The Hispanic population in the United States saw a steady increase in growth in the new millennium, reaching a record high estimate of 59.9 million persons in 2018.1 With this increase in population, dermatologists need to be aware of the specific needs and strategies for skin care in this patient group. General dermatologic recommendations include daily photoprotection, but the evidence has typically been gathered from studies of Fitzpatrick phototypes I and II, leaving out darker, melanin-rich skin from results and preventing a greater breadth of clinical knowledge.
A research group, comprised of experts at the Vitiligo and Pigmentation Institute of Southern California in Los Angeles, department of dermatology at Howard University in Washington, DC, and L’Oreal Research & Innovation (Paris, France, and Clark, NJ), sought to determine the benefits of long-term daily use of broad-spectrum sunscreen in Hispanic female patients with phototypes IV and V. The study found significant clinical improvements in dyschromia-related parameters (ie, skin tone, hyperpigmentation, dark spots) on multiple areas of the face (ie, forehead, temple, crow’s feet, under eye, cheeks) at quarterly timepoints compared to baseline in the study group that applied sunscreen daily.2 Significant benefits to aging parameters, including fine lines, texture smoothness, and overall skin quality, were also demonstrated in the experimental group.
Among the research group was Qian Zheng, MD, PhD, assistant vice president of Advanced Research Americas of L’Oreal Research and Innovation. Dr Zheng discussed the study and its findings on behalf of the research team.
Q. Why did you and your team decide to study the benefits of sunscreen among the Hispanic population? How does it address an important gap in understanding the benefit of sun protection among skin of color populations?
A. At L’Oreal Research & Innovation, we focus on our diverse consumer needs and have adapted to the demographic shifts seen in the United States and worldwide. Over three-quarters of the world’s population is made up of individuals with phototype III and above.
Particularly in the United States, the skin of color population is increasing, driven largely by a fast-growing Hispanic population. While many current products might not take into consideration the specific skin care and photoprotection needs of this patient group, there are also other factors that are important to note and address:
- The skin cancer incidence among Hispanics has been growing;
- Engagement in sun-seeking behaviors without sufficient protection (eg, tanning, beach activities);
- Lack of sunscreen usage due to some unfavorable product formulation (concerns about oily skin or clogging the pores, white cast residual after application, etc); and
- Lack of understanding of the benefits of sunscreen and false sense of security that skin with higher phototype does not need daily sunscreen use.
In the past, the majority of clinical studies focused on the benefits of sunscreen in cohorts with lower Fitzpatrick phototypes. This study by our research group provides the first long-term (1 year) characterizations of benefits gained in higher phototyped skin in terms of overall skin quality, pigmentary end points, and photoaging-related appearance, such as improvement in lines, spots, and skin tone. Importantly, histologic analysis through biopsies revealed the changes beneath the skin surface that cannot be seen but may manifest with time as aging signs. While this study was conducted in Hispanic patients with phototype IV and V, we expect these benefits can be observed across all individuals with skin of color regardless of ethnic backgrounds. Importantly, this study has helped shed light on why proper sunscreen use should be part of an important daily effort and not just for recreational occasions.
Q. You noted that this is the first study to provide evidence that daily sunscreen use (SPF30, PPD20) can be an effective option for protecting the dermal-epidermal junction (DEJ). Could you elaborate more on this finding and how it further supports the use of sunscreen to prevent and treat pigmentary disorders?
A. We believe effective daily sunscreen use can protect skin at all layers: stratum corneum, epidermis, DEJ, dermis, hypodermis, etc. The DEJ is unique and important as it acts as a link between two of the skin layers and helps to anchor the epidermis in place, thus providing significant biological benefits and mechanical cohesion. The DEJ is also notable as the site where melanocytes are anchored. When the integrity of the DEJ is disrupted by inflammation as a result of significant UV exposure, melanin has been found to be “trapped” in the dermis, which can result in long-lasting and hard-to-treat “stubborn” hyperpigmentation. By reducing the impact of UV damage on the DEJ through effective photoprotection, we could prevent premature aging and skin laxity, which are associated with the flattening of the DEJ, and we could also reduce the prevalence of pigmentation and blotchy patches on the skin.
Q. What are some limitations of your study, if any? What other research is needed to support and better recommend sunscreens and sunscreen use among patients with skin of color?
A. The study had a small sample size and was also limited to individuals with Fitzpatrick phototypes IV and V skin. This could be further extended across all Fitzpatrick phototypes. Also, while we extended the study period for a year, longer observations would likely provide more information on other molecular changes in the skin. In this study we focused on pigmentary and photoaging parameters, while additional observation on other clinical concerns could be carried out in the future.
In addition, it is important to have research on new molecular pathways that prevent/reduce pigmentary lesions and on identification of new topical agents that can complete the sun care routine, with not just protection from UV light but also against damage caused by visible and infrared light. This will help extend daily protection beyond UV for individuals of all skin phototypes and build a more complete sun care strategy that is more inclusive for the skin of color population.
Q. What key takeaways from your study would you like to leave with our audience?
A. Unprotected and excessive sun exposures pose high risks for all people, regardless of skin color. This includes skin cancer risk, pigmentary disorders, and photoaging. Adding a broad-spectrum daily photoprotection step in our patients’ skin care routine is critical and an effective way to reduce such risks. At the same time, a good daily photoprotection routine can provide additional skin benefits to battle the signs of photoaging, including smoother, brighter, more even, and youthful-looking skin.
Q. Any other thoughts or comments you would like to add?
A. Prevention and protection play a key role in daily skin care routine, but these factors may have been underestimated by many. Increasing photoprotection education and advocating for proper sun care is important for patients/consumers with all skin types.
References
1. Flores A, Lopez MH, Krogstad JM. U.S. Hispanic population reached new high in 2018, but growth has slowed. Pew Research Center. July 8, 2019. Accessed May 1, 2020. https://www.pewresearch.org/fact-tank/2019/07/08/u-s-hispanic-population-reached-new-high-in-2018-but-growth-has-slowed/
2. Grimes P, Halder R, Verschoore M, et al. Long-term benefits of daily photo-protection with a broad-spectrum sunscreen in United States Hispanic female population. J Drugs Dermatol. 2020;19(3):236-242. doi:10.36849/JDD.2020.4836
