Photoprotection may safeguard the molecular integrity of skin

Photo by Nataliya Melnychuk via Unsplash

Regular use of a sunscreen may do more than deflect ultraviolet (UV) rays—it could help preserve the molecular and epigenetic stability of human skin, according to new research.

In a study published in Scientific Reports, Agata Bienkowska and colleagues found that consistent sunscreen application can prevent many of the fundamental biological disruptions caused by repeated UV exposure. The findings build on decades of evidence linking UV radiation to sunburn, premature skin aging, and malignancy, but the researchers extend the argument for daily photoprotection into the molecular domain.

They examined skin biopsies from 32 women across four Fitzpatrick phototypes who were subjected to repeated moderate UV exposures. Samples were collected from untreated skin, skin exposed to UV light without protection, and skin pretreated with sunscreen. Using advanced molecular profiling, the team analyzed gene expression patterns and DNA methylation signatures—markers that reflect both immediate cellular responses and longer-term epigenetic regulation.

Unprotected UV exposure induced widespread molecular disruption, activating stress pathways central to DNA repair, immune regulation, and cell-cycle control. These perturbations aligned with the Hallmarks of Health, a framework describing biological processes that maintain physiological resilience. Broad dysregulation across these hallmarks suggested a rapid deterioration in the skin’s structural and functional stability.

In contrast, the use of sunscreen markedly reduced these molecular changes. Most gene expression shifts and epigenetic modifications triggered by UV exposure were prevented, preserving the stability of hallmark-associated pathways. The data indicate that sunscreens not only protect against visible photodamage but also curb the acceleration of epigenetic aging—an emerging biomarker of long-term tissue health. Although some residual molecular alterations remained, the overall preservation of genomic equilibrium was striking.

“The findings provide new insight into how photoprotection works at a molecular level,” the authors wrote. They emphasized that sunscreen’s benefits extend beyond preventing erythema and malignancy to maintaining the skin’s biological balance under chronic environmental stress.

Experts say this work underscores sunscreen’s role as a tool of preventive dermatology rather than a purely cosmetic measure. Identifying the pathways stabilized by sunscreen could inform next-generation formulations designed to reinforce molecular defenses and slow intrinsic skin aging.

The study reinforces the message that daily, consistent photoprotection is critical—not only to prevent visible damage, but to maintain the unseen molecular architecture that underpins skin health.