The purpose of the study was to evaluate the hair growth characteristic of individuals born in Africa. Here were the results:
Hair density varied from 90 to 290 hairs cm-2, with higher counts on the vertex. No significant difference between men and women was recorded. Telogen percentage showed wide variations, from 2 to 46%, with higher levels on the temporal area and in men. The rate of growth fluctuated from 150 to 363 µ.m day-1 with no difference related either to gender or to scalp region. These data were compared with those previously obtained in Caucasian volunteers of comparable age, and showed significant differences between the two ethnic groups in all three parameters studied. Hair density in African volunteers was lower than that in caucasians (mean ^ SD 190 ^ 40 and 227 ^ 55 hairs cm-2, respectively). African hair grew at a much slower rate than caucasian hair (mean ^ SD 256 ^ 44 vs. 396 ^ 55 µ.m day-1), and telogen counts were frequently higher in African hair (mean ^ SD 18 ^ 9% vs. 14 ^ 11%).
A quick explanation of this as it relates to hair growth only
If you are wondering, µ.m means micro millimetres. So in essence the original hair growth rate range of 150-363 micro millimeteres calculated over the 365 days in a year would equate to a range of 54,750-132,495 micro millimeters a year. In other words it is 2.1-5.2 inches of hair growth in a year. That would make the average growth of the group recorded to be at 3.65 inches of hair in a year.
They concluded that:
This study demonstrated significant differences between African and Caucasian hair growth parameters, which might suggest a trend towards increased hair loss in Africans, even though it contrasts with a lower and slower incidence of the development of alopecia in Africans.
It’s also important to note that even though the individuals studied were born in Africa, they were actually living in Paris at the time of the study and were healthy and free of systemic or cutaneous disease. In this case malnutrition would have been unlikely to have been a major influence in the outcome.
Of course the rate of hair growth in 19 African individuals is unlikely to be considered the standard for all Africans or in fact, all people of African descent. More than anything, this study shows a glaring inadequacy in the range of data which is covered in the study of cosmetology today.
Hair growth rate notwithstanding, a lot of what is taught to cosmetologists is based largely on Caucasian hair which in and of itself could be a problem if the person studying it will be dealing mainly with black hair and as such many of the facts learned may have very little to do with our hair.