Source: cnBeta
More than 40 percent of adult Americans are obese, a complex condition that increases the risk of diabetes, heart disease and several types of cancer. Obesity is a factor that can lead to other health problems by creating low-grade chronic inflammation and a buildup of immune cells in insulin-sensitive tissues. Scientists believe that reversing or “solving” this chronic inflammation may delay the onset of obesity-related diseases such as diabetes, and perhaps make weight loss easier.
Researchers from Brigham and Women’s Hospital and Joslin Diabetes Center found that in diet-induced obese mice , exposure to hypothermia improves insulin sensitivity and glucose tolerance while addressing obesity-induced inflammation. Their findings are published in a new paper in Nature Metablism.
The team also found that the mechanism depends on brown adipose tissue, commonly referred to as “good fat,” releasing a naturally occurring molecule called Maresin 2 in response to cold stimulation . Brown adipose tissue is known as an active endocrine organ because it secretes molecules that communicate with other tissues and manage metabolism. It also helps release stored energy and may promote weight loss and metabolic health.
“Abundant evidence suggests that obesity and metabolic syndrome are associated with chronic inflammation that contributes to systemic insulin resistance, so disruption of inflammation in obesity may provide a promising therapy for obesity-related diseases,” the study’s lead author said. “We found that cold exposure reduced inflammation and improved metabolism in obesity, at least in part,” said Yu-Hua Tseng, Ph. Mediated by activation of brown adipose tissue. These findings suggest that brown adipose tissue has a previously unrecognized function in promoting inflammation that resolves obesity.”
In two earlier experiments, Tseng and His colleagues found that brown fat may be activated by cold exposure to produce certain lipid mediators that control nutrient metabolism. In the current study, the researchers identified a novel role for a lipid mediator produced by brown fat in addressing inflammation.
In the current study, the researchers created a mouse model that develops obesity when given a standard high-fat, Western diet.
When these animals were exposed to a cold environment (about 40 degrees Fahrenheit), the researchers observed increased insulin sensitivity and glucose metabolism in these animals compared to control animals kept in a temperature-neutral zone Improved, and they lost weight — an ambient temperature where the body doesn’t need to generate heat to maintain its core body temperature.
What’s more, the scientists also noticed a profound improvement in inflammation, as measured by lower levels of a major marker of inflammation.
“We found that brown fat produces Maresin 2, which addresses inflammation in the system and in the liver,” said co-corresponding author Matthew Principal Investigator at Brigham and Women’s Hospital and associate professor of anesthesiology at Harvard Medical School “These findings suggest that brown adipose tissue has a previously unrecognized function in promoting resolution of inflammation in obesity by producing this important lipid mediator,” Spite said.
In addition, these findings It has also been shown that Maresin 2 could have clinical applications as a treatment for obesity, metabolic disease, or other conditions associated with chronic inflammation; however, the molecule itself breaks down rapidly in the body. Tseng and colleagues are seeking a more stable chemical analog for clinical use.
The team points out that a shortcut to improving metabolic health may already exist. Multiple human studies in Joslin and elsewhere have shown that exposure to mild low temperatures (50 to 55 degrees Fahrenheit) has been shown to be sufficient to activate brown adipose tissue and improve metabolism, although the mechanism is not well understood.