Introduction:
After fertilization, the zygote (a cell that starts forming a baby) acquires 46 chromosomes, 23 from each parent. All the genetic traits such as hair color, eye color, and sex of the baby are determined at this stage. Specialized cells called melanocytes located at the base of each hair strand produce melanin. The presence of more melanin imparts dark color, while less melanin imparts blond color to the hair.
What Are the Different Pigments Present in the Hair?
There are two types of pigments that determine different shades of hair color, namely:
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Eumelanin: This pigment is responsible for brown or black hair color.
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Pheomelanin: This pigment is responsible for red hair color.
Hair Color Based On Type Of Melanin:
Black color hair is due to a large amount of eumelanin. Brown hair is because of moderate amount of eumelanin and one acquires blond hair due to very little amount of eumelanin. Red hair is due to the predominant presence of pheomelanin and a little amount of eumelanin.
Does the Baby’s Hair Color Change With Growth?
Babies have low levels of melanin at birth. After birth, with exposure to sunlight, the melanin level increases, causing a change in hair color. Melanin production decreases with age, so the hair turns gray or white as individuals age. A study by Forensic Science Communications shows that hair color in children between 9 months and 2.5 years of age is light. After three years, the hair color slowly progresses to a dark color till five years of age. The hair color shuffles between shades after birth before acquiring a permanent color.
What Are the Scientific Reasons for the Change in Hair Color?
Genes are responsible for giving instructions to cells. For example, the gene which determines hair color is called MC1R. The MC1R gene transfers information to form a protein called melanocortin 1 receptor, which is involved in melanin production. All the cells in our body have melanin-producing genes, but not all cells use these genes.
For example, the palms and the soles do not require melanin; hence the melanin-producing genes in these areas remain dormant. Melanin-making genes in the hair vary in activity over different periods, affecting hair color. It is these genes that control the levels of eumelanin and pheomelanin.
What Controls the Activity of Melanin-Producing Genes?
The chemical signals that are transmitted between various body parts are called hormones. These hormones influence hair color. Variations in different levels of these hormones can make the genes more or less active. Hormonal changes can occur even after puberty. In addition, certain factors like age, nutrition, temperature, exposure to the sun, and certain other factors can also affect hormonal levels.
What Are the Other Factors That Can Affect Hair Color?
Hair color can be affected by certain other factors:
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Chemicals: Chemicals such as bleach and chlorine can affect hair color. The main component of hair bleach is hydrogen peroxide, which reacts with the melanin pigments and turns them colorless. Hydrogen peroxide reacts more with eumelanin than with pheomelanin.
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Albinism: Albinism is a group of disorders in families characterized by little or no melanin production. Mutation or alteration of genes is responsible for albinism. Babies with albinism have little or no melanin in their eyes, skin, and hair. The hair color in these babies can be light, white, or in different shades. The eyelashes and eyebrows can be white. These kids are sensitive to sunlight and can have vision problems.
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Nutritional Deficiencies: A deficiency of vitamin B12 can cause premature graying of hair, even in kids. The National Institute of Health (NIH) considers vitamin B12 to be the powerhouse vitamin, and it helps prevent anemia.
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Vitiligo: Vitiligo occurs when the pigment-producing cells or melanocytes die or stop functioning. It is an autoimmune disease wherein the body’s immune system attacks its healthy tissues and causes visible white patches on the skin. This can affect the melanin in the hair, turning it gray. Vitiligo is difficult to treat in children. Treatment modalities include the use of corticosteroids, light therapy, and surgery.
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Mineral Deficiency: Premature graying in some children can occur due to a lack of certain minerals like zinc and copper.
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Folic Acid and Vitamin D: If kids do not get adequate exposure to sunlight, it can affect melanin production due to vitamin D deficiency. Folic acid and vitamin D deficiency can also contribute to hair color changes.
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Environmental Factors: Physical and emotional stress, exposure to UV (ultraviolet) rays, air pollution, and harsh shampoos can lead to colorless hair in teenagers.
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Poor Diet: Kids who frequently take junk foods or foods with nutrient imbalance tend to have lighter or prematurely gray hair.
What Happens to Melanin With Age?
With age, the cells producing melanin, called melanocytes, slow down in their activities. When a child enters adolescence or adulthood, hormonal levels can affect hair color. If adults or young individuals have hair fall, the melanocytes transfer the color to the new hair. Melanocytes can regenerate at a younger age even if they die, but in old age, they cannot regenerate and transfer the melanin to the new hair. If less melanin is transferred, it results in gray hair; if no melanin is transferred, it results in white hair.
Can a Baby's Hair Color Change From Dark to Light?
The three predominant hair colors include dark, blond, and red. However, a baby's hair color may change from dark to light due to genetic, hormonal, seasonal, and melanin levels.
How Does Genetics Play a Role in Hair Color?
A variant form of the same gene is called an allele. For example, if a child inherits two black alleles from its parents, the resulting hair color will be black. If both the inherited alleles are brown, the child's hair color will be brown. However, if one of the inherited alleles is brown and another blond, the resulting hair color will be that of the dominant color, that is, brown, because the less expressive or recessive hair color (blond in this case) will get suppressed.
Conclusion:
Statistics show that the rarest hair color is red and occurs in 2 percent of the population. Black and dark brown are the most common hair colors. Blond hair occurs in about 3 percent of the world's population, and brown, the second most common hair color, occurs in 11 percent of the total population. The baby's hair color is determined by genetics and can change with age. It takes some time for the child's hair color to become permanent.
