Keeping Cool Can Spur Metabolic Benefits and Keep You Fit: Implications for Diabetes

Want to stay fit? Then you'd better keep your cool. Scientists have found that ambient temperatures can influence the growth or loss of brown fat in people; in fact, cool environments can stimulate the growth of this type of fat, which can raise metabolism.

Brown fat, which is also known as brown adipose tissue, is a special type of fat that burns energy to generate heat. In fact, animals with abundant brown fat are protected from diabetes and obesity. Yet how brown fat is regulated in people and how it relates to metabolism has been somewhat unclear.

Now, scientists may have uncovered a few answers. The researchers recruited five healthy men and exposed them to four month-long periods of defined temperature. The men lived their normal lives during the day, but then went to the NIH Clinic Center, where they spent 10 hours in a temperature-regulated room.

For the first month, the rooms were maintained at 24 degrees Celsius, which is a "thermo-neutral" temperature. Then, the temperature was moved to 19 degrees and then back to 24 degrees for the third month. The fourth month was moved up to 27 degrees.

So what did the scientists find? It turns out that the brown fat in the men increased during the second month, which was the cool month. The fat then decreased during the fourth month, which was the warm month.

"The big unknown until this study was whether or not we could actually manipulate brown fat to grow and shrink in a human being," said Paul Lee, one of the researchers, in a news release. "What we found was that the cold month increased brown fat by around 30 to 40 percent. During the second thermo-neutral month at 24 degrees, the brown fat dropped back, returning to the baseline. When we put the temperature up to 27 degrees during the fourth month, the volume of brown fat fell below that of baseline."

The findings reveal that temperature plays a large role in the regulation of brown fat in the human body. This could be important for future studies on people with diabetes and could leads to further treatments for certain conditions in the future.

The findings are published in the journal Diabetes.