie this behaviour in mice. They show that major components of the brain’s feeding circuits are activated by alcohol. In an ‘alcoholic weekend’ test, mice were given alcohol at doses that are the equivalent of around 18 units (UK measurements) for three days, which led to a significant increase in food intake compared with the mouse group in which no alcohol was administered. The authors find that hunger-promoting Agrp neurons, which are part of the feeding circuit in the mouse brains, are also activated by alcohol. Moreover, abolishing activity of these neurons also eliminated alcohol-induced overeating. This shows that Agrp cell activity is essential for alcohol-induced overeating.
These results indicate that alcohol sustains fundamental appetite signals, offering new insights into overeating behaviours.