Calorie-burning fat and your brain

If you follow obesity news, you may have heard of a type of energy-burning “good fat” known as brown fat, which scientists think may have potential to battle a growing epidemic of excess body fat. Researchers at Yale School of Medicine have moved one step closer to realizing this possibility by discovering the brain’s role in turning white energy-storing fat into brown energy-burning fat.

Adipose, or fat, tissue is made up of two kinds of fat: brown fat and white fat. White fat stores energy in the form of triglycerides, while brown fat actually burns this energy by releasing it as heat. An excess of white fat results in obesity, while brown fat protects against the condition. Babies are born with brown fat that keeps them warm, but humans lose this fat as they age.

Research has shown that white fat can be transformed into brown fat, meaning people might be able to regain some of this “good” fat to help them burn energy and lose weight. The Yale School of Medicine researchers found that a molecular process in the brain of mice can control the transformation of white fat to brown fat. They recently published these findings in the journal Cell earlier this month.

The process involves AgRP neurons in the hypothalamus of the mice, which are known to promote hunger and decrease whole-body energy expenditure, according to Xiaoyong Yang, who is a lead author on the study. When fasting causes the activation of AgRP neurons, the neurons suppress the “browning” of fat. However, when these neurons are prevented from being activated, “browning” is promoted, protecting mice against diet-induced obesity and insulin resistance.

In the future, scientists might be able to develop a way to interfere with the signal sent from the brain to the fat cells, which could cause the body to burn fat rather than store it, Yang explained to me via email.

Although this strategy isn’t ready to help you burn off the Halloween candy you eat this weekend, it’s encouraging to know that we’re making progress on the road to better understand and manage obesity.