Sunscreen is regularly used to protect against skin cancer, but now researchers at Pennsylvania State University say it can also protect the skin’s blood vessel function from harmful ultraviolet radiation (UVR) by protecting dilation of the blood vessels.
Additionally, perspiration on the skin may provide protection to the skin’s blood vessels from sun damage.
The findings were presented at the Experimental Biology conference in Orlando, Fla., over the weekend.
Researchers studied the effect of UVR exposure with sunscreen or sweat on the nitric oxide’s ability to promote the dilation of skin blood vessels.
Participants with light-to-medium skin tone were exposed to UVR on one arm while the other arm served as a control.
The dosage of UVR was comparable to spending an hour outside on a sunny day, but without the reddening indicating a sunburn. Three sites on the UVR-exposed arm, of each participant, were randomly assigned one of three treatments:
one site received UVR only;
a second site received UVR with a chemical sunscreen on the skin; and
a third site received UVR with simulated sweat on the skin.
The UVR-only site was found to have less nitric oxide-associated vasodilation than in the control arm. However, the sunscreen, and sweat-treated, sites did not show these reductions in nitric oxide-associated vasodilation.
“Further, when sunscreen was applied prior to UVR, UVR exposure actually augmented [nitric oxide-associated vasodilation] compared to (the control arm), or when sweat was on the skin,” the research team wrote. “The presence of sunscreen or sweat on the skin may play a protective role against this effect (of UVR).”
Sun-related UVR is a known cause of skin cancer and premature skin aging. UVR is also known to reduce nitric oxide-associated dilation of skin blood vessels (vasodilation) by decreasing the amount of nitric oxide available in the skin.
“For those who spend a lot of time working, exercising or participating in other various activities outdoors, using sunscreen may protect not only against skin cancer, but also against reductions in skin vascular function,” wrote S. Tony Wolf, MA, the first author of the study, in a press release. Wolf is a Ph.D. student at Pennsylvania State University.