Is Pheomelanin Better Than Eumelanin?

Overview

Discussions about skin colour can cause discrimination to arise against individuals who have a certain skin colour. So, we need to ask ourselves if human skin colour matters that much. Is colourism relevant and a reason to devalue a person because they are not what you expect them to be? 

Pheomelanin and eumelanin are types of melanin. Melanin imparts pigmentation all over the body.  Therefore, every human possesses melanin that defines the colour of their hair, eyes and skin tone. 

Melanin is secreted by melanocytes, cells that are specialised to synthesise melanin. Melanocytes can be found all over the body. For instance, these cells can populate regions near the hair, the iris, and the adrenal glands. 

Melanocyte production is contained within organelles in the melanocytes, which are known as melanosomes. For pigmentation to occur, melanin from melanosomes needs to migrate to keratinocytes, cells that are abundant in the skin. Melanin can protect against irritants, such as ultraviolet (UV) radiation.¹

What is pheomelanin?

Pheomelanin is one of the types of melanin that causes skin to appear as a lighter colour tone. 

The accumulation of pheomelanin can cause a yellow and red pigment to appear, which is most pronounced on the lips, nipples, vagina and penis. Pheomelanin is also responsible for making hair appear blonde or red. Pheomelanin content is associated with lighter skin tone.¹

A high pheomelanin content is typical in people who live far from the equator zone, such as northern Europe. Pheomelanin can stimulate free radicals that are harmful to cells when exposed to UV rays. Unlike eumelanin, pheomelanin does not effectively protect from the harmful effects of UV. Exposure to UV light can progress into carcinogenesis, a form of deadly skin cancer called melanoma. 

What is eumelanin?

Eumelanin is another form of melanin. Eumelanin is stimulated in the basal layer of the epidermis. Eumelanin promotes darker skin pigmentation, giving black and brown pigmentation. Eumelanin’s melanocytes migrate more rapidly towards keratinocytes than pheomelanin’s melanocytes.¹ 

Populations living near the equator zone are more likely to be exposed to UV radiation. Eumelanin is a dark skin pigment that is abundant in people who are resident in hot countries.  

What are the similarities and differences between pheomelanin and eumelanin?

At a cellular level, eumelanin and pheomelanin are stimulated in the basal layer of the epidermis. Melanin synthesis begins in the same way, starting from an amino acid Tyrosine. Tyrosine is converted into dihydroxyphenylalanine by a tyrosinase enzyme and then follows another pathway where eumelanin and pheomelanin is produced.¹ 

People with red hair can also have both eumelanin and pheomelanin. Melanocytes possess a protein called the MC1R gene. The MC1R gene induces pheomelanin, which causes red hair. The MC1R gene is a recessive gene, which means it can easily be influenced by dominant traits, like eumelanin production.² 

In darker skin colour, the melanocytes contain an excessive amount of melanosomes compared to the skin cells that give a lighter skin tone. Additionally, people with eumelanin require a higher exposure to UV light in order to produce vitamin D effectively, more so than individuals who have lighter skin. Hence, people with eumelanin are more likely to develop a vitamin D deficiency than people with pheomelanin. 

Summary

Melanin is a biological component that causes skin, hair and eye pigmentation. Eumelanin and pheomelanin are two types of melanin that cause different pigmentation. Eumelanin is responsible for darker pigmentation, while pheomelanin causes lighter pigmentation, as well as the appearance of red hair. Both types of melanin confer protection against ultraviolet radiation, with eumelanin making skin more resistant to damage from sun rays. Although a person’s skin colour can be a point of discussion and can cause discrimination, it is more powerful to understand the biological function of skin colour.