The Science of Skin Color
Skin colors vary, and those variations change our skin’s reaction to the world around us. Understanding the science that drives our skin color – and the process that creates it – allows us to grasp both the differences in our skin, as well as the universal truths that always apply.
What Determines the Color of Skin
Our skin’s unique color profile is born from a combination of melanin - a natural pigment found in the skin - as well as the size of the organelles that house it, called melanosomes. Melanin itself is produced by melanocytes - cells that live in the bottom layer of the epidermis. Each of us have an identical number of melanocytes – approximately 3000 per square millimeter of skin, but the amount of melanin they produce can be vastly different.
The amount of melanin our melanocytes produce, paired with the size of our melanosomes, is the recipe that results in our skin color.
Factors of Melanin Production
Melanin is produced during a reaction catalyzed by tyrosinase, a naturally-occurring enzyme found in the skin tissue. Without it – when tyrosinase is blocked – melanin can’t be produced. At times, this can be done intentionally with certain products to treat and prevent dark spots and skin discoloring. The formulas we select for our skin can have a direct affect on our melanin production and, in tandem, our skin coloring.
The greatest influence on melanin production, and our skin pigmentation process as a whole, is our genetics. While the structure of melanin is a commonality for all skin types, how it is activated and distributed among the cells in the epidermis varies between lighter skin and melanated skin. Our genetic traits play a key role in the latter two.
But one of the most substantial non-genetic factors that influence skin pigmentation is exposure to sunlight1. UV light exposure causes an increase of melanin production in the skin, leading to skin darkening – but it also means that outer skin cells are vulnerable to damage in the process. Temporary darkening caused by sunlight will fade when the damaged cells are replenished with new melanocytes.
Melanin in Dark Skin Versus Light Skin
The most substantial differentiators between light skin and dark skin are:
- The amount of melanin produced
- The size of the melanosomes
- The way melanosomes are distributed in the cells of the Epidermis
In lighter skin, melanosomes are smaller and are grouped closer together during cell distribution. In darker skin, melanosomes are larger and spaced further apart when disbursed to the epidermis cells – the keratinocytes.
It’s been scientifically determined that darker, melanated skin has significantly more resistance to UV light damage, attributed mainly to naturally higher levels of melanin production2. This is seen in the tendency of lighter skins to experience burning of the outer cell layers more frequently than darker skin. Darker skin doesn’t take on the same red tone we see with common sunburns on lighter skin tones.
Melanated Skin and Hyperpigmentation
Melanated skin is not one-dimensional. It comes with a set of unique challenges - one of the most common being hyperpigmentation. Often caused by an over-production of melanin in the skin, hyperpigmentation is a constant consideration for melanated skin. Some variations are caused by environmental factors, like sunspots. Others can surface from more deep-rooted causes like melasma, a condition where hyperpigmentation occurs due to hormonal changes and imbalances in the body.
The key to managing hyperpigmentation is incorporating a balance of healing properties, skin barrier protection, and melanin regulation in your skincare routine. It doesn’t take multiple products or a complex, complicated regimen - it takes grounded knowledge of our skin’s unique pigmentation process and the formulas that will provide it with targeted support.
The relationship between melanin production and skin pigmentation is an irrefutable one. It influences both the challenges we face with our distinct skin type, and how we manage then. But differences aside, all skin finds common ground in our melanocyte structure – which makes understanding your skin’s process an integral part of choosing the right products and regimens for your skincare routine3.
Citations
1Barsch, Geoffrey S. Unsolved Mystery: What Controls Variation in Human Skin Color? PLoS Biology. Vol 1: Issue 1.
2Miyamura et al. Regulation of human skin pigmentation and responses to ultraviolet radiation. Blackwell Munksgard, 2006.
3Baumann, Leslie. How Does Skin Make Color? 2020. https://lesliebaumannmd.com/how-does-the-skin-make-color/
