20º. That was the temperature early this morning in my lovely city of Boise, Idaho. Having grown up the balmy temps of southern California, adjusting to Idaho temps has been a challenge for me. I don’t necessarily like the extreme heat, but when the temperature is sitting in the 70’s I’m a happy camper.
There is one benefit I always think of when the temps are frigid and I just can’t seem to get warm: brown fat. You’ve probably heard the term, but might not understand the exact role it plays in our bodies.
What Is Brown Fat?
Brown adipose tissue, or brown fat, produces heat to keep our body warm when exposed to cold. This type of fat cell is denser than white fat cells, with more lipid droplets and mitochondria. Brown fat cells also contain more capillaries than white fat cells, so they need more oxygen.
Keep it cold on the outside to heat it up within. photo credit
What’s The Big Deal?
Because the purpose of brown fat is to provide heat in our bodies, it needs an energy source to do this. And guess what our body’s favorite source of energy is (in moderation, of course)? Sugar! When brown fat is activated by cold, it creates high amounts of glucose transporters to bring sugar in the blood to the brown fat cells for heat production, or thermogenesis. This process helps control blood sugar, big time.
Also, your body will turn white fat cells into beneficial brown fat cells when it has need. Cold creates that need. When your body shivers your muscles create a hormone called irisin (exercise creates this hormone as well), which triggers white fat cells to start producing heat (energy), which is a brown fat function.
Being cold has important health implications. The longer we’re exposed to cold, the more brown fat our bodies create, which has a pretty big impact on blood sugar management and metabolism. So don’t be afraid to turn your thermostat down to about 65º when you sleep. You’re doing your body good.
If you’re interested in more in-depth information, check out The Brown Fat Revolution by James Lyons.