Sunlight continues to damage skin hours after exposure, study finds

BURBANK, Calif. (KABC) -- Walking at lunch is the only time Ernesto Romero says he gets to enjoy the sun.

"I do what I can to protect myself as much as I can while I'm outside," Romero said.

But we may all want to do more. A new study has revealed the sun's ultraviolet rays continue to do damage well into the night.

Yale School of Medicine researchers call this process "dark damage." Scientists found melanin-producing melanocytes, cells that protect our skin from the sun, continue to act like they're still being exposed to UV light even when they're not.

"The sun damage continues to happen in your cells on a DNA level for several hours," said dermatologist Dr. Shirley Chi, which is why getting sunburned can be so dangerous.

"What do you do about that then?" Romero asks.

We may want to change our behavior. Chi says, knowing this, we can spend less time outdoors and continuously reapply sunscreen when we are in the sun.

"On top of wearing sunscreen during the day, maybe we will, in the future, have to wear cream after our sun exposure to prevent further DNA damage in the evening hours," Chi said.

And for even more protection, Dr. Chi says, scientific research shows antioxidants may help.

"Blueberries and green tea can prevent antioxidation and we also know that you can put that on your skin in the form of vitamin A retinol and vitamin C and other antioxidant ingredients," Chi said.

The report in the journal Science is eye-opening but still preliminary. So for now, Romero says he might cover his head more often and keep this information "under his hat."

"Me personally, my rule of thumb is as long as you do everything in moderation you should be OK," Romero said.

Now that researchers know about this new way the sun can cause DNA damage, the next step is to look for treatments that can interfere with it.