The Importance of Melanin

asavannah's picture
      Skin is the body’s largest organ and is very essential for our survival; it is what protects all our other organs from antigens that are detrimental to our health. The book Skin: A Natural History by Dr. Nina Jablonski is a very informative chronicle on how our skin protects us and at the same time allows the world to see one’s state of health, identity, and uniqueness.
       Dr. Jablonski explains a wide range of topics relative to the skin such as its structure and function, how different variations of skin color came into existence, how skin reflects emotion, and various other subjects. One topic that I was particularly intrigued by was the chapter on skin’s dark secret. In this chapter she focuses on melanin that is found in our skin.  She then touches on albinism which is a disease that I have been very interested in learning more about and was able to do so through the information uncovered in this book.  
      First, it is necessary to explain the importance of melanin in our bodies. It is our skin’s very own sunscreen which protects it from harmful Ultraviolet rays (UVR) from the sun. Melanin is .responsible for the various pigmentations found in our skin. As stated by Dr. Jablonski, “Homo sapiens, skin colors make up an exquisite palette, varying in almost imperceptible degrees from the palest ivories to the darkest browns.” (65). The reason for different degrees of color is due to the amount of melanin pigment that an individual’s skin contains. 
      Dr. Jablonski explains that melanin is the name given to a group of complex polymeric pigments which exist in an array of different forms. In human skin, melanin is composed of a mixture of compounds which include melanin polymers, building blocks, and products used for breaking down substances. These molecules work together to absorb all the wavelengths from the UVR rays that are damaging to the skin.
     Melanocytes are what produce melanin; they are located in the stratum basale, the bottom layer, of the skin’s epidermis and also in the middle layer of the eye. Melanin pigment is produced by the melanocytes in small packets called melanosomes. The melanosomes are then forced out of the melanocytes and then taken into the keratinocytes in the epidermis. The size and shape of the melanosomes has a lot to do with their ability to protect the skin from UVR. The melanosomes are larger, contain lots of melanin, and are distributed evenly within the karatinocytes in darkly pigmented skin which allows for more absorption of energy than what would be found in lightly pigmented skin.
     Many different factors contribute to melanin being produced in the body; this includes pigmentation genes, hormones, and UVR. When there is an imbalance between and individual’s genes and hormones, the production of melanin in the body can be disturbed partly or wholly. When this happens, it causes an individual to have little or no pigment in their hair, skin, and eyes; this is called albinism.
     Albinism can exist in all animals, which include birds, fish, insects, other invertebrates, and mammals. Jablonski states that, “albinism is the normal condition for many species of fish and invertebrates that live in caves or at great depths in the oceans where solar radiation cannot penetrate.”(69). Strong pressures from natural selection to maintain the production of melanin in the body for protection has been lost due to the habitat in which these species live because it is not necessary for survival.
     Several types of albinism exist, in humans there are two different forms of the condition. One condition is called ocular albinism and the other is oculocutaneous albinism. Ocular albinism is the loss of melanin production in the eyes only and oculocutaneous albinism occurs when the production of melanin is not allowed to form through out the body, this causes the lack of pigmentation in the eyes, skin, and hair.
    People with albinism have difficulties with their vision and are also more susceptible to getting skin cancer if they do no properly protect their skin while in the sun.  There are also several misconceptions of people with this disorder. A common mistake people make about those with this disorder is that they are sterile which is definitely not true because they are fully capable of reproducing. Another fallacy of albinistic people is that they have a short life span. This may be confused with the idea that they are more likely to get skin cancer but with proper care of the skin in the sun, this problem may no longer exist.
    In different parts of the world, people with albinism not only suffer from health problems but also from social challenges. They may be ridiculed or discriminated against. Also in some cultures, it is often believed that they contain some sort of magical powers, for example in Zimbabwe; there is a myth that having sexual intercourse with someone with albinism will cure a person who is infected with the HIV disease.
   Dr. Jablonski’s book allowed me to learn a significant amount of information about albinism.  Her research not only provided facts about the disease, but it offered a clear explanation as to what causes the disease, misconceptions about people who have the disease, as well as,  its connection to the melanin in our skin.   


Works Cited
Jablonsky, Nina. Skin: A Natural History. Berkeley, CA: University of California Press, 2006.

Comments

Louisa Oketah's picture

biology

your article is educating but i still have a confusion. How is sun a factor in melanin formation? Thanks

Anonymous's picture

medicinal findings

are there melanin producing drugs that can help the pigment develop some colour and protection from the sun?

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