Hair Geekery

Oh mi gods, there really IS hair science! Well, I mean, duuuh, obviously, but there are even classes and conferences!!! Most of it seems to be focusing on how best to make better products to have people spend even MORE money....I so wanna subvert that - learn the science and then reframe it to include kitchen witchery.....

That's a picture of freezedried hair, by the way - the blue strands are hair, the bumpy brown stuff is the scalp skin, and the salmon colored bobbles around the base of the hair is the follicle and the porous pink stuff is the sebum gland - this shot is magnified a mere 100 times from lifesize. At that size, an 'average' strand of hair would be about 1/5 inch wide.

Funnily enough, hair studies came up online today around the 'infamous' statement that african hair grows slower than Asian/Caucasoid. I found one reference yesterday, and the thread had a link to an actual study - abstract only, of course. I have a deep craving and desire for a subscription to HighBeam now - it makes my toes curl thinking of all the information that's there!
Anyhow - here's the summary of the data around growth rates, basically:

Asian hair grows an average of 1.3 cm a month. (0.51 inches/month)
Caucasian hair grows an average of 1.2 cm a month (0.47 inches/month)
African hair grows an average of 0.9 cm a month. (0.35 inches/month)

The common consensus is that hair grows an average of 1/2 - 1/4 inch a month, so the studies support 'common knowledge'.

The studies appear to be done using phototrichograms (high magnification pictures of the scalp), so there isn't much lee-way around product usage, health, hair chemicals used, etc, etc.

Interestingly enough, density, on the other hand, is slightly different.

Caucasian hair on average has 227 ± 55 hairs per sqcm (~130,000
total)
African hair on average has 190 ± 40 hairs per sqcm ( ~108,000 total)
Asian hair on average has 170 ± 35 hairs per sqcm (~96,000 total)

Most interesting. I wonder if the lack of density - hrmm, I suspect it would extend over the entire body, and I'd have to say that the average white dude is a heck of a lot hairer than the average black man, and the average asian man is almost body hair free.

I found this great definition set too (gods, how I love Wiki!)

Anagen is the active growth phase of hair follicles. The cells in the root of
the hair are dividing rapidly, adding to the hair shaft. During this phase
the hair grows about 1 cm every 28 days. Scalp hair stays in this active
phase of growth for 2-6 years. The amount of time the hair follicle stays in the
anagen phase is genetically determined. At the end of the anagen phase an
unknown signal causes the follicle to go into the catagen phase.

That bit there is the 'growth cycle' that most people talk about - the time during which the hair is actively growing......the maximum length of this phase is genetically determined, as is your actual maximum growth rate - however, your current health and nutrition dictate whether you will actually reach that. For most people in the US, I seriously doubt they are healthy enough to actually reach their hairs maximum potential - thus, the hair supplements. I can SO understand the reasoning (and I know my butt needs to hop on - I don't even want to THINK about how depleted I am of trace minerals!), but it's SUCH a bloody pain, popping all those pills, besides the fact that I don't think taking the pills even begins to give you the actual balance of bioavailable minerals required. *sigh*

And that 'unknown signal' bit is innnnttttteeeeresting, indeedly.

The catagen phase is a short transition stage that occurs at the end of the
anagen phase. It signals the end of the active growth of a hair. This phase
lasts for about 2-3 weeks while a club hair is formed.

The telogen phase is the resting phase of the hair follicle. At any given time,
10%-15% of all hairs are in the telogen phase. This phase lasts for about 100
days for hairs on the scalp and much longer for hairs on the eyebrow, eyelash,
arm and leg.During this phase the hair follicle is completely at rest and the
club hair is completely formed. Pulling out a hair in this phase will reveal a
solid, hard, dry, white material at the root.About 25-100 telogen hairs are shed
normally each day.

Innnteresting. So, hair that is healthily shed is actually being pushed out of your head by a new hair. Does that mean that the stuff that stops shedding is actually preventing new hairs from growing? Hrrm. I wonder if any of the ayurvedics specifically address shedding - I bet if they do, it's more along the lines of 'thinning' hair - where shed hairs aren't being replaced by the hair that SHOULD have pushed it out.

And, I would think if a LOT of hairs went telogen at the same time, it might look like your hair had stopped growing.

Hrrm.

I've read (and how I wish I could remember where now) where someone was trying to do SOMETHING to have their hair go from anagen to telogen (without hitting catagen) and then back into anagen - basically doubling the 'natural' lifespan of a single strand of hair. Dunno if it's even really POSSIBLE. Tis a thought, though. Or.... I wonder if what they were REALLY trying to do was to short-circuit that 'unknown signal'......

I've saved bunch of new links, and one was a juicy looking one about the biochemisty of hair growth, I think. That would be interesting - as obviously there is SOMETHING telling the follicle to start and stop growing - most likely some hormone. *lol* This will be most interesting.
I'll add new links as I go through them - a lot of the information appears to be repeated (or straight copied) so I'll try to only link the 'richest' sources of data.