Most people don’t know that there are two types of fat. The stuff under your skin in your belly is very different from the stuff that lives between and cushions your organs. That second type, called brown fat, may be more critical to your overall health. In addition, it has the ability to release hormones that have unique properties. Now new research shows that we can activate brown fat by exercising. Why is that a big deal?
Brown vs. White Fat
Not all fat is created equal. For example, brown fat is the good stuff that lives between your organs, yet it seems to be more reclusive and difficult to activate than other types of fat. We do know that cold is one way to activate it. When it’s cold, brown fat releases hormones that stimulate calorie burning, which warms us up from the inside. Studies have found that people in colder climates tend to have more brown fat activity than those in hotter climates. In addition, leaner people have more brown fat activity than heavier people and children have more than adults, suggesting that without an overabundance of white fat to insulate us, the body still has a way of burning fat energy and staying warm.
When we think of weight gain or obesity, on the other hand, it’s white fat that is the big struggle. It’s this fat that is associated with diabetes, heart disease, metabolic disease, and many other health conditions. So when we lose weight, it’s the white fat that we’ve burned off. Despite this, everyone has significantly more of the white stuff than the brown stuff.
While both fats are energy storehouses and both release beneficial hormones, it was the release of the lipokine known as 12,13-diHOME from brown fat that was the focus of recent research. This is the hormone that increases in circulation in cold conditions to keep us warm. Researchers, however, have found that something else stimulates that release of this beneficial metabolism-controlling hormone from brown fat: exercise.
What Are Lipokines?
Known to improve cell response to insulin and suppress inflammation, lipokine hormones enhance lipid metabolism, decreasing the risk for metabolic syndrome (i.e., obesity, hyperlipidemia, high blood pressure, etc.). Our adipose (fat) tissue, a major storehouse for lipids, uses circulating lipokines, also known as “lipid chaperones,” to communicate with other body organs and keep metabolic processes in balance. In other words, our fat secretes hormones that help regulate our metabolism.
What you might not realize is that our bodies house different types of fat, or adipose, tissues. Let’s review a couple of these.
Study Suggests You Can Activate Brown Fat by Exercising
The purpose of the new study was to determine the source of the production of the specific lipokine hormone 12,13-diHOME. They began with an exercise study using mice and discovered an increase in the hormone during exercise. Once they determined exercise stimulated this hormone, researchers then removed the brown fat from the mice and performed a second exercise study. No 12,13-diHOME hormone was found in these mice, leading researchers to conclude that the hormone was indeed released from brown fat rather than white fat.
Researchers determined the brown fat, however, burned calories during exercise differently from how it burns them in cold conditions. During exercise—even just a single episode of exercise (two human cohort studies were also conducted to confirm this)—adipose and other tissues involved in metabolism actually communicate. This process also triggers the muscles to utilize the circulating lipokine as an energy source.
So in short, according to this study, exercise stimulates the release of the 12,13-diHOME lipokine from brown fat. This “lipid chaperone” circulates through the body, communicating with other metabolic tissues. The muscles take up the lipokine and use it as a source of fuel. So while we might not always have a ready source of frigid temperatures to activate our brown fat stores, regular exercise may be a way to keep it consistently producing that beneficial hormone 12,13-diHOME that helps keep our metabolism in check.
The upshot? What happens to your body when you exercise is pretty cool. All sorts of great things happen. If we now add that brown fat releases hormones that help balance the metabolism of the body, that’s one more reason to, as the Nike commercial used to say, “Just Do It”!