The importance of sun protection to prevent photoaging is well known but another factor contributing to skin aging is often overlooked. Understanding the differences in the rate of the skin’s DNA repair mechanisms between skin of color and White skin reveals that skin aging between ethnic groups extends beyond the amount of melanin present.
Using the terms “DNA repair,” “skin aging,” and “ethnicity,” a search was performed on Medline and Embase databases. A total of 65 articles were deemed acceptable for inclusion in the review. The 65 articles were the narrowed down to 23 full-text studies.
The ethnic differences in photo aging included 4 subtopics: (1) skin cancer rates, (2) wrinkles, (3) DNA damage, and (4) apoptosis. In Whites, the rate of neoplasms was 35% to 45%, whereases the rates were 4% to 5%, 2% to 4%, and 1% to 2% in Hispanics, Asians, and Blacks respectively. Looking at wrinkles, the presence of wrinkles appears nearly a decade later in Asians than in Whites. Comparatively, Thai and Black women have a higher wrinkle fraction than East Asian women. UV-induced DNA damage, particularly in the lower epidermis, more prevented more effectively in darker skin. Additionally, darker skin shows more robust rates of DNA repair and UV-induced apoptosis.
All of these results suggest that, in addition to the amount of melanin present, the differences in rates of DNA repair play an important role in skin aging.
The researchers addressed some of the therapeutic treatments which can enhance DNA repair. Use of photolyases, oral Polypodium leucotomos, and other enzymes have all been found to aid in DNA repair following UV damage.
Understanding the impact of DNA repair mechanisms and how they vary amongst ethnic groups can help with the development of novel therapies, which extend beyond the current treatments of photoprotection. —Audrey Amos, PharmD
Reference
Chan S, Koo J. Countering skin aging through DNA repair enhancement: what can we learn from skin of color?. Poster presented at: American Academy of Dermatology Virtual Meeting Experience 2021; April 23-25, 2021; virtual.
