Could lack of sunlight be why we often gain weight in winter?
Published Thursday, January 11, 2018 12:27PM EST
Last Updated Thursday, January 11, 2018 1:18PM EST
If you tend to put on a little weight during the short days of winter, Alberta researchers may have stumbled on a reason why.
Researchers with the University of Alberta’s Alberta Diabetes Institute have discovered that the fat cells that lie just beneath our skin shrink when exposed to the blue light emitted by the sun, reducing their ability to store fat.
What this could mean is that the opposite holds true too: that our fat cells hold onto fat in low light levels, such as in the short days of the winter, and that the reduced sunlight we experience in northern climates might actually be promoting fat storage during winter.
The researchers caution their findings are preliminary. A lot more research is needed to understand how sunlight affects fat cells, which is why the team says they are not ready to recommend exposing skin to the damaging effects of the sun in a bid to lose weight. But they say their findings are intriguing and deserve more study.
The team made their findings almost by accident. They had been investigating how to use light to engineer fat cells in petri dishes to produce insulin, in the hopes of finding a potential treatment for Type 1 diabetes, says Peter Light, a professor of pharmacology and the director of UAlberta’s Alberta Diabetes Institute.
What they noticed, though, was that the fat cells responded to light by shrinking and releasing lipid droplets.
“We hadn’t expected to actually see that,” he told CTV News Channel Thursday. “It was a bit, I guess, of a serendipitous finding because we weren’t really looking for that pathway but we came across these results.”
It’s already well known that that sunlight we receive through our eyes affects our circadian rhythms, signalling to us when it’s time to wake and sleep. It’s why we are advised not to stare at digital devices before bed because the blue light of the screens confuses our bodies.
His team’s findings suggest sunlight may have the same impact on subcutaneous fat cells, perhaps as a part of an evolutionary process that signals the cells about when to store and shed fat.
“What we found is that it is exactly the same molecular pathway in our fat cells as that found in our eyes, so I think the two might be linked quite closely,” he said.
Light stresses the findings are preliminary but they provoke some interesting questions that other researchers will want to explore.
“What our work does is it opens up a new avenue for us and other researchers to now look at the effects of different types of sunlight and duration and intensity and see how much it affects the behaviour of fat cells to store fat and also release fat as well,” he said.
Light’s team’s findings are presented in the latest issue of Scientific Reports.