NationMaster - Encyclopedia: Hair color

Hair color is the result of pigmentation due to the presence of the chemicals of melanin and phaeomelanin. Broadly, melanin is any of the polyacetylene, polyaniline, and polypyrrole blacks and browns or their mixed copolymers. ... Melanin is a polymer of either or both of two monomer molecules: indolequinone, and dihydroxyindole carboxylic acid. ...

Human beings have many variations in hair color and hair texture. In general, the more melanin present, the darker the hair color; less melanin, the lighter the hair color. Usually the color of children's and adults' hair varies from pale yellow (blonde) to deep black. Hair may also come in more than one shade of color on one's head. As an example, the shade of one's hair color may change from a light shade to a darker one as time elapses. Human beings are defined variously in biological, spiritual, and cultural terms, or in combinations thereof. ... It has been suggested that this article or section be merged into Hair. ...

The ethnic distribution of colors has historically varied by geographic area. For example, black hair predominates outside of Europe, with the darkest shades occurring in East Asians. Black, brown, blonde and red hair occur in Europeans with the lightest shades occurring in Northern Europe. East Asia is a subregion of Asia. ... World map showing the location of Europe. ... Northern Europe is marked in dark blue Northern Europe is a name of the northern part of the European continent. ...

Considerable differences in hair color and texture exist between individuals of similar ethnicity, and immigration and global travel have greatly increased the diversity of hair characteristics in many countries. People also dye their hair to colors that do not occur naturally. This article or section should be merged with ethnic group Ethnicity is the cultural characteristics that connect a particular group or groups of people to each other. ... This article or section is not written in the formal tone expected of an encyclopedia article. ...

Pigment

There are two types of pigment that gives hair its color, eumelanin and phaeomelanin. Eumelanin is black, and pheomelanin is red. All humans have pheomelanin in their hair. How dark it is depends on how much eumelanin is present. A low concentration of eumelanin in the hair will give blonde hair, more eumelanin will give it a brown color, and much higher amounts of eumelanin will result in black hair. Melanin is a polymer of either or both of two monomer molecules: indolequinone, and dihydroxyindole carboxylic acid. ... Melanin is a polymer of either or both of two monomer molecules: indolequinone, and dihydroxyindole carboxylic acid. ... Black cat, thought by some to cause bad luck (see superstition) Black is the shade of objects that do not reflect light in any part of the visible spectrum. ...

Pheomelanin is more chemically stable than eumelanin, so it breaks down more slowly when oxidized. It is for this reason that Egyptian mummies have reddish hair, as the pheomelanin is still present but the eumelanin has broken down. This is also the reason bleach will cause darker hair to turn red as it is processing, when it has broken down the eumelanin quickly but acts more slowly on the pheomelanin. As the pheomelanin breaks down, the hair will then become orange, then the chemicals turn it yellow. A mummy is a corpse whose skin and dried flesh have been preserved by either intentional or accidental exposure to chemicals, extreme cold, very low humidity, or airlessness. ... Commercial chlorine bleach To bleach something, is to remove or lighten its color, sometimes as a preliminary step in the process of dyeing; a bleach is a chemical that produces these effects, often via oxidation. ... The orange, a fruit from which the modern name of the orange colour comes. ...

Effects of aging on hair color

A change in hair color typically occurs naturally as people age, usually turning their hair from its natural color to grey, then to white. More than 40 percent of Americans have some grey hair by their fortieth birthday, but grey hairs can appear as early as the teens and twenties for some, or even in childhood. The determination of when someone begins greying, whether it comes with aging or prematurely, seems to be almost entirely based on genetics. Sometimes people are born with grey hair because it is passed down genetically. Many people use hair dye to disguise the amount of grey in their hair. Image File history File linksMetadata Size of this preview: 800 Ã— 600 pixelsFull resolution (2048 Ã— 1536 pixel, file size: 840 KB, MIME type: image/jpeg) facial skin in old age I, the creator of this work, hereby release it into the public domain. ... Image File history File linksMetadata Size of this preview: 800 Ã— 600 pixelsFull resolution (2048 Ã— 1536 pixel, file size: 840 KB, MIME type: image/jpeg) facial skin in old age I, the creator of this work, hereby release it into the public domain. ... DNA, the molecular basis for inheritance. ... Ashlie from Lizzie McGuire, with green hair Hair coloring products generally fall into four categories: temporary, semipermanent, deposit only/demi, and permanent. ...

The change in hair color is caused by the gradual decrease of pigmentation that occurs when melanin ceases to be produced in the hair root, and new hairs grow in without pigment. Two genes appear to be responsible for the process of greying, Bcl2 and Mitf. The stem cells at the base of hair follicles are responsible for producing melanocytes, the cells that produce and store pigment in hair and skin. The death of the melanocyte stem cells causes hair to begin going grey.^[1] In biology, pigment is any material resulting in color in plant or animal cells which is the result of selective absorption. ... Broadly, melanin is any of the polyacetylene, polyaniline, and polypyrrole blacks and browns or their mixed copolymers. ... For a non-technical introduction to the topic, see Introduction to Genetics. ... Mouse embryonic stem cells with fluorescent marker. ... This article or section does not cite its references or sources. ...

There are no special diets, nutritional supplements, vitamins, nor proteins that have been proven to slow, stop, or in any way affect the greying process, although many have been marketed over the years. This may change in the near future, however. French scientists treating leukemia patients with a new cancer drug noted an unexpected side effect: some of the patients' hair color was restored to their pre-grey color. [1]

A 1996 British Medical Journal study conducted by J.G. Mosley, MD found that tobacco smoking may cause premature greying. Smokers were found to be four times more likely to begin greying prematurely, compared to nonsmokers in the study.^[2] The British Medical Journal (BMJ) is a medical journal published weekly in the United Kingdom by the British Medical Association (BMA)which published its first issue in 1845. ... The cigarette is the most common method of smoking tobacco. ...

The color of the hair of mummies or buried people can change over large time periods. Hair contains a mixture of black-brown-yellow eumelanin and red phaeomelanin. Phaeomelanin is much more stable than eumelanin, so that the phaeomelanin in the hair is better preserved over time than the eumelanin. The color of hair changes faster under extreme conditions. It changes more slowly under dry oxidising conditions (such as in burials in sand or in ice) than under wet reducing conditions (such as burials in wood or plaster coffins).^[3] Mummified cat from Ancient Egypt. ... The most fundamental reactions in chemistry are the redox processes. ... For the musician, see Burial (musician). ...

Medical conditions affecting hair color

Albinism is a genetic abnormality where no pigment is found in human hair, eyes or skin, making the eyes grey, blue, or red and the hair pale white or blonde, and the skin pale white. Albinism (from Latin albus; extended etymology), more technically hypomelanism or hypomelanosis, is a form of hypopigmentary congenital disorder, characterized by a lack of melanin pigment in the eyes, skin and hair (or more rarely the eyes alone). ...

Vitiligo is a patchy loss of hair and skin colour that may occur as the result of an auto-immune disease. Vitiligo (IPA ) or leukodermia is a chronic skin condition that causes loss of pigment, resulting in irregular pale patches of skin. ... Autoimmune diseases arise from an overactive immune response of the body against substances and tissues normally present in the body. ...

Malnutrition is also known to cause hair to become lighter, thinner, and more brittle. Dark hair may thus turn reddish or blondish due to the decreased production of melanin. The condition is reversible with proper nutrition. Percentage of population affected by malnutrition by country, according to United Nations statistics. ...

Werner syndrome and pernicious anaemia can also cause premature greying. A recent study demonstrated that people 50-70 years of age with dark eyebrows but grey hair are significantly more likely to have type II diabetes than those with both grey eyebrows and grey hair.^[4] Werner syndrome is a very rare, autosomal recessive disorder; its most recognizable characteristic is premature aging. ... Pernicious anemia refers to a type of autoimmune anemia. ...

Grey hair may temporarily darken after inflammatory processes, after electron-beam-induced alopecia, and after some chemotherapy regimens. Much remains to be learned about the physiology of human greying.^[5]

Genetics

The genetics of hair colour are not yet firmly established. According to one popular theory, at least two gene pairs control human hair color. One gene, which is a brown/blonde pair, has a dominant brown allele and a recessive blonde allele. If a person carries the brown allele, they will have brown hair; otherwise, they will be blonde. This also explains why two brown-haired parents can produce a blonde-haired child. The other gene pair is a not-red/red pair, where the not-red allele (which suppresses production of phaeomelanin) is dominant and the allele for red hair is recessive. Since the two gene pairs both govern hair color, a person with two copies of the red-haired allele will have red hair, but it will be either auburn or bright reddish orange depending upon whether the first gene pair gives a brown or blonde hair color respectively. The recessive genes for both brown/blonde and red hair are found nearly exclusively in populations of white people. Melanin is a polymer of either or both of two monomer molecules: indolequinone, and dihydroxyindole carboxylic acid. ... The term white people (also whites or white race) has been defined as being a member of a group or race characterized by light pigmentation of the skin and to a human group having light-colored skin, especially of European ancestry. ...

However, the two-gene model cannot explain the various shades of brown, blonde, or red which may occur (for example, platinum blonde versus dark blonde/light brown), or why a blonde child's hair might turn brown as they grow up while another blonde child's hair does not. There are several gene pairs that control the light versus dark hair color in an accumulative effect. Therefore, the more of these that are dominant, the darker the hair will be.

The light hair distribution map shown here refers to light hair as being blonde and red, and dark as being black and brown.

Common hair colors

Natural hair color is generally blond, red, brown, or black depending on the ethnic origins of the person in question. Hair color is genetically associated with certain skin tones, eye colors, and disorders such as skin cancer or albinism in persons with blond or red hair. Black hair is the most common.^[6]

Black hair

Black hair is found in people of non-European heritage most commonly, but occurs in people of all backgrounds and ethnicities. It has large amounts of eumelanin and is less dense than other hair colors. It can be almost completely black or very deep black with different hair texture depending on the person and the ethnicity. For example most people of East Asian descent have straight black hair, while people of sub-Saharan African descent generally have thick, coarse hair. The many black-haired Caucasoids of the Mediterranean, Middle East, North Africa, South Asia, and the British Isles exhibit practically all hair forms but wooly. Image File history File links Black-Hair. ... Image File history File links Black-Hair. ... Man with black hair indian girl with black hair Black hair is the darkest and most common color of human hair. ... Melanin is a polymer of either or both of two monomer molecules: indolequinone, and dihydroxyindole carboxylic acid. ... It has been suggested that this article or section be merged into Hair. ...

Brown hair

Brown hair is also found all over the world. Brown hair has more eumelanin than blond hair but also has much less than black. Brown-haired people have medium-thick strands of hair. A brown-haired male is a brunet; a female is a brunette. Image File history File links Download high resolution version (1280x1707, 131 KB)Picture of a brunette on a dark background. ... Image File history File links Download high resolution version (1280x1707, 131 KB)Picture of a brunette on a dark background. ... A woman with brown hair Brown hair is characterised by very high levels of the dark pigment eumelanin and lower levels of the pale pigment phaeomelanin. ... Melanin is a polymer of either or both of two monomer molecules: indolequinone, and dihydroxyindole carboxylic acid. ...

Blond hair

Blond hair is a relatively rare human phenotype, occurring in approximately 2% of the world population with the majority of natural blondes being white. Naturally blond hair. ... Trinomial name Homo sapiens sapiens Linnaeus, 1758 Humans, or human beings, are bipedal primates belonging to the mammalian species Homo sapiens (Latin: wise man or knowing man) in the family Hominidae (the great apes). ... Individuals in the mollusk species Donax variabilis show diverse coloration and patterning in their phenotypes. ...

Blond hair ranges from nearly white (platinum blond, tow-haired) to a dark golden blonde. Strawberry blond is a rare type: a mixture of blond and red hair. Blondness is a recessive gene. Blond hair can have almost any proportions of phaeomelanin and eumelanin, but both only in small amounts. More phaeomelanin creates a more golden blonde color, and more eumelanin creates a "dishwater" or ash blonde. Natural blondes have the thinnest strand of hair. Image File history File links Download high-resolution version (1323x1250, 571 KB) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File links Download high-resolution version (1323x1250, 571 KB) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... A tow is an untwisted bundle of continuous filaments. ... It has been suggested that this article or section be merged into Dominance relationship. ... Melanin is a polymer of either or both of two monomer molecules: indolequinone, and dihydroxyindole carboxylic acid. ... Melanin is a polymer of either or both of two monomer molecules: indolequinone, and dihydroxyindole carboxylic acid. ...

Red hair

Red hair is the least common hair color. It ranges from vivid strawberry shades to deep auburn and burgundy. Female with red hair Male with red hair Red hair (also referred to as auburn, ginger, or titian) varies from a deep red through to bright copper. ...

Red hair is caused by a mutation of the Mc1r gene and is believed to be recessive.^[7] Red hair has the highest amounts of phaeomelanin and usually low levels of eumelanin. Natural redheads have the thickest strands of hair. The Melanocortin-1 receptor (Mc1r) is one of the key proteins in hair colour production. ... It has been suggested that this article or section be merged into Dominance relationship. ... Melanin is a polymer of either or both of two monomer molecules: indolequinone, and dihydroxyindole carboxylic acid. ... Melanin is a polymer of either or both of two monomer molecules: indolequinone, and dihydroxyindole carboxylic acid. ...

Hair color names

A woman with brown hair Brown hair is characterised by very high levels of the dark pigment eumelanin and lower levels of the pale pigment phaeomelanin. ... Mahogany is a brownish colour. ... Chocolate most commonly comes in dark, milk, and white varieties, with cocoa solids contributing to the brown coloration. ... Indian red also known as chestnut, is a brownish shade of red. ... Hu Jintao Keanu Reeves Elvis Presley dyed his hair jet black. ... Species See text. ... Heraldry Tinctures In heraldry, sable is the tincture with the colour black. ... Binomial name Diospyros ebenum Koenig ex Retz. ... Onyx is a banded variety of chalcedony, a cryptocrystalline form of quartz. ... Black cat, thought by some to cause bad luck (see superstition) Black is the shade of objects that do not reflect light in any part of the visible spectrum. ... Domino redirects here—for other meanings of the word, see Domino (disambiguation). ... Flax (also known as Light Goldenrod) is a pale yellowish-gray color named after Flax seeds. ... Naturally blond hair. ... A towhead is a sandbar or small alluvial island in a river that often features a small grouping of trees. ... One of the worlds most famous blondes Marilyn Monroe, who was in fact a natural brunette Blond (feminine, blonde) is a hair colour found in certain mammals characterised by low levels of the dark pigment eumelanin and higher levels of the pale pigment phæomelanin, in common with red... A jar of honey, shown with a wooden honey server and scones/biscuits. ... Gold is a shade of the color yellow closest to that of gold metal. ... Platinum Blonde may refer to: platinum blonde is a very light shade of hair colour, sometimes obtained by means of chemically bleaching out almost all natural colour from the hair. ... Woman with auburn hair. ... Indian red also known as chestnut, is a brownish shade of red. ... Female with red hair Male with red hair Red hair (also referred to as auburn, ginger, or titian) varies from a deep red through to bright copper. ... A forest fire Fire is a rapid oxidation process that creates light, heat, smoke, and releases energy in varying intensities. ... Russet is a brown color with a reddish tinge. ... Binomial name Cinnamomum verum J.Presl Cassia (Indonesian cinnamon) is also commonly called (and sometimes sold as) cinnamon. ... Silver is the metallic shade of the color gray closest to that of polished silver. ... Hair color is the result of pigmentation due to the presence of the chemicals of melanin and phaeomelanin. ... A modern uplighter lamp made completely from Italian alabaster (white and brown types). ... General Name, Symbol, Number platinum, Pt, 78 Chemical series transition metals Group, Period, Block 10, 6, d Appearance grayish white Standard atomic weight 195. ...

Contents

Pigment

Effects of aging on hair color

Medical conditions affecting hair color

Genetics

Common hair colors

Black hair

Brown hair

Blond hair

Red hair

Hair color names

See also

Footnotes

External links

Contents

Pigment GA_googleFillSlot("encyclopedia_square");

Effects of aging on hair color

Medical conditions affecting hair color

Genetics

Common hair colors

Black hair

Brown hair

Blond hair

Red hair

Hair color names

See also

Footnotes

External links

Pigment