Sunshine and fat burning: Research suggests vitamin D is crucial for your metabolic health

Sunlight has always been a part of keeping healthy thanks to how the human body produces vitamin D when exposed to it. But new research shows that exposure to natural sunlight also regulates how fat cells work in the body, improving our overall metabolic health.

Researchers discovered that a specific wavelength of light results in white fat cells releasing fatty acids into the bloodstream, allowing other cells to use the fat for energy. They found that light triggers the OPN3 gene, which prompts fat cells to release fatty acids. In animals, mice were found to be unable to warm up or burn fat well without this light.

Artificial lights don’t provide significant amounts of this type of light, but it is present in natural sunlight.

Scientists find genes that respond to sunlight

Light penetration into deep tissue is a new concept, even in the scientific community. However, senior author of the study, Richard Lang, said that he and his team were able to find opsins, or light-sensing genes, in different tissue types.

The specific light that scientists refer to in their study is the 480-nanometer wavelength of blue light. This wavelength is mostly available only through sunshine, which researchers believe is necessary for normal energy metabolism in mice, and possibly, in humans.

Lang said that artificial light does not provide the full spectrum of light that we can get from the sun. Of course, being outside is dependent on a lot of factors like the weather, but the benefits are well worth it.

When mammals are in a cold environment, their bodies adapt by shivering or burning fat to create heat. In a process called lipolysis, adipose tissues free fatty acids and glycerol into the bloodstream, and brown adipose fat takes them and uses them to generate heat.

There is evidence that supports the idea of activating brown adipose fat to protect us against metabolic syndrome, which is a collection of conditions that include hypertension, high blood sugar, abnormal blood lipids, and excess body fat around the waist.

The researchers created different environments to better study metabolism in mice. It was found that those without OPN3 used less energy and consumed less food and water. Despite being active as other mice, they still used less energy and carried higher fat levels.

Scientists are still at the beginning of this line of investigation, however, they have hypothesized that insufficient stimulation of the light-OPN3 adipocyte pathway is part of an explanation of the prevalence of metabolic deregulation in industrialized nations, where bright, unnatural lighting is the norm. (Related: Heliotherapy: Using sunlight to cure disease.)

Looking further in the future, doctors may one day be able to prescribe light therapy to people who are at risk of developing metabolic syndrome.

“Our modern lifestyle subjects us to unnatural lighting spectra, exposure to light at night, shift work, and jet lag, all of which result in metabolic disruption. It is possible that insufficient stimulation of the light-OPN3 adipocyte pathway is part of an explanation for the prevalence of metabolic deregulation,” Lang said.

New role of light

There are some wavelengths of light that can be harmful, but the study from Lang and his colleagues shows a different, healthy role for light exposure. With the data they gathered from mice, the team concluded that sunlight is required for normal energy metabolism.

Based on their current findings, insufficient stimulation of OPN3 adipocyte pathway led to the prevalence of metabolic deregulation in industrialized nations. It will take several years to flesh out the discovery, but theoretically, light therapy could become a method for preventing metabolic syndrome from developing into diabetes.

Read more about the benefits of sunlight at Health.com.

Sources include:

MindBodyGreen.com

MedicalNewsToday.com

APNews.com