BOSTON — Could “chilling out” help millions of people battling obesity and the diseases it can cause? Researchers from the Joslin Diabetes Center say cold temperatures may reverse chronic inflammation, which is a contributor to obesity and metabolic diseases like diabetes. It can also stimulate the production of molecules important for weight loss.
Low-grade, chronic inflammation is an accumulation of immune cells in insulin-sensitive tissues. When study authors exposed obese mice to cold temperatures, their inflammation reduced, and they saw improvements in insulin sensitivity and glucose tolerance. The process depended on brown adipose tissue, or “good” fat, that produces a molecule called Maresin 2 when exposed to the cold. Brown adipose fat also uses up stored energy, potentially helping with weight loss and metabolic health.
“Extensive evidence indicates that obesity and metabolic syndrome are linked with chronic inflammation that leads to systemic insulin resistance, so interrupting inflammation in obesity could offer promising therapies for obesity-related disease,” says Yu-Hua Tseng, PhD, a senior investigator in the Section on Integrative Physiology and Metabolism at Joslin Diabetes Center and professor of medicine at Harvard Medical School, in a media release.
“We discovered that cold exposure reduced inflammation and improved metabolism in obesity, mediated at least in part by the activation of brown adipose tissue. These findings suggest a previously unrecognized function of brown adipose tissue in promoting the resolution of inflammation in obesity.”
Stabilizing Maresin 2 could cure metabolic diseases
Researchers fed mice a high-fat diet comparable to the typical “Western” diet in America. When the mice entered a 40-degree Fahrenheit environment, the researchers noticed the animals’ insulin sensitivity and glucose metabolism improved and their weight dropped compared to animals in a neutral climate. Mice in a warmer room did not need to produce heat to maintain their core body temperature. Results show there was an improvement in inflammation among the colder mice, according to inflammatory markers in their bodies.
“We found that brown fat produces Maresin 2, which resolves inflammation systemically and in the liver,” says Matthew Spite, PhD, a lead investigator at Brigham and Women’s Hospital and Associate Professor of Anesthesia at Harvard Medical School. “These findings suggest a previously unrecognized function of brown adipose tissue in promoting the resolution of inflammation in obesity via the production of this important lipid mediator.”
The findings suggest that creating the molecule Maresin 2 could be helpful in therapy for people with obesity, metabolic disease, or other diseases involved in chronic inflammation. However, the natural version of the molecule breaks down easily in the body, prompting the need for a more stable version of it.
The study is published in the journal Nature Metabolism.