Why your skin gets older and can get cancer even without sunburn
UV-exposure, endogenous DNA damage, and DNA replication errors shape the spectra of genome changes in human skin
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Your skin collects tiny DNA mistakes over time—from the sun and from your body’s own aging processes. Even skin that never sees sunlight has sun damage written in its DNA. Darker skin blocks more of this damage.
Surprising Findings
UV-induced mutations are age-independent and found in sun-shielded skin.
People assume sun damage only happens where the sun hits—and that it gets worse with age. This study shows the damage is locked in early and lingers everywhere.
Practical Takeaways
Use broad-spectrum sunscreen daily—even if you’re indoors or have dark skin—because UV penetrates windows and causes lasting DNA damage.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Your skin collects tiny DNA mistakes over time—from the sun and from your body’s own aging processes. Even skin that never sees sunlight has sun damage written in its DNA. Darker skin blocks more of this damage.
Surprising Findings
UV-induced mutations are age-independent and found in sun-shielded skin.
People assume sun damage only happens where the sun hits—and that it gets worse with age. This study shows the damage is locked in early and lingers everywhere.
Practical Takeaways
Use broad-spectrum sunscreen daily—even if you’re indoors or have dark skin—because UV penetrates windows and causes lasting DNA damage.
Publication
Journal
PLoS Genetics
Year
2021
Authors
Natalie Saini, Camille K Giacobone, L. Klimczak, Brian N. Papas, Adam B. Burkholder, Jian-liang Li, D. Fargo, Ruimiao Bai, K. Gerrish, C. Innes, S. Schurman, D. Gordenin
Related Content
Claims (7)
As people get older, their skin cells naturally accumulate more DNA errors from normal chemical reactions inside the body—about 0.4 new errors per year—like a biological clock ticking.
Ultraviolet radiation exposure induces melanin production as a protective response, but this process simultaneously causes cumulative DNA damage in skin cells, leading to photoaging and increased risk of skin cancer.
Even skin that never gets direct sunlight still shows DNA damage from past sun exposure, and this damage doesn’t get worse as people get older—it just stays the same.
Even in skin that looks perfectly healthy, some cells already have the same DNA mutations found in skin cancers—but they’re rare and don’t cause cancer yet.
Every year, your skin cells make about 0.22 tiny copying mistakes when copying DNA in long repeating sequences—like typing 'AAAAA' and accidentally adding or losing an 'A'—and these mistakes build up as you age.