Cooler temperatures associated with better insulin sensitivity and higher metabolism
The temperature at which your thermostat is set might influence how your body is storing and burning fat, according to a new study from the Garvan Institute of Medical Research.
Cooler temperatures seem to spur the growth of brown fat, which helps to burn energy and generate heat. Brown fat also has protective benefits against diabetes and obesity.
Blood sugar benefits
Endocrinologist Dr. Paul Lee included five healthy men in the study who were exposed to four 30-day periods of specific temperatures.
The men went about their daily lives as normal but spent each night at the National Institutes of Health Clinical Centre in a temperature-regulated room.
During the first month, the rooms were set at 24 degrees Celcius (75.2 degrees Fahrenheit) - which is a "neutral" temperature at which the body isn't necessarily working hard to lose or maintain heat.
The second month, rooms were set at 19 degrees Celcius, moved back up to 24 Celcius the third month and then turned up to 27 degrees the final and fourth month.
At the end of each period, the participants were evaluated for metabolic health and given PET/CT scans to measure their amounts of brown fat, muscle mass and tissue metabolic changes.
Results
Despite the season during which the temperature changes were carried out, researchers found that brown fat increased with cooler temperatures and decreased when the rooms were set hotter.
Additionally, the cold seemed to help improve insulin sensitivity - suggesting that people with more brown fat need less insulin after eating to bring their blood sugar levels back to a healthy place.
"The improvement in insulin sensitivity accompanying brown fat gain may open new avenues in the treatment of impaired glucose metabolism in the future," Lee said. "On the other hand, the reduction in mild cold exposure from widespread central heating in contemporary society may impair brown fat function and may be a hidden contributor to obesity and metabolic disorders."
Lee's previous work has shown that people who have more brown fat stores tend to have lower blood sugar levels.
"The big unknown until this study was whether or not we could actually manipulate brown fat to grow and shrink in a human being," he explained.
Results are published in the journal Diabetes.
Source: Garvan Institute of Medical Research
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