Chills and physical exercise can turn white fat into brown

2014/03/04 Jauregi Larretxea, Oihana - Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Medikuntza
• Biokimika

The research has been conducted in Washington by endocrinologist Paul Lee of the Garvan Medical Research Institute in Sydney, at the National Health Institute. And the results have been published in the journal Cell Metabolism.

“When we are cold our organism activates brown fat to produce heat. When this energy is not enough, the muscle contracts mechanically or begins to vibrate, causing chills, generating heat. So far we didn’t know how muscle and fat was communicating in this process,” explains Dr. Lee.

Thanks to this study, researchers have found that fats and muscles communicate through specific hormones. These hormones are the ones that turn white fat cells into brown ones.

“During the research we lowered the temperature from 18 to 12 °C gradually and during that time we took blood samples to the volunteers who participated in the research. Through special devices that we put on the skin, we measured the electrical activity of the muscles and saw that chills occurred,” explains doctor Lee.

This test showed an increase in the flow of two hormones by cold effect: irisine and FGF21 hormones. Later, during the tests carried out in the laboratory, the researchers observed that the white fat exposed to these hormones was burned faster and emitted heat, that is, it fulfilled the function of brown fat. Researchers believe that knowing the mechanisms to convert white fat into brown fat can help in the treatments of obesity.