Less Sunlight Exposure During Winter May Increase Body Fat

Several months of low exposure to sunlight may contribute to winter weight gain, according to researchers at the University of Alberta (UA).

The UA investigators discovered that the fat cells just beneath our skin shrink when exposed to the sun’s blue light.

“When the sun's blue light wavelengths - the light we can see with our eye - penetrate our skin and reach the fat cells just beneath, lipid droplets reduce in size and are released out of the cell,” said professor Peter Light, senior study author, and the director of UAlberta's Alberta Diabetes Institute. “In other words, our cells don't store as much fat.”

Although these findings may someday lead to light-based therapies for obesity, and related issues such as diabetes, the researchers note that getting sunlight exposure is not being recommended for weight loss. There are still too many unknowns, such as the intensity and duration of light required for fat reduction to occur.

The scientists also speculate that sunlight’s effect on fat cells may help determine the number of fat cells people manufacture during childhood—a number thought to remain constant into adulthood.

“Obviously, there is a lot of literature out there suggesting our current generation will be more overweight than their parents and maybe this feeds into the debate about what is healthy sunshine exposure,” says Light.

Further, the investigators point out that fat cells close to the skin may function as a peripheral biological clock.

“It's early days, but it's not a giant leap to suppose that the [blue] light that regulates our circadian rhythm, received through our eyes, may also have the same impact through the fat cells near our skin,” said Light. Blue wavelength light may “set the amount of fat humans burn depending on the season. You gain weight in the winter, and then burn it off in the summer.”

The UA researchers were actually bioengineering fat cells to produce insulin in response to light when they noticed blue light’s effect on fat cells. They look forward seeing what other findings their discovery may generate.

Source:MedicalXpress?
Photo credit: Adam Tas