Yet again (see my 2013 blog post), scientists from the University of Southern California (USC) surprised us this week by publishing a groundbreaking study related to hair. This one was on how strategic plucking induces new hair growth — in mice :-( The work was led by Dr. Cheng-Ming Chuong and published in the prestigious Cell magazine, giving it significant credibility. You can see the entire paper on Dr. Chuong’s website.
I am not sure why such a simple experiment has not yet been attempted on humans. I was not too motivated to write this post several days ago when the news first came out and I read the word “mouse” in there. In fact I have not even bothered to read most of the pages in hair loss forum threads related to this news yet.
Here are some links to this important story: link1 from the USC website; link 2 from the LA times where they discuss macrophages; and link 3 from BBC where they mention a potential cream or injection for this. The results varied significantly depending on the number of follicles plucked and the area from which they were plucked. When done correctly, new hair even grew outside the plucked area. This type of phenomenon is seen in many areas of biology and is termed as “Quorum Sensing“. The luckiest mouse had 200 hairs plucked and grew back 1,300 hairs.
One of the quotes from the first link in the last paragraph was interesting:
As a dermatologist, Chen knew that hair follicle injury affects its adjacent environment, and the Chuong lab had already established that this environment in turn can influence hair regeneration.
I wonder if this result from plucking is then also related to some extent to other injury type phenomena that can result in new hair growth such as:
- Numerous anecdotal reports of people seeing more hair on a limb after a cast or splint has been removed months after an injury.
- Dermarolling type intentional injuries to hair follicles.
- Mechanotherapy type intentional injuries to hair follicles.
- And maybe even lasers (LLLT) partly working by causing some injury (heating) to hair follicles?
If I was a bit more driven and had more spare time, I would try to experiment with plucking my body hair in both my arms and maybe legs too. I would try different amounts/densities and areas just as in the mouse experiment and take lots of photos. If any one area became thick with new body hair, I would be quite surprised.