Choose: stress and depression or gluttony and obesity?

Ghrelin, the "hunger hormone", discovered in 1999, plays an important role in regulating the digestive process, mainly by influencing the synthesis of various enzymes. The content of ghrelin in the human body increases sharply (up to four times) in the absence of food, and after satisfying hunger decreases again.

The work of scientists from the Medical Center at the University of Texas at Dallas, published in the online issue of the journal Nature Neuroscience, opens up another area of research on the properties of ghrelin, concerning its effects on the psyche. A brief description of the work and the authors' comments can be read in the press release of UT Southwestern Medical Center “Hunger hormone increases during stress, may have antidepressant effect, researchers report".

Now it has become clear why some people who are stressed or depressed begin to overeat.

Ghrelin, according to the lead author of the article, Dr. Michael Lutter, coordinates the overall behavioral response of the body to stress and affects mood and the level of energy consumption by the body. Researchers have shown in experiments on mice that chronic stress leads to an increase in the concentration of ghrelin in the body. At the same time, the manifestations of depression and anxiety decrease, but a side effect of this beneficial property is increased food intake in experimental animals and, as a result, inevitable obesity.

The researchers suggest using the results to develop new treatments for obesity. Ghrelin, synthesized mostly in the gastrointestinal tract, transmits a signal to the brain about an insufficient level of food intake. If you block the transmission of such a signal, you can reduce food intake and increase the level of energy consumption by the body. However, anxiety and depression will increase at the same time. This fact was observed during the experiment. Another important observation is that in mice with an artificial gene mutation leading to a lack of reaction to ghrelin, the administration of ghrelin with a low–calorie diet did not reduce depressive or anxiety reactions.

Chronic stress significantly and permanently (for almost a month) increases ghrelin levels in both normal and genetically modified mice. However, the latter had obvious signs of depression and a decrease in food intake.

The researchers believe that the observations described by them, being transferred to the human body, are quite understandable from the point of view of the theory of evolution. Increasing ghrelin levels in the absence of food reduces anxiety and depression so that human ancestors can be more calm and ready to search for new sources of food. This gave them a clear advantage in the struggle for survival.

The discovery of the new role of ghrelin will help to develop ways to treat diseases such as anorexia nervosa, as well as create new treatments for obesity or depression.

Portal "Eternal youth" www.vechnayamolodost.ru according to the materials AllScience.ru

18.06.2008