A new study on brown fat indicates that this kind of lipid helps eliminate basic and essential branched-chained amino acids, organic molecules that in large quantities can cause type 2 diabetes or obesity. This research opens the door to the study of new drugs against these diseases.

Brown fat, also known as brown adipose tissue, is a special type of body fat that activates when you feel cold. This fat, which is stored in various parts of the body such as the neck, clavicle, kidneys and spinal cord, is considered a heat organ. When the body feels cold, brown fat is activated using sugar and blood fat to generate heat in the body.

A team of researchers, led by Rutgers University, found that brown fat could also help the body filter and eliminate basic and essential branched-chained amino acids (BCAA) from the blood, including leucine, isoleucine and valine which are related to obesity and diabetes, if stored in large quantities.

BCAAs are found in foods such as eggs, meat, fish, chicken and milk, but also in supplements used by athletes to increase muscle mass. These substances are often beneficial for improving metabolism and performance in athletes. However, the excessive increase in BCAA levels is related to obesity and diabetes.

“BCAA supplements are beneficial for those who have active brown fat (that is, healthy people), but they can be harmful for those who do not have brown fat (that is, elderly, obese or diabetic people, as they have little capacity for eliminate them later),” argues  Sinc Labros Sidossis, professor at the University of Rutgers (USA) and co-author of the study published by the journal Nature.

In this way, this type of fat could help protect against obesity and diabetes because it works better than white fat to eliminate these amino acids. However, more studies are needed to examine why some humans have this type of fat and others do not, or how it can be activated, and if there are pharmacological interventions that can increase its amount in the body.

A protein is the key

The study found that a new protein, called SLC25A44, is responsible for controlling the rate at which brown fat removes amino acids from the blood and uses them to produce energy and heat, a mystery that had been trying to solve for more than 20 years.

“The existence of a BCAA mitochondrial transporter has been at stake for over 20 years, but it had not been identified. Now it would be very useful to find out how we can manipulate it so that it is able to eliminate as much BCAA as possible and thus improve metabolic health,” says the researcher.

Experts still need to determine whether the absorption of BCAAs by brown fat can be controlled by environmental factors —such as exposure to slightly cold temperatures (18 degrees) or the consumption of spicy foods— or by medications. “This could improve blood sugar levels that are related to diabetes and obesity,” Sidossis said.

 

Source: SINC