Descubren que el estres crónico impulsa el aumento de las celulas grasas en tamaño y cantidad

Un nuevo estudio indica que el estres produce obesidad al estimular las celulas adiposas.

Los investigadores encontraron que una molecula llamada NPY (neuropeptido Y) se libera en una persona afectada por el estres. El NPY desbloquea receptores en las celulas grasas causando el aumento de estas en tamaño y cantidad.

La buena noticia es que bloqueando los receptores especificos del NPY,  dicen los investigadores que se puede combatir la obesidad ocasionada por el estres, desarrollando nuevos medicamentos.

"Sabemos desde hace mas de una década que hay una conexion entre el estres crónico y la obesidad" dice el Doctor Herbert Herzog, del Instituto de Investicacion Médica Garvan en Sydney, Australia.

"Tambien sabemos que el NPY tiene gran influencia en otras afecciones crónicas inducidas por el estres, como sucede en la baja de las defensas contra las infecciones. Ahora nosotros hemos identificado el camino exacto, la cadena de eventos moleculares, que enlazan la obesidad con el estres crónico."

  
Stopping Stress From Turning to Fat

In the first part of the study, published in Nature Medicine, researchers fed stressed and unstressed mice either a standard diet or a high-fat, high-sugar, "comfort food" diet.

As expected, the mice on the high-fat, high-sugar diet gained fat while those on the standard diet did not. But researchers found the stressed mice on the high-fat, high-sugar diet developed more body fat than the unstressed mice fed the same diet.

Those results prompted researchers to look for differences in how the stressed mice utilized and stored fat.

"There is not much we can do about the increased levels of NPY caused by stress, but we can do something about the damage it causes," says Herzog.

They found that when they blocked the Y2 receptors for two weeks, the stressed mice lowered their abdominal fat deposits by 40%.

"Even more surprisingly, in addition to having flatter bellies, adverse metabolic changes linked to stress and diet, which include glucose intolerance and fatty liver, became markedly reduced. We do not know yet exactly how that happens, but the effect was remarkable," researcher Zofia Zukowska of Georgetown University says in the release. "Our findings suggest that we may be able to reverse or prevent obesity caused by stress and diet, including the worst kind of obesity; the apple-shaped type, which makes people more susceptible to heart disease and diabetes."

Fuente:
http://www.webmd.com/diet/news/20070702/stress-unlocks-fat-cells-ups-obesity