Making the stress-obesity connection
Poor diets full of convenience food, not enough exercise and chronic stress add up to a common lifestyle that is tailor-made for obesity problems. The mechanisms of the stress-fat relationship are currently being investigated in the laboratory, with a significant new finding reported in Nature Medicine (July 1, 2007). Researchers led by Zofia Zukowska at Georgetown University used JAX® Mice to explore how chronic stress affects weight gain. They found that mice subjected to both daily stress and a high-fat, high-sugar diet gained far more weight than if they were only subjected to one or the other. Indeed, they gained twice as much fat in their bellies as non-stressed mice fed the same diet. A closer look at the fat tissue revealed that the stress-diet combination spurred a significant increase in a messenger molecule—called neuropeptide Y (NPY)—and its receptor. The researchers were able to demonstrate that not only does NPY promote fat gain, but when blocked in mice it prevented fat accumulation and quickly shrank existing deposits. Tellingly, other research has also indicated a link between NPY and obesity in humans. While much work remains to determine if manipulating NPY in humans is safe and effective, the discovery promises to yield important advances in the effort to address the obesity epidemic.
