Will Sleeping Cool Actually Speed Up Your Metabolism?
Now, according to a new study, you can probably turn a good night of sleep into a great night of sleep . . . and it’s as easy as cranking the a/c.
Cold sleeping temperatures promote the production of brown fat — a thermogenic tissue, more similar to skeletal muscle cells than common white fat. Rodents have plenty of it to regulate body temperature because they can’t shiver effectively enough to stay warm. The same is true for human infants, who don’t shiver that well, either.
Until recently, it was thought that adults grow out of their brown fat, after all, we can shiver with the best of them. But it turns out that we have small deposits in our necks, along our spines, and a few other places throughout the body.
This is good news, sleepers! Brown fat is metabolically active, meaning that it burns calories to help maintains body temperature. Sleeping in colder temperatures kickstarts brown fat’s activity.
The study, conducted by researchers at the NIH, was based on results of work on brown fat in mice. Several mice, genetically predisposed to obesity, were kept in a 41 degree room for a week, which activated their brown fat and caused them to lose 47 percent of their total body fat.
To see if this applied to humans as well, the researchers found five healthy adult men who were crazy enough to agree to sleep in temperature controlled rooms at the NIH for four months. The temperatures fluctuated monthly: 75 degrees the first month, down to 66 the second, back up to that comfortable 75 for the third, and then cranked up to a sweaty 81 degrees for the last. Caloric input and expenditure, blood sugar and insulin levels, and brown fat stores were all tracked and measured.
The second month, when the men slept in the freezing 66 degree rooms, brown fat deposits doubled — a major metabolic advantage. They burned more calories day to day.
So the moral of this story: stay cold. You’ll sleep thinner and healthier if you build your stores of brown fat. You can pray for another polar vortex, or just make sure your air conditioner is working as hard as possible. Or you could buy a mattress that sleeps cool.