Here is how sun damages our skin: study

Researchers have discovered the mechanism through which ultraviolet radiation, emitted by the sun, damages our skin.

The study was published in the journal ' Mechanical Behavior of Biomedical Materials'.

What kind of ultraviolet radiation is the worst for our skin? And how exactly does the sun damage it? Those two questions are at the heart of a new study by Zachary W. Lipsky, a biomedical engineering PhD candidate at Binghamton University. The study was overseen by Assistant Professor of Biomedical Engineering Guy K. German.

Ultraviolet radiation which the human eye can't perceive is broken down into four categories depending on wavelength and photon energy. Previous studies have documented how each type of UV radiation penetrates to different depths into the skin and that prolonged exposure can lead to skin cancer, but exactly how it damages human skin in other ways has received less attention.

Researchers from the cosmetics industry have debated for years whether UVA is worse than UVB for causing photodamage, which leads to the early onset of wrinkles and increased tissue fragility.

The Binghamton study used samples of female breast skin, chosen because it is typically exposed only to low levels of sunlight that were subjected to various wavelengths of UV radiation. What Lipsky and German found is that no UV range is more harmful than another, rather the damage scales with the amount of UV energy that the skin absorbs.

A more significant discovery, however, is the mechanism for how exactly UV damages skin. The study shows that UV weakens the bonds between cells in the stratum corneum, the top layer of skin by affecting proteins in corneodesmosomes that help the cells to adhere together. That's why sunburn leads to skin peeling.

Building on the findings of this study, Lipsky and German are doing further research about how UV radiation affects deeper layers of the skin.

As those experiments continue, Lipsky said the most important takeaway, for now, is that skin protection is important no matter what season of the year it is.

"We're trying to push the message to use sunscreen not just for preventing skin cancer, but also to keep the integrity of your skin so you don't get infections or other problems," Lipsky said.