Melanin is a term used to describe a large group of molecules responsible for many biological functions, including skin and hair pigmentation, as well as photoprotection of the skin and eyes. Thus, melanin plays an important role in determining hair, skin, and eye color. Genes, inherited from parents, largely dictate the amount of melanin. The greater the amount of melanin, the darker the eyes, hair, and skin will be.
In this article, we explain what melanin is, its main types, and how it influences skin health. We also present the benefits of this pigment and the conditions that can arise when melanin levels are imbalanced.
Table of Contents
What is melanin?
Melanin is a term that defines a group of natural pigments found in the human body. Melanocytes, the cells in the deepest layer of the epidermis (basal layer), and hair follicles produce melanin. This pigment gives color to the skin, hair, nose, inner ear, and choroid (the vascular and pigmented membrane of the eye, located between the sclera and retina).
Natural melanin levels are primarily determined by genetic factors. However, other causes can influence melanin production, such as:
exposure to ultraviolet light;
inflammation;
hormonal changes;
age;
skin pigment disorders.
Melanocytes house melanin in intracellular vesicles called melanosomes. The level of melanin in the skin is a result of the amount and distribution of melanocytes.
Melanocytes produce melanin in the basal layer, which is the deepest layer of the epidermis. Keratinocytes then transport melanin to the skin's surface.
Everyone has the same number of melanocytes, but some people produce more melanin than others. If cells produce only a little melanin, hair, skin, and eye irises can be very light. If cells produce more pigment, then hair, skin, and eyes will have a darker shade.
However, people with dark skin have melanosomes that are greater in number, larger in size, and more pigmented than those with light skin. This is why there are so many skin colors.
It is possible for a person to produce too much melanin in the body. This process is called hyperpigmentation and can occur due to certain conditions or an excess presence of a melanocyte-stimulating hormone.
Factors that can increase the amount of melanin in the skin include:
Addison's disease (a condition characterized by insufficient hormone secretion in the adrenal glands);
hemochromatosis (a condition that causes the body to absorb too much iron from food);
pregnancy;
sun exposure (tanning).
Sometimes, a person can have too little melanin in the skin, which is called hypopigmentation. Two examples of hypopigmentation are vitiligo and albinism.
Types of melanin
Although melanin is usually referred to as a single pigment, there are actually several types of melanin:
Eumelanin (contributes to hair, skin, and eye pigmentation);
Pheomelanin (contributes to hair, skin, and eye pigmentation, as well as lips, nipples, and other pink parts of the body);
Neuromelanin (exists in the human brain and contributes to the pigmentation of structures in this area).
Eumelanin and pheomelanin are produced in different amounts in the basal layer of the epidermis, in cells called melanocytes. In contrast, neuromelanin is found in the brain.
While eumelanin and pheomelanin control the colors of visible parts (such as skin, hair, and eyes), neuromelanin is responsible for the color of neurons.
Differences in skin pigmentation are due to the ratio of eumelanin to pheomelanin, as well as the number of melanocytes.
Eumelanin can be divided into several types of black and brown. Eumelanin levels influence hair and skin color. For example, a high level of black or brown eumelanin results in a dark hair color, while small amounts are characteristic of blonde hair.
Therefore:
people with black hair have a large amount of eumelanin;
people with brown hair have a moderate amount of eumelanin;
people with blonde hair have a very small amount of eumelanin;
people with red hair have equal amounts of pheomelanin and eumelanin.
On the other hand, neuromelanin can give a dark color to parts of the brain. Research suggests that the presence of this pigment can help prevent cell death in certain parts of the brain. The loss of neuromelanin has been associated with symptoms of Parkinson's disease.
When we spend time in the sun, the body produces more melanin. The substance absorbs light from UV rays and redistributes it to the upper layers of the skin. It also protects the genetic material stored in cells by blocking access to harmful ultraviolet rays.
However, melanin alone is not enough to provide skin protection against the sun. Therefore, it is recommended to apply sunscreen products every day, regardless of the season.
Melanin: benefits
Melanin is not only responsible for skin, hair, and eye pigmentation, but also offers protection to the body.
Protection against UV rays. Melanin helps protect epidermal cells (the outer layer of the skin) from ultraviolet light and blue light. This happens by absorbing UV light before it can damage the sensitive DNA of skin cells.
Thus, melanin is an agent that absorbs ultraviolet rays and is capable of protecting the skin against the effects of UV light on the skin's surface. Eumelanin protects the skin from UV light, while pheomelanin does not. As a result, people with more pheomelanin, such as those with blonde or red hair and fair skin, are more susceptible to sun damage.
Protection against reactive oxygen species. Melanin also has protective effects against reactive oxygen species, the so-called free radicals. These are by-products of cellular processes in the body. When there is an accumulation of reactive oxygen species in cells, they can cause stress, premature aging, and health problems such as diabetes and cancer. Melanin neutralizes reactive oxygen species by stimulating antioxidants and eliminating free radicals.
Without the intervention of protective compounds, such as antioxidants, these reactive oxygen species contribute to oxidative stress, which causes significant cellular damage.
There are indications that there may be other mechanisms of melanin's action in the body, such as the protection of the liver, intestines, and even the immune system. However, research on these potential actions is limited, so pigmentation and photoprotection remain the two main benefits of melanin.
Conditions associated with melanin
Generally, genetics determine the amount of melanin in hair, skin, and eyes, but there are two conditions people can suffer from if they don't have enough melanin.
Vitiligo is an autoimmune condition that occurs when the body does not have enough melanocytes. This causes a lack of pigment that can appear as white patches on the skin. Vitiligo affects between 1 and 2% of people worldwide.
Albinism is a rare genetic condition that occurs when the body does not produce enough melanin. This can happen due to a reduced number of melanocytes or reduced melanin production. There are different types of albinism, but most cause a moderate to severe lack of pigment in the skin, hair, and eyes.
People with albinism generally have white hair, blue eyes, pale skin, and may have vision problems. There is no cure for albinism, but it is recommended to apply sunscreen products and avoid, as much as possible, exposure to ultraviolet rays to limit sun damage.
In conclusion, melanin is a substance produced by melanocytes and is responsible for skin pigmentation. Each person has a different amount of melanin in their skin. The level of melanocytes and the ratio of melanin forms in the skin dictate how much pigment is present. The amount of melanin is generally determined by genetics, but can be influenced by other factors such as sun exposure, hormonal changes, or age. In addition to being a pigment that gives color to skin, hair, and eyes, melanin also absorbs harmful ultraviolet rays and provides protection against cellular damage caused by UV light exposure.
Conținutul IvaStories este creat de echipa Ivatherm, brand romanesc de dermatocosmetice fondat de Dr. Rucsandra Hurezeanu. Produsele Ivatherm sunt formulate cu Apă Termală Herculane și sunt testate dermatologic, recomandate de medici specialiști.
Melanin: role, types and effects on the skin
Melanin is a term used to describe a large group of molecules responsible for many biological functions, including skin and hair pigmentation, as well as photoprotection of the skin and eyes. Thus, melanin plays an important role in determining hair, skin, and eye color. Genes, inherited from parents, largely dictate the amount of melanin. The greater the amount of melanin, the darker the eyes, hair, and skin will be.
In this article, we explain what melanin is, its main types, and how it influences skin health. We also present the benefits of this pigment and the conditions that can arise when melanin levels are imbalanced.
Table of Contents
What is melanin?
Melanin is a term that defines a group of natural pigments found in the human body. Melanocytes, the cells in the deepest layer of the epidermis (basal layer), and hair follicles produce melanin. This pigment gives color to the skin, hair, nose, inner ear, and choroid (the vascular and pigmented membrane of the eye, located between the sclera and retina).
Natural melanin levels are primarily determined by genetic factors. However, other causes can influence melanin production, such as:
Melanocytes house melanin in intracellular vesicles called melanosomes. The level of melanin in the skin is a result of the amount and distribution of melanocytes.
Melanocytes produce melanin in the basal layer, which is the deepest layer of the epidermis. Keratinocytes then transport melanin to the skin's surface.
Everyone has the same number of melanocytes, but some people produce more melanin than others. If cells produce only a little melanin, hair, skin, and eye irises can be very light. If cells produce more pigment, then hair, skin, and eyes will have a darker shade.
However, people with dark skin have melanosomes that are greater in number, larger in size, and more pigmented than those with light skin. This is why there are so many skin colors.
It is possible for a person to produce too much melanin in the body. This process is called hyperpigmentation and can occur due to certain conditions or an excess presence of a melanocyte-stimulating hormone.
Factors that can increase the amount of melanin in the skin include:
Sometimes, a person can have too little melanin in the skin, which is called hypopigmentation. Two examples of hypopigmentation are vitiligo and albinism.
Types of melanin
Although melanin is usually referred to as a single pigment, there are actually several types of melanin:
Eumelanin and pheomelanin are produced in different amounts in the basal layer of the epidermis, in cells called melanocytes. In contrast, neuromelanin is found in the brain.
While eumelanin and pheomelanin control the colors of visible parts (such as skin, hair, and eyes), neuromelanin is responsible for the color of neurons.
Differences in skin pigmentation are due to the ratio of eumelanin to pheomelanin, as well as the number of melanocytes.
Eumelanin can be divided into several types of black and brown. Eumelanin levels influence hair and skin color. For example, a high level of black or brown eumelanin results in a dark hair color, while small amounts are characteristic of blonde hair.
Therefore:
On the other hand, neuromelanin can give a dark color to parts of the brain. Research suggests that the presence of this pigment can help prevent cell death in certain parts of the brain. The loss of neuromelanin has been associated with symptoms of Parkinson's disease.
When we spend time in the sun, the body produces more melanin. The substance absorbs light from UV rays and redistributes it to the upper layers of the skin. It also protects the genetic material stored in cells by blocking access to harmful ultraviolet rays.
However, melanin alone is not enough to provide skin protection against the sun. Therefore, it is recommended to apply sunscreen products every day, regardless of the season.
Melanin: benefits
Melanin is not only responsible for skin, hair, and eye pigmentation, but also offers protection to the body.
Protection against UV rays. Melanin helps protect epidermal cells (the outer layer of the skin) from ultraviolet light and blue light. This happens by absorbing UV light before it can damage the sensitive DNA of skin cells.
Thus, melanin is an agent that absorbs ultraviolet rays and is capable of protecting the skin against the effects of UV light on the skin's surface. Eumelanin protects the skin from UV light, while pheomelanin does not. As a result, people with more pheomelanin, such as those with blonde or red hair and fair skin, are more susceptible to sun damage.
Protection against reactive oxygen species. Melanin also has protective effects against reactive oxygen species, the so-called free radicals. These are by-products of cellular processes in the body. When there is an accumulation of reactive oxygen species in cells, they can cause stress, premature aging, and health problems such as diabetes and cancer. Melanin neutralizes reactive oxygen species by stimulating antioxidants and eliminating free radicals.
Without the intervention of protective compounds, such as antioxidants, these reactive oxygen species contribute to oxidative stress, which causes significant cellular damage.
There are indications that there may be other mechanisms of melanin's action in the body, such as the protection of the liver, intestines, and even the immune system. However, research on these potential actions is limited, so pigmentation and photoprotection remain the two main benefits of melanin.
Conditions associated with melanin
Generally, genetics determine the amount of melanin in hair, skin, and eyes, but there are two conditions people can suffer from if they don't have enough melanin.
Vitiligo is an autoimmune condition that occurs when the body does not have enough melanocytes. This causes a lack of pigment that can appear as white patches on the skin. Vitiligo affects between 1 and 2% of people worldwide.
Albinism is a rare genetic condition that occurs when the body does not produce enough melanin. This can happen due to a reduced number of melanocytes or reduced melanin production. There are different types of albinism, but most cause a moderate to severe lack of pigment in the skin, hair, and eyes.
People with albinism generally have white hair, blue eyes, pale skin, and may have vision problems. There is no cure for albinism, but it is recommended to apply sunscreen products and avoid, as much as possible, exposure to ultraviolet rays to limit sun damage.
In conclusion, melanin is a substance produced by melanocytes and is responsible for skin pigmentation. Each person has a different amount of melanin in their skin. The level of melanocytes and the ratio of melanin forms in the skin dictate how much pigment is present. The amount of melanin is generally determined by genetics, but can be influenced by other factors such as sun exposure, hormonal changes, or age. In addition to being a pigment that gives color to skin, hair, and eyes, melanin also absorbs harmful ultraviolet rays and provides protection against cellular damage caused by UV light exposure.
Resources:
https://my.clevelandclinic.org/health/body/22615-melanin
https://www.webmd.com/a-to-z-guides/what-is-melanin
https://www.healthline.com/health/skin/benefits-of-melanin#bottom-line
https://www.ncbi.nlm.nih.gov/books/NBK459156/
https://ro.co/health-guide/what-is-melanin/
https://www.sciencedirect.com/topics/neuroscience/melanin
Echipa Ivatherm
Conținutul IvaStories este creat de echipa Ivatherm, brand romanesc de dermatocosmetice fondat de Dr. Rucsandra Hurezeanu. Produsele Ivatherm sunt formulate cu Apă Termală Herculane și sunt testate dermatologic, recomandate de medici specialiști.