Some high-end sunscreens say they can actually repair sun-caused DNA damage, a claim Wired's Robbie Gonzalez has taken a look into.
"That's … a bold assertion. To protect your genetic code from the structural harm that can lead to skin cancer is one thing — to actively correct that harm is another challenge entirely," Gonzalez writes. Additionally, he notes that when he asked the University of Texas Southwestern Medical Center's Errol Friedberg about it, Friedberg wanted to see more data.
As Gonzalez dug into it, he found that there are some studies that indicate that DNA repair enzymes like UV endonucleases and photolyases could be applied to the skin and boost the repair process. But the enzymes aren't included in all sunscreens, he says, because of their cost — and one company sells the enzymes.
In addition, he writes that one of the people who first noticed this ability, Daniel Yarosh, tells him that the enzymes and sunscreen might be best applied separately, as the enzymes need to sink below the skin, while sunblock needs to stay at the surface.
"But in the absence of more research, it's difficult if not impossible to say which formula is best — let alone which is most worth the several-hundred-percent premium over the affordable stuff," Gonzalez adds.