Skin pigments are those responsible for the coloration of human skin. The human skin can range from a wide variety of shades, which is due to the natural pigments contained in melanin, the complex ‘ink’ of the skin. The melanin pigment is synthesized by special cells called melanocytes, which are located in the lower layer (stratum basale) of the epidermis. The melanin pigment originates from a circulating precursor or a natural pigment. There have been several myths and mysteries surrounding the ‘foreign’ origins of skin pigment, with many people believing that they may have arisen from other sources like food, drink, medication or other environmental factors. However, while some research studies have indicated possible causes, we are yet to reach a conclusive verdict on their true origins.
The Different Types of Skin Pigments and Their Roles
The human skin comprises three primary types of pigments that provide coloration, namely melanin, carotene, and hemoglobin. Melanin is the most abundant natural pigment in humans and is responsible for the color of the skin, hair, and eyes. Hemoglobin is responsible for red and pink hues and is found in blood vessels. Carotene, a yellowish pigment, is found in yellow fruits and vegetables and is responsible for the yellow hues in the skin.
Melanin
Melanin, the most common pigment in the skin, originates from melanocyte cells located in the epidermis. The pigment cells produce melanin in two primary variations, namely eumelanin and pheomelanin. Eumelanin is responsible for dark-color shades, while pheomelanin is responsible for lighter shades.
Carotene and Hemoglobin
Carotene, the yellow pigment in the skin, originates from plant-based sources, and it is obtained through the diet. The yellow pigmentation that results from the metabolization of carotene-rich foods is mostly concentrated in the palms of the hand and the soles of the feet. Hemoglobin, on the other hand, is responsible for the pink or red hues of the skin.
The Mystery of Skin Pigment’s Foreign Origins
For many years, research studies have tried to investigate the possibility of foreign or unnatural causes of skin pigmentation. However, conclusive answers are yet to be found. For instance, it was initially believed that food containing carotene, like carrots, would affect the skin’s pigmentation. However, numerous studies later concluded that, while carotene-rich food could affect the hue of the skin, they had no role in pigmentation formation.
Some studies have investigated the possibility of mineral or chemical-based pigmentation, such as fluoride. Research has shown that exposure to fluoride may lead to fluorosis, a condition that causes discoloration of the skin. However, such situations have mostly been reported due to significant exposure to fluoride over a prolonged period. Therefore, while research studies continue on the possible sources of foreign pigmentation, we are yet to reach any conclusive verdict on their true origins.
What is Albinism?
Albinism is a rare genetic disorder that affects the melanin production in the body. The condition leads to little or no production of melanin, resulting in the loss of skin pigmentation, resulting in a ‘whiter’ appearance.
Factors Affecting Skin Pigmentation
Several factors may affect the pigmentation of the skin. These may include:
- Genetics
- Skin damage
- Hormonal changes
- Duration of sun exposure
- Age
Genetics
Genetics plays a significant role in determining the skin pigmentation of an individual. People with a family history of darker skin tones are more likely to have such collars compared to those with a history of lighter shades. Also, genetic disorders like albinism can affect melanin formation, resulting in pigmentation issues.
Skin Damage
Various forms of skin damage can also affect skin pigmentation. Excessive exposure to UV radiation from the sun, certain medical treatments like chemotherapy and radiation therapy, and skin infections can lead to loss of pigmentation.
Hormonal Changes
Hormonal changes can also affect the color of the skin. For example, pregnancy can cause changes in skin pigmentation due to the fluctuations in hormone levels, leading to the formation of melasma.
Duration of Sun Exposure
The duration of sun exposure can significantly affect the pigmentation of the skin. Prolonged exposure leads to the production of more melanin to protect the skin, thus resulting in a darker hue.
Age
As one ages, the production of melanin in the skin gradually decreases, leading to the appearance of lighter skin tones.
Conclusion
While melanin is the principal pigment responsible for skin color, research studies from different fields continue to speculate on the possible sources of foreign pigments in the skin. Factors such as genetics, sun exposure, hormonal changes, age, and skin damage significantly affect skin pigmentation. However, while we continue to search for the mystery of skin pigment’s foreign origins, we must appreciate the primary function of melanin in protecting the skin from excessive UV radiation.
Common Questions About Skin Pigmentation
- What is the primary pigment responsible for skin color?
- The primary pigment responsible for skin color is melanin.
- Can skin pigmentation change over time?
- Yes, skin pigmentation can change over time due to various factors like sun exposure and aging.
- What are the factors that determine skin pigmentation?
- The primary factors that determine skin pigmentation include genetics, sun exposure, hormonal changes, age, and skin damage, among others.
- What is albinism?
- Albinism is a genetic disorder that affects the production of melanin, resulting in little or no pigmentation in the skin.
- What role does carotene play in skin pigmentation?
- Carotene, a yellow pigment found in plant sources, does not affect skin pigmentation. However, it can cause yellow hues on certain parts of the skin, like the soles of the feet and the palms of the hand.
References
1. American Academy of Dermatology Association. (2018). What Causes Skin to Change Pigment? https://www.aad.org/public/everyday-care/injured-skin/burns/causes-change-color
2. Nagaraja, S., & Rangaswamy, J. (2017). Pigmentation of the Skin: An Overview. Journal of Natural Science, Biology, and Medicine, 8(1), 1–4. https://doi.org/10.4103/0976-9668.198347
3. Shim, M. S., Kim, H. S., & Lee, J. W. (2010). Melanin-based nanoparticles for highly efficient gene delivery. Journal of Controlled Release, 143(2), 206–213. https://doi.org/10.1016/j.jconrel.2009.12.003
4. Tamer, E., Ilhan, M. N., Polat, K. T., Caliskan, M., & Tamer, G. S. (2018). Relationship of Antioxidant Capacity Levels and Skin Diseases. Journal of Cosmetic and Laser Therapy, 20(7–8), 420–423. https://doi.org/10.1080/14764172.2018.1465076