Yes The Sun Can Be Damaging, But It May Also Prevent Certain Health Problems
You're right to be cautious about the sun. It can cause skin cancer, damage your eyes and make you look older. But with the right protection, getting at least 30 minutes of it a day may prevent Type 2 diabetes and metabolic syndrome - which increases the risk of heart disease and certain types of cancer, according to Cincinnati Children's Hospital Medical Center researchers.
Pediatric ophthalmologist and developmental biologist Richard Lang, Ph.D., has discovered sunlight stimulates fat cells deep inside the body. This produces the raw materials all other cells use for energy.
In a paper he published Jan. 21 in the journal Cell Reports, Lang details how reliance on the sun for thousands of years has developed genes that are light-sensing. They are called opsins and control a variety of functions, including the sleep-wake cycle.
It appears the sun can get through clothing. Lang says it doesn't have to be direct sunlight. You can be standing under a tree. "You can take precautions for the damaging parts of the spectrum in the usual ways," he says. "But I think this new work is helping us to see that we have to think a little bit more carefully about what different parts of the spectrum do."
When Should You Be Out In The Sun?
Lang finds it's especially important to be outside at dawn and dusk, but says that's difficult for a lot of people. Using the sun to maintain health would be a lifestyle change for many who spend much of the time indoors. Lang says lights just don't do it. He is focusing on opsin 5 - an ultraviolet light sensor expressed in the retina - and opsin 3, which is expressed in the skin cells that produce melanin.
Lang says artificial lights produce very little of the violet light that stimulates opsin 5 and produce lower levels of the blue light that stimulates opsin 3.
A Light That Is As Good As The Sun
The ultimate goal would be to develop a light that functions like the sun. Lang has convinced the people planning the new Cincinnati Children's Hospital to put spectrally tune-able lighting systems in every neonatal intensive care unit. They will be used for research purposes to improve the health outcomes by stimulating these light pathways.