Properties of Tightly Coiled Afro-Textured  Hair

follicle types.jpg

Hair shaft/ follicle

  • Curved/ Curly hair and follicle in the scalp (1, 2, 3)

  • Hair shaft cross section is elliptical (Caucasians oval/ Asians round) (1, 2, 3, 4)

  • High degree of irregularity in the diameter along the hair shaft, with frequent twists and random reversals in direction with pronounced flattening (1, 5, 6, 7, 8, 9)

    • African hair tends to form knots

  • Microcracks and fractures in the hair fiber caused by natural constrictions along the twisted hair shaft leading to lower tensile strength and relative brittleness (2, 3, 10)

    • Made worse by everyday combing and grooming

    • Earlier breaking time under force

    • Lower stress requirements for breakage

  • Least amount of cuticle layers leading to a higher prevalence of hair breakage (5)

  • Fewer elastic fibers anchoring the hair follicles to the dermis in the black subjects, leading to increased susceptibility to traction alopecia (8, 9)

Oil producing glands (sebaceous glands) (5, 6, 8, 9):

  • Uneven distribution of sebum/ natural oils from root to tip, leading to dryer less shiny hair

  • More hair fiber oils BUT increased disruption of this oil barrier due to use use of damaging chemicals

Blood  supply: Lower blood flow to hair follicles, leading to increased prevalence of scarring alopecia (1, 8, 9)

Hair growth: Slower growth rate and less density (11)

References