Keratin and afro hair
Keratin and lipids in Afro hair

KERATINS, LIPIDS AND AFRO HAIR

Hair is mainly composed of mainly keratin, keratin associated proteins and lipids.  Afro, Caucasian and Asian hair demonstrate a large variation of hair textures. Though the texture of the hair fibres look entirely different, the keratin components of the hair shaft are almost identical [1].

When Afro hair was compared to other hair types, the main difference was the lipid content in the internal keratin structure of the hair fibre.  Healthy afro hair fibres contained 70% more lipids than Asian or Caucasian hair fibres.  It was found that the lipid content contributed to the strength and integrity of the hair fibre, and unlike Asian or Caucasian hair, without the fatty layer, the hair fibre would not maintain its native keratin structure [1].

THE FATIGUE MODEL FOR LIPIDS, KERATINS AND AFRO HAIR

It is common to read that African hair is weaker than other hair types, however, rarely mentioned is the relatively meagre magnitude of this difference.  Breakage comes with the force of working with afro hair fibres with a low internal lipid content. Daily grooming similarly constitutes the application of repeated, fatiguing stresses on individual hair strands, and this process is more arduous in compacted afro hair. In fact, Epps and Wolfram [2] reported African hair yielded dry state combing forces that were 10× higher than Caucasian hair; Syed [3] suggested a 50× difference.

MAINTAINING THE LIPID AND KERATIN CONTENT OF AFRO HAIR

A molecular simulation of the afro hair fibre showed that unlike other hair types, in afro hair lipids were interwoven into the microfibres that make up the hair shaft.  When these lipids were removed in all hair types, only Afro hair showed a difference in keratin structure.  The removal of lipids caused tighter packing of the hair keratin structure.  Effectively, the hair fibre shrunk [1].

This phenomenon, known as ‘shrinking’, occurs when the internal lipid content is too low for the keratin structure to retain its full uncoiled structure. When there are insufficient lipids, hydrogen bonds link excessively, this linkage would have been blocked by the hydrophobic nature of the lipid in the structure.

LIPIDS AND THE KERATIN WITHIN THE HAIR STRUCTURE

As afro hair needs to retain its lipid content to remain healthy, care must be taken to keep this content as high as possible throughout the life cycle of the hair fibre. When cleaning the hair use creamy cleansers with primary ingredients such as stearalkonium chloride or cetrimonium chloride.  These cationic surface cleansers are mild and leave hair easier to comb.  A high concentration of fatty alcohols such as cetyl-stearyl alcohol or a similar fatty material in addition to the cationic surfactant.

HOW TO INCREASE THE FATTY ACID CONTENT OF AFRO HAIR

The sebaceous gland at the base of each hair follicle is responsible the lipid content of the hair along with scalp microflora who also aid with the addition of fatty enzymes.  Estrogen receptor α is a sebaceous gland receptor that can be stimulated by phytoestrogen therapy to encourage growth of thicker hair.

Adding a cysteine precursor such as sulphur (MSM) to your supplement regime will contribute to a stronger keratin structure within the hair fibre with a higher lipid capacity.  Zinc is also shown to increase the size of sebaceous glands and regulate sebum production.  Tie hair in a silk headscarf at night to prevent lipid removal by friction and avoid products that are designed to reduce the oil content of the hair (such as dry shampoo).

REFERENCES

  1. Martí, M., Barba, C., Manich, A.M., Rubio, L., Alonso, C. and Coderch, L., 2016. The influence of hair lipids in ethnic hair properties. International journal of cosmetic science, 38(1), pp.77-84.
  2. Epps, J. and Wolfram, L.J. (1983). Letter to the editor. JCosmet. Sci, 34 213-214.
  3. Syed, A.N., Kuhajda, A., Ayoub, H. and Frank, E.M. (1995). African american hair Cosmet & Toilet 110 39-48.

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