Melanin and UV protection

Melanins are a group of pigments that give rise to the color in our skin, in our hair and in our eyes. While melanins have several functions in our bodies, probably the most important function is to protect our skin from the harmful effects of sunlight.

There are two basic classes of melanins:

Pheomelanin is a melanin that is found in smaller amounts in skin and hair. Light-skinned people have more pheomelanin than dark-skinned people. Pheomelanin contains the amino acid cysteine ​​which gives red/yellow color tones, and pheoalanine is very abundant in large quantities in red hair and also contributes to the reddish color of freckles.

Eumelanin is the most common melanin in human skin and hair, and dark-skinned people have more eumelanin. Eumelanin colors hair from brown to black, and eumelanin is also the form of melanin that is usually missing in albinism.

All melanins are produced by melanocytes, which are a type of cell in our outermost skin layer (epidermis). Specifically, the melanocytes are located at the bottom of the epidermis and they generate melanin inside membrane-bound structures called melanosomes. Melanocytes transfer melanosomes to the cells above, i.e. to the keratinocytes, these keratinocytes are the dominant cell type in our outermost skin layer.

Why is melanin so important?

Melanin's essential function is to protect our skin from harmful UV rays from sunlight. UV exposure is the biggest cause of skin cancer.

What is the difference between UVA and UVB rays?

You've probably heard of UVA and UVB rays, but here's a quick reminder of how different they are. UVA rays are the longer wavelength rays and represent the majority of UV radiation that reaches the atmosphere. UVB rays have shorter wavelengths and make up only a minority of UV radiation.

As the ozone layer is getting thinner, more and more UVB rays reach us, which is worrying considering that UVB rays are the most harmful and mutagenic (can cause mutations). UVA rays are also harmful to our genes, and UVA rays reach us even when we are sitting in the shade. The UVA rays penetrate deeper into the skin than the UVB rays do, and can have mutagenic effects in the dermis, i.e. the second layer of our skin that lies below the epidermis (the outermost skin layer).

Can UVA and UVB rays cause mutations in our DNA?

Both UVA and UVB rays can cause genetic mutations in our DNA. Fortunately, we have proteins to detect and repair DNA mutations. If a mutation is not detected and repaired, the mutation multiplies as the cell divides. And if the mutation is in certain genes, it can lead to cancer.

In the two most common types of skin cancer, mutations associated with UVB damage are found in over 50% of patients.

How does melanin protect against UV rays and skin cancer?

Melanin protects our skin from light in several ways. It absorbs and redistributes the light energy from the UV rays, and it protects our genetic material (DNA) stored in the cell nucleus from the rays.

How are skin color, melanin and skin cancer connected?

Light-skinned people are about 70 times more likely to develop skin cancer than dark-skinned individuals, suggesting that pigmentation is a key factor in skin cancer. The difference is not in the number of melanin-producing melanocytes, but in the amount of melanin produced. Asian individuals have, on average, twice as much melanin as Caucasians, while Africans have about three to six times more melanin. Since the rate of skin cancer in light-skinned and dark-skinned people differs by a factor of 70, factors other than the amount of melanin are clearly contributing factors.

Another contributing factor may have to do with the lifespan of the melanosome. One study showed that melanosomes in dark-skinned people are more resistant to cell breakdown (when cells become too unstable in an organism, resulting in its eventual death) than in light-skinned individuals.

Is melanin a good sun protection factor?

Melanin, as sun protection has an SPF or sun protection factor. Scientists debate exactly how much SPF melanin has, but it's around SPF 1.5 - 2 and can be as high as 4. That might not sound like much, but an SPF 2 represents doubling the amount of protection from the sun. If you think about it another way, melanin absorbs around half of the UV light we are exposed to.

How does UV light affect skin pigmentation?

After DNA damage or repair from UV light exposure, the production of melanin is increased and this creates a tanned skin. How skin pigmentation is regulated is not well understood but will likely be the subject of future research. In mammals, more than 120 genes are known to have a role in pigmentation.

In other words; when the skin is exposed to the sun's UVB radiation, it gradually forms a pigment - melanin - which protects against mainly UVB radiation, and causes the skin to tan. This production of melanin is called melanogenesis. The increased production of melanin is a reaction to the DNA damage caused by UV radiation. Melanogenesis leads to delayed tanning, which typically becomes visible two or three days after exposure.

UVA radiation does not cause sunburn, but reaches deeper into the skin and can break down the connective tissue protein collagen , which among other things accelerates skin aging, and makes the skin wrinkled and inelastic.

Can you increase the body's melanin?

People with any skin type can increase melanin to reduce the risk of skin cancer. Studies suggest that increased intake of certain nutrients can increase melanin levels.

Which nutrients in food can increase the body's melanin?

There are many nutrients that are believed to increase melanin and can improve the health of the skin in general, which can reduce the overall risk of developing skin cancer.

Different ways to increase melanin in the body

Nutrients may be the key to increasing melanin naturally in the skin. Here are some nutrients that can help your body produce more melanin.

Antioxidants

Antioxidants show the strongest potential for increased melanin production. Although more studies are needed, some research suggests that antioxidants may help.

Micronutrients such as flavonoids or polyphenols, which come from the plants we eat, act as powerful antioxidants and can affect melanin production. Some of them increase melanin , while others can help reduce it.

Eat more antioxidant-rich foods such as dark leafy greens, dark berries, dark chocolate and colorful vegetables to get more antioxidants. Taking a vitamin and mineral supplement may also help.

Vitamin A (retinol)

Studies indicate that vitamin A is important for melanin production and is important for healthy skin. You get vitamin A from the foods you eat, especially vegetables that contain beta-carotene, such as carrots, sweet potatoes, spinach and peas.

Since vitamin A also acts as an antioxidant, some researchers believe that this vitamin, more than any other, may be a key to melanin production. However, more studies are still needed to directly prove that vitamin A increases melanin in humans.

However, some studies suggest that taking vitamin A (specifically retinol) can be good for skin health.

A type of carotenoid (the substance that gives red, yellow and orange vegetables their color) is found in vitamin A. It may also play a role in melanin production and UV protection, according to research.

Vitamin A is found in animal products in the form of retinol, but also in certain plants as a precursor to vitamin A in the form of beta-carotene. You can increase vitamin A levels by eating more foods rich in vitamin A, such as oranges, vegetables (carrots, squash and sweet potatoes), fish and meat. Because vitamin A is a fat-soluble vitamin, it can build up in the body. If you want to take extra vitamin A from food supplements, make sure that the food supplement contains beta-carotene. Beta-carotene is only converted to vitamin A when needed, in the body.

Vitamin E (tocopherol/tocotrienol)

Vitamin E is an important vitamin for skin health. It is also an antioxidant and can possibly increase melanin levels.

Although there are no studies that prove a direct link between vitamin E and more melanin , some studies show that vitamin E can help protect the skin from sun damage.

You can get more vitamin E by taking a vitamin E supplement, or by eating more vitamin E-rich foods such as seeds and vegetable oils, margarine, wheat germ, green leafy vegetables, avocados, whole grains, and eggs.

Vitamin C (ascorbic acid)

Like vitamin A and vitamin E, vitamin C is also an antioxidant. Vitamin C is needed for healthy mucous membranes. Vitamin C can also have some effect on melanin production and also protects the skin.

There are no studies proving that vitamin C increases melanin production. However, anecdotal evidence suggests that vitamin C may increase melanin levels.

Eating vitamin C-rich foods such as citrus, berries and leafy greens can optimize melanin production. Taking a vitamin C supplement may also help.

Herbs and plants

Some studies have investigated the potential benefits of herbs and teas in protecting the skin from damage caused by UV rays. Herbal products such as green tea and turmeric, which are rich in flavonoids and polyphenols, can increase melanin levels in the body, and can help protect the skin.

So far, however, no studies have shown that herbs or plants of any kind can increase melanin production. At the moment, such claims are only anecdotal.

Eating healthy foods and taking supplements that contain certain vitamins and antioxidants, such as vitamins A, C, and E, can help you take care of your skin and may reduce your risk of skin cancer, according to some studies.

However, it has not yet been proven that these antioxidants reliably increase the body's melanin . The only proven way to prevent skin cancer is to stay out of excessive sunlight and use a high-quality sunscreen.