With the cooler weather approaching, it will become easier to “cool” your sleeping environment, and recent research shows there are added benefits to sleeping in a cool environment besides more restful sleep.
Researchers recently published a study in June issue of Diabetes: http://www.ncbi.nlm.nih.gov/pubmed/24954193
This study looked at the physiological effects on the human body when the sleeping environment was changed. Researchers affiliated with the National Institutes of Health persuaded five healthy young male volunteers to sleep in climate-controlled chambers at the N.I.H. for four months. The men went about their normal lives during the days, and then returned at 8 pm every evening. All meals, including lunch, were provided, to keep their caloric intakes constant. They slept in hospital scrubs under light sheets.
For the first month, the researchers kept the bedrooms at 75 degrees, considered a neutral temperature that would not prompt moderating responses from the body. The next month, the bedrooms were cooled to 66 degrees, a temperature that the researchers expected might stimulate brown-fat activity (but not shivering, which usually begins at more frigid temperatures). The following month, the bedrooms were reset to 75 degrees, to undo any effects from the chillier room, and for the last month, the sleeping temperature was a balmy 81 degrees. Throughout, the subjects’ blood-sugar and insulin levels and daily caloric expenditures were tracked; after each month, the amount of brown fat was measured.
This is important because brown fat, unlike the more common white stuff, is metabolically active. Experiments have shown that it takes sugar out of the bloodstream to burn calories and maintain core temperature.
The cold temperatures, it turned out, changed the men’s bodies noticeably. Most striking, after four weeks of sleeping at 66 degrees, the men had almost doubled their volumes of brown fat. Their insulin sensitivity, which is affected by shifts in blood sugar, improved. The changes were slight but meaningful, says Francesco S. Celi, the study’s senior author and now a professor at Virginia Commonwealth University. “These were all healthy young men to start with,” he says, “but just by sleeping in a colder room, they gained metabolic advantages” that could, over time, he says, lessen their risk for diabetes and other metabolic problems. The men also burned a few more calories throughout the day when their bedroom was chillier.
So until the temperature really drops, maybe turn your thermostat down a bit while you are sleeping for a restful night of sleep and added health benefits. If you have any questions about this article or how an exercise program might improve your metabolism, please feel free to contact me at: [email protected]