Hunger Hormone Seduces to Drinking

The main function of ghrelin, the so called hunger hormone, is to tell you when you're hungry, but it also works as a seductive component of drinking alcohol.

The main function of ghrelin, the so called hunger hormone, is to tell you when you’re hungry, but it also works as a seductive component of drinking alcohol. Studies with laboratory mice have shown ghrelin appears to play a central role for the development of alcohol addiction. In concentrations, too low for “reward center” in the brain, the latter doesn’t react on alcohol input and brain activity as such can lead into addiction. Researchers at University of Göteborg attribute ghrelin the key function in alcohol addiction.

Ghrelin is produced in the stomach and creates the feeling of hunger. Some earlier studies showed that ghrelin induces hunger of laboratory rats and human volunteers in about the same rate. The hunger hormone impacts the brain region of hypothalamus where the basic needs for living are controlled, between them also hunger and thirst. Ghrelin also affects some other regions of the brain, processing the rewards, related to thirst and hunger. Such processes play important role in development of eating and alcohol addiction.

The Swedish researchers injected hunger hormone directly in mice’s reward center of the brain. Animals then had the possibility to choose between two bottles, in one of which was water and in the other water-alcohol mixture. Mice with ghrelin injected were much more attracted to the bottle with the mixture, drinking to 45 percent more than mices without injection. Conversely, the mice were far less attracted to alcohol when researchers injected them substances that block the effects of ghrelin, probably because their brains produce less dopamine and the thrill for the alcohol no longer appeared. Dopamine is a reward hormone, which triggers feelings of happiness. And the conclusion of the researchers: Ghrelin stimulates the reward system in brain that produces dopamine which in turn allows feelings of happiness – which all together can lead to the addiction.

The researchers were able to exclude that he mice took alcohol because of the calories. Although some of the substances which blocked ghrelin, even encouraged the hunger feeling, mice decreased alcohol consumption. It seems as if ghrelin actually encourages addiction to alcohol in the first place and that its effect on hunger is far less expressed. If these results can be applied for the humans, this would be a promising approach for the treatment of alcohol addiction.