Mineral Balancing

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Hair Colour and its Trace Element Content

John Bumpus

Hair colour is suspected to influence trace element concentrations in hair among various population subgroups. The amount of melanin pigments in the hair cortex determines hair colour, with darker hair having more melanin than lighter (blond or white) hair. Red hair contains iron-rich siderin pigments (Flesch, 1970), and melanin biosynthesis requires copper as an enzyme cofactor for tyrosinase (Lerner, 1950). This suggests a possible connection between trace element content in hair, and its colour.

As far back as 1951 (Dutcher, 1951), higher iron content in red hair compared to blonde or black hair has been reported. No connection was found between copper concentrations and hair colour. Other studies (Schroeder, 1969) have shown that black hair in males had significantly higher magnesium concentration than brown, blonde, or red hair in males. For females, red hair had higher magnesium concentration than blonde hair. They also found that:

  • Blonde hair in both sexes had lower zinc than black, brown, white, or red hair.

  • In males, red hair had more nickel than brown hair.

  • In males, black hair had less cadmium but more lead than other hair colours.

  • Copper, and chromium showed no difference in relation to hair colour.

Studies (Eads, 1973) have shown no differences in copper content based on hair colour. However, it has been observed that zinc levels are higher in darker hair colours in both sexes, and thus the Zn/Cu ratio may be meaningful.

Hair zinc and copper concentrations based on hair colour in a sample of 150 Brazilian boys (Dorea, 1983). Their study was unique in that, in addition to visually categorising hair colour into four groups (blonde, light brown, dark brown, or black), they established a quantitative colour classification using spectrophotometric determination of melanin content. They concluded that "hair colour, divided into four melanin concentration ranges, does not impact zinc or copper concentration in head hair."

Other Elements

Arsenic - There were no significant variations found in As concentrations in hair samples of different colours (black, brown, blonde, and grey) in the limited tests performed.

Cadmium - No clear relationship was identified between Cd levels and hair colour (Eads, 1973). Grey hair in females contained less Cd compared to natural-coloured female hair or grey-haired males. Younger female hair had higher Cd levels compared to older women. In males, black hair had lower Cd compared to other hair colours (Schroeder 1969).

Chromium - No clear relationship was found in large populations (Schroeder 1971).

Cobalt - Comparisons of single samples were done between red, black, and white hair from different ages and sexes (Schroeder 1967, 1969).

Copper - Higher levels of Cu have been reported in pigmented hair than white colour (Kikkawa, 1958). In a study comparing 22 males and females, it was found that black hair had slightly higher levels of copper (Cu) compared to brown, blonde, grey, and white hair (Anke, 1962). Another study (Schroeder 1969) found that female with grey hair had significantly lower levels of Cu compared to those with natural coloured hair, but this wasn't observed in males, suggesting it may not be related to greying.

Lead - It appears that Pb levels do not significantly contribute to hair colour (Eads, 1973). A study showed that female with grey hair had lower levels of lead (Pb) compared to those with pigmented hair, but this difference wasn't found in males (Schroeder 1969).

Mercury - No correlation between hair colour and mercury (Hg) levels was found (Eads, 1973).

Nickel - No differences were found in Ni levels in relation to hair colour by some researchers (Eads, 1973). Another study found that natural coloured hair of females had higher levels of nickel (Ni) than that of males, and red hair had higher levels of Ni compared to brown (Schroeder, 1969).

Selenium - A comparison of selenium (Se) levels in brown, red, grey, black, and white hair revealed no significant differences in the limited number of samples tested (Schroeder 1970).

Summary

Hair colour and trace element concentrations in hair can be compared to the icing and filling of a cake. Just as the colour of the icing on a cake does not determine the flavour of the filling, hair colour does not necessarily determine the trace element concentration in hair. Some trace elements, such as zinc, may be more closely related to hair colour, similar to how certain fillings may complement specific icing flavours. However, the relationship between other trace elements and hair colour is not yet clear, similar to how the flavour of a cake filling may not always match its icing.

It is interesting that tissue copper levels do not seem to be related with hair colour in either sex. Although copper is involved in the synthesis of melanin, there appears to be some agreement that the hair colour is independent of the concentration of this element in the hair. On the other hand, the zinc content of hair does appear to vary with hair colour. In the case of other trace elements, the situation is not at all clear. More information is needed on this aspect of hair trace element levels.

References

  • Anke, H. and H. J. Schneider. 1962. Mineral Stoffgehalt der Frauen und Mannerhaare . Deutsch Z Verdau Stoffnechaclkr 22 : 31-35

  • DUTCHER, T. F., & ROTHMAN, S. (1951). Iron, copper and ash content of human hair of different colors. The Journal of investigative dermatology, 17(2), 65-68. https://doi.org/10.1038/jid.1951.65

  • Dorea, J. G., & Pereira, S. E. (1983). The influence of hair color on the concentration of zinc and copper in boys' hair. The Journal of nutrition, 113(11), 2375-2381. https://doi.org/10.1093/jn/113.11.2375

  • Eads, E. A., & Lambdin, C. E. (1973). A survey of trace metals in human hair. Environmental research, 6(3), 247-252. https://doi.org/10.1016/0013-9351(73)90037-6.

  • Flesch P. (1970). Studies of the red pigmentary system. Archives of dermatology, 101(4), 475-482.

  • Kikkawa, H., Z. Ogita, K. Abe and K. Doi. (1958). Further Studies on the Relation between Metals and Natural Pigments. Science. 128:1431. https://doi.org/10.1126/science.128.3336.1431.a

  • LERNER, A. B., & FITZPATRICK, T. B. (1950). Biochemistry of melanin formation. Physiological reviews, 30(1), 91-126. https://doi.org/10.1152/physrev.1950.30.1.91

  • Schroeder, H. A., Balassa, J. J., & Tipton, I. H. (1963). ABNORMAL TRACE METALS IN MAN--VANADIUM. Journal of chronic diseases, 16, 1047-1071. https://doi.org/10.1016/0021-9681(63)90041-9

  • Schroeder, H. A., & Balassa, J. J. (1966). Abnormal trace metals in man: arsenic. Journal of chronic diseases, 19(1), 85-106. https://doi.org/10.1016/0021-9681(66)90152-4

  • Schroeder, H. A., Nason, A. P., & Tipton, I. H. (1967). Essential trace metals in man: cobalt. Journal of chronic diseases, 20(11), 869-890. https://doi.org/10.1016/0021-9681(67)90024-0

  • Schroeder, H. A., & Nason, A. P. (1969). Trace metals in human hair. The Journal of investigative dermatology, 53(1), 71-78.

  • Schroeder, H. A., Frost, D. V., & Balassa, J. J. (1970). Essential trace metals in man: selenium. Journal of chronic diseases, 23(4), 227-243. https://doi.org/10.1016/0021-9681(70)90003-2

  • Schroeder, H. A., Balassa, J. J., & Tipton, I. H. (1970). ESSENTIAL TRACE METALS IN MAN: MOLYBDENUM. Journal of chronic diseases, 23(7), 481-499. https://doi.org/10.1016/0021-9681(70)90056-1

  • Schroeder, H. A., & Nason, A. P. (1971). Trace-element analysis in clinical chemistry. Clinical chemistry, 17(6), 461-474.