Melanin is a substance present in the skin that produces pigment. Each person will have a different amount of melanin in their skin. This variation is due to genetics and other factors.
In this article, we discuss the function of melanin.
We also look at its benefits and whether or not a person can have too much or too little of it in the skin.
What is melanin?
Melanin is a substance in the skin that produces skin pigmentation. Scientists have identifiedthree formsof melanin in humans:
- eumelanin
- pheomelanin
- neuromelanin
Eumelanin and pheomelanin are in the epidermis, which is one of the layers of the skin. By contrast, neuromelanin is present in the brain.
Melanocytes are the cells that produce eumelanin and pheomelanin. Cells known as keratinocytes then carry melanin to the skin surface.
In people with dark skin, melanocytes produce more melanin than they do in people with light skin tones.
What is melanin’s function?
Melanin has a variety of biological functions,such as:
- pigmentation of the hair
- pigmentation of the skin
- protection of the eyes and skin from sunlight
Melanocytes produce melanin in the so-called basal layer, which is the innermost layer of the epidermis. Keratinocytes then carry melanin to the skin surface.
Differences in skin pigmentation between people are due to the ratio of eumelanin to pheomelanin, as well as the number of melanocytes.
Pheomelanin is responsible for the pinkish color of the lips, nipples, vagina, and penis glans.
Different hair colors result from different proportions of various forms of melanin. For example:
Hair colorMelanin type and amountblacka large quantity of eumelaninbrowna moderate quantity of eumelaninblonda very little quantity of eumelaninredprimarily pheomelanin, with only a small quantity of eumelanin
Benefits
Melanin has a variety of beneficial properties, including:
Protection from UV light
Melanin is aUV-absorbing agentand is able to protect the skin against the effects of UV light on the skin’s surface. It also offers protection against UVB and blue light.
Eumelanin protects the skin from UV light, whereas pheomelanin does not.
As a result, people with more pheomelanin, such as those with blond or red hair and light skin, are more likely to experience sun damage.
Protection against reactive oxygen species
Melanin also hasprotective effectsagainst reactive oxygen species (ROS). These are byproducts of cellular processes within the body.
A2012 reviewnotes that when there is an accumulation of ROS in the cells, they can cause cellular damage and stress. ROS has links to aging, cancer, and diabetes.
Melanin is able to pick up ROS that form when UV light stimulates oxidative stress on the skin.
Other benefits
Some research on animals has also indicated other potential benefits of melanin.
For example, a 2016 study on rats found that herbal melanin may be able to prevent the formation of stomach ulcers. This suggests that melanin could play a role in the protection of the gut.
Additionally,previous researchalso showed that melanin may contribute to the reduction of inflammation in the body, preventing injuries to the liver. It may also play a role in the immune system.
What affects melanin levels in the skin?
The amount of melanin in the skin will vary from person to person. Genetics plays a dominant role in how much melanin there is in a person’s skin.
Melanocytes house melanin in cells called melanosomes. The amount of melanin in the skin is aresultof the quantity and distribution of melanocytes.
A2020 articlenotes that skin pigmentation differences are due to the number of melanocytes present in the skin, as well as the ratio of eumelanin to pheomelanin.
Typically, those with light skin have melanocytes that have clusters of two or three melanosomes.
In contrast, those with dark skin generally have individual melanosomes that can also produce melanin for keratinocytes more quickly.
Other factors that can affect the level of melanin in the skininclude:
- age
- UV light exposure
- inflammation
- changes in hormone levels
Can a person have too much melanin, and can they decrease it?
It is possible for a person to produce too much melanin within the body. Experts call it hyperpigmentation. It can occur due to certain conditions or the presence of excess melanocyte-stimulating hormone.
Some factors that can increase the amount of melanin in the skin include:
- Addison’s disease
- hemochromatosis, which is a condition that causes the body to absorb too much iron from food
- pregnancy
- sun exposure
Can a person lower melanin levels?
Treatment options are available for hyperpigmentation.
For example, daily application of sunscreen with an SPF of 50 or higher can help minimize the effects of UV light on the skin.
Additionally, people can use topical treatments, such as:
- hydroquinone
- L-ascorbic acid
- azelaic acid
- corticosteroid creams
- retinoid creams
- glycolic acid
A person should consult a healthcare professional before using any topical treatments, as these could have side effects, such as increased sensitivity.
Learn more about treatment for hyperpigmentation here.
Can a person have too little melanin?
At times, a person can have too little melanin in the skin. This results in the skin becoming lighter. Healthcare professionals may refer to this as hypopigmentation.
Two examples of hypopigmentation are vitiligo and albinism.
Vitiligo is a skin condition that results in white patches of skin due to the loss of melanocytes.
Albinism is a genetic condition that causes people to have very little or no melanin pigment in the eyes, skin, or hair.
Can a person increase melanin levels?
There does not appear to be a safe way to increase the amount of melanin in the skin.
Although tanning is an indication that the skin is releasing melanin, it is not a safe way to increase melanin levels. The Skin Cancer Foundation notes that tanning increases the risk of developing skin cancer.
Learn more about increasing melanin levels here.
However, a person can consume certain nutrients to help the skin defend itself from UV damage.
According to2018 research, antioxidants may have the potential to increase the amount of melanin in the skin.
Melanocytes create melanin through the process of melanogenesis, which is also an oxidative process that produces ROS. Antioxidants are able to relieve this oxidative stress and reduce cellular damage.
Foods high in antioxidantsinclude:
- garlic
- bay leaf
- cinnamon
- red chili
- pomegranate
Depending on what is causing the hypopigmentation, there are some treatment options available.
For example, vitiligo treatment can include using sunscreen and phototherapy.
Summary
Melanin is a substance that melanocytes produce in the skin surface, which results in skin pigment. Each person will have a different amount of melanin in their skin.
The amount of melanocytes and the ratio of the forms of melanin in the skin dictate how much melanin is present.
Some conditions and environmental factors can decrease or increase the amount of melanin in the skin.
Additionally, methods are available to either lower or increase melanin levels in the skin. However, a person should consult a healthcare professional before considering any treatment options.