Ethnicity and hair thickness

[Pondle]

A couple of posts on the GNXP blog that may be of interest...

http://www.gnxp.com/blog/2007/11/edar-c ... ckness.php
http://www.gnxp.com/blog/2007/11/hair-t ... update.php

 

[Armando Jose]

Thank you Pondle;

very interesting issue.

According to my theory people with thick and dense hair are more protected from common baldness, because hairs are touching among them and it is difficult to have problems with sebum flow. The lenght of hair is another important characteristic.

Regards

Armando

 

[Pondle]

Regrettably my very thick head of hair (in my teens and early 20s) didn't prevent the onset of male pattern baldness in my late 20s...

 

[Armando Jose]

Hi ponddle;

How about your hair density?

And your hair lenght?

Armando

 

[Pondle]

My hair was very dense in my childhood and teenage years, at least by visual comparison to my classmates and relatives. I had relatively long hair in my pre-school years, and shorter hair as a schoolboy, before wearing it long (collar or shoulder-length) in my late teens / early 20s.

Photos from my early 20s show the development of a mature hairline, which I didn't really notice at the time. By my mid-20s I was usually cutting my hair shorter, although never 'crew cut' short. At around age 27 I started to notice early thinning at the front and the crown, and an increase in the rate of shedding. I started on Propecia at 29, and saw a decrease in the rate of shedding within 2-3 months. I'm now 31, and have no further visible loss since starting treatment. For the last year I've started growing my hair longer, with my fringe reaching down to my eye level.

My cousin, who is a good comparator, seems to have had a consistently short hairstyle since childhood. He is a year older than me, and does not seem to have any hair loss. His father (my uncle) started thinning in his 30s/40s, maybe he will follow that pattern.

 

[docj077]

I've seen many, many people with long, thick hair suffer from both female and male pattern baldness. Density, length, and hair shaft diameter have nothing to do with the process. There are individuals on these very forums that can atest to the fact that the previously mentioned factors have no influence whatsoever on hair loss.

Armando, you could do a study here and now. Make a survey on these forums that asks the length of hair, the ethnicity, the thickness, etc. when the male pattern baldness process began and see what you get. Granted, the survey will be incredibly subjective, but you'll either prove a point or you won't.

 

[Bryan]

According to my theory people with thick and dense hair are more protected from common baldness, because hairs are touching among them and it is difficult to have problems with sebum flow. The lenght of hair is another important characteristic.

And yet Kligman and his colleagues showed conclusively that sebum has no propensity at all to be "absorbed" or "wicked-up" onto hairs and travel along their length. Your theory is based on a FALSE assumption, Armando. Why do you keep pushing a theory which has been soundly disproved?

 

[Bryan]

For those of you who aren't familiar with what I referred to in my previous post, here's the section from a study by the legendary Dr. Albert M. Kligman MD, PhD on the issue of how sebum gets onto human scalp hair in the first place (added emphasis is my own):

Refatting of Hair

Apart from the amount of sebum on the hair is the fascinating question of how it gets there. Hardly anyone has thought to look into the matter for the answer seems too obvious from the anatomy of the pilosebaceous unit. What could be more natural than to suppose that the sebum, excreted into the follicular canal, simply spreads up the hair shaft and uniformly coats it. Credit to Eberhardt for the imagination to question the obvious and for the elegantly simple methods employed in its refutation (Eberhardt 1976). When a droplet of sebum is placed on hair none of the lipid moves away; further, sebum will not creep along the surface when a terminal hair is placed in a capillary filled with sebum. We were incredulous and thought that the hair might first have to be moistened. However, we too found that sebum would not spontaneously spread out when droplets were placed on previously immersed hairs held in an atmosphere saturated with water. Further, we strung hairs in close parallel array on a wire frame, thinking that sebum placed at one end would migrate between the hairs by capillarity. Wetted or dry, the sebum showed not the slightest inclination to spread over the hairs as visualized by exposure to osmium tetroxide vapors. It seems an inescapable conclusion that the hairs become greased by mechanical transfer, from the scalp surface to the hairs, and from hair to hair. The hair acquires sebum by direct contact. The dispersal of sebum from the surface would be facilitated by combing and brushing, by wearing a hat, by rubbing the fingers through the hair, etc. Resilient, easily bendable thin hair would have a greater chance of contacting sebum than straight, stiff, widely-spaced hairs. Refatting of the hair is thus complex and will vary greatly from individual to individual.

So that would seem to completely contradict Armando's theory, because sebum doesn't naturally flow along the length of hair, in the first place! It only gets onto hair by physical contact, like when you scratch your head or comb your hair.

 

[Armando Jose]

Hi guys;

It is possible that these studies below enlight us in this issue.

British Journal of Dermatology 2001; 144: 297±304.
Hair density, hair diameter and the prevalence of female
pattern hair loss

Most women classified as having
female pattern hair loss had hair densities within the lower half of the normal distribution.



Biochemical and trichological characterization of diffuse alopecia in women
A biphasic distribution of hair diameter was evident in subjects who had percentages of vellus hair and telogen hair ?30 mm in length that were above the control ranges



Natural progression of male pattern baldness in young men
Rushton et al
Clin Exp Dermatol 1991;16:188-192
http://www.ncbi.nlm.nih.gov/entrez/quer ... t=Abstract

Clin Exp Dermatol. 1991 May;16(3):188-92.


Natural progression of male pattern baldness in young men.

Rushton DH, Ramsay ID, Norris MJ, Gilkes JJ.

School of Pharmacy & Biomedical Sciences, Portsmouth Polytechnic, UK.

Twenty-six men who presented with male pattern baldness (androgen-dependent alopecia), were quantitatively evaluated for scalp hair variables and compared with 13 age-matched controls.
Compared to controls, significant mean differences for hair variables were found in the frontal-vertex area, while in the occipital area, a reduction in total hair density (hairs/cm2) was the only significant (P less than 0.05) finding.
A large proportion (48.5%) of meaningful hair (non-vellus hair) was less than or equal to 40 mm in length, yet had diameters similar to hairs growing much longer. In controls, these hairs accounted for only 12.2% of the total population.
Compared to baseline, mean values from the frontal-vertex area of subjects with androgen-dependent alopecia were significantly lower for total hair density, meaningful hair density (non-vellus hairs/cm2) and percentage of hair in the anagen growth phase, 12 and 24 months later.
During this time, total hair density decreased by 6.5% after 12 months and by 11.9% after 24 months. Similarly, meaningful hair density declined at 12 months by 10.8% and by 22.7% after 24 months.
No change in any hair variable was detected in controls after 12 or 24 months. Our findings suggest that medications capable of maintaining the existing hair population should be regarded as effective treatments for this condition. Left untreated androgen-dependent alopecia progressively deteriorates.
The induction of non-vellus hairs less than or equal to 40 mm in length to grow longer, would substantially improve the aesthetic profile without the need to generate new hair.

Dr Rushton holds the post of Honorary Senior Lecturer in
Trichological Sciences at the School of Pharmacy and
Biological Sciences, University of Portsmouth. He has a
PhD in 'Chemical and Morphological Properties of Scalp
Hair in Normal and Abnormal States',





Morphometry of normal scalp hair follicles
Brenner at al
Ann Bras Dermatol 2006;81:46-52


Phototrichogram Analysis of Japanese Female Subjects
with Chronic Difuse Hair Loss
http://www.nature.com/jidsp/journal/v8/ ... 0103a.html

Hair density revealed the highest F-value (20.8),
indicating this to be the most important parameter in female
difuse alopecia.

The second factor is hair’s thickness
http://www.nature.com/jidsp/journal/v8/ ... gure-title


Normal head-hair length is correlated with its diameter
J. Nissimov
Department of Experimental Medicine and Cancer Research, Faculty of Medicine, Hebrew University, Jerusalem, Israel




Armando