Researchers recently reviewed the molecular basis for the differences in skin across individuals and ethnicities and the need for personalized skin care.
The human skin is a unique organ with its outer layer exposed to the environment. Each individual’s bodily functions differ from one another, and the skin is no exception. However, there are millions of skin products in the cosmetic market, claiming the same benefits or solutions for the world population.
Researchers in the United Kingdom recently identified the key molecular factors driving the differences in the skin between individuals and across ethnicities in a recent review published in Clinical, Cosmetic and Investigational Dermatology.
Although the skin is visible to us, many internal biochemical and molecular pathways make up the skin. Individual differences and ethnic skin types are based on genes, which distinguish the skin’s structure and sensitivities to environmental factors. This produces variations in the skin’s responses to aging, damaging conditions, drug absorption, and sensitivities.
The researchers discuss three main molecular mechanisms behind these differences.
1. Genetic polymorphism
Genetic polymorphism refers to the variations in DNA sequences in different individuals. It can lead to changes in the proteins produce or the level of gene expression. This is normal, and also accounts for the different skin pigmentations within ethnicities, impacting the individual’s response to various forces in the environment.
2. Melanin
Melanin is a skin pigment located in the outer layer of the skin. It is the main determinant of skin complexion and ultraviolet (UV) sensitivity.
UV exposure can damage the skin, causing up to 80% of aging signs in Caucasian and Asian skin. Darkening of the skin from UV rays occurs from the redistribution of melanin and the creation of new melanin molecules.
Melanin has a protective function in the skin layers, decreasing DNA damage, and promoting cell death in cells that have DNA damage. Killing these cells prevent the potential development of cancer. The proteins involved in melanin production have also shown to regulate responses to UV exposure.
3. Structure and aging across skin types
Responses to environmental changes and aging are strongly influenced by factors such as DNA repair.
The difference in skin colour between ethnicities is due to the size of melanocytes, not the number. For instance, darker skin has larger melanocytes with more melanin pigments. This tends to provide more UV protection.
The researchers outline the main differences in the structure of the African, Asian, and Caucasian skin. The main points include:
- African skin has a thick stratum corneum, thde outermost layer of the skin. Thus, it has a stronger defence against the elements and microbial infections.
- Darker skin is more resistant to wrinkles, but are more prone to dyspigmentation
- African and Asian skin has thicker and compact dermis, the deeper layer of the skin.
- Asian skin has a delayed onset of wrinkles and solar damage but increased pigmentation and melanin with age
- Caucasian skin has disorganized elastic fibers and collagen in the dermis, leading to a quicker loss in elasticity and volume with age. It is also more prone to moisture loss compared to African skin.
The need for personalized skin care
Genetic variations between individuals make each person’s skin unique. The genetic makeup of an individual’s skin affects the melanocytes, structure, UV response, and aging process of the skin. This means that there are variations in drug absorption rates and sensitivities to different cosmetic products per individual.
Like personalized medicine, personalized skin care approaches will address this problem. Personalized skin care is growing, and has wide implications in the biomedical and cosmetic community. The researchers point to the need for establishing statistical tools to understand the genetic variations in the population that determine important skin proteins.
In the future, it may be possible to prescribe skin care based on your genetic makeup and hormonal and stress responses. This type of advancements in the field of personalized skin care will be able to address your skincare needs in a more precise manner.
Written by Alena Kim, HBSc
Reference: Markiewicz, E., & Idowu, O. (2018). Personalized skincare: from molecular basis to clinical and commercial applications. Clinical, Cosmetic and Investigational Dermatology, Volume 11, 161–171. http://doi.org/10.2147/CCID.S163799
