Friday, September 28, 2012

As Seen on TV! Restoring Hair with LASERS!!!!!!

The author's rapidly-expanding forehead.
Anyone who watches TV, reads magazines, or flips through catalogs has seen some interesting products. Maybe they seem plausible to you, maybe they don't. However, a little investigation shows they are based less on science and well...actually working, and more on wishful thinking. At worst they're actual con-jobs, designed to separate you from your money as efficiently as possible (which I guess is a certain standard of success). As a result, we at Double X Science bring you “As Seen on TV!” In these features, we'll look at some of the products shilled on talk shows and infomercials, items lurking between the articles you read in magazines, or things you might find on the shelves of the stores where you shop.
I admit it, I'm a balding dude. My forehead is gradually taking over my entire scalp, replacing my formerly thick and curly hair with a vast expanse of pink skin. Yes, dear readers: My hair was once so thick and curly that, when I wore it long and in a ponytail, ladies would ask me for my secret. (The answer: Wash it every other day with some brand of cheap shampoo and let it air dry. Don't tell.) I don't like the fact of my impending baldness, so I'm sympathetic toward defoliation-sufferers who want to bring their hair back at any cost.

On the other hand, I don't think I'll invest in any of the hair restoration products advertised in the SkyMall catalog I picked up on my flight to my brother's wedding in San Francisco. I counted seven products in this single catalog promising to restore hair in one way or another, either reversing baldness or filling in thin patches on the scalp –- and that doesn't include hair-coloring, extensions, or other options. I won't cover all of them, but no fewer than three products pledge to bring hair back through the magic of lasers.

Ah, lasers. They may not have the mystique of magnets or the nous of “natural”, but they are a frequent ingredient in modern snake oil. (Come to think of it, one of the hair-restoration products may have contained snake oil. I don't want to ask.) But while lasers can help correct nearsightedness in some cases, perform minimally invasive surgeries, and remove hair, color my scalp skeptical about their ability to restore hair.

First, a disclaimer: I'm not a biologist, a doctor, medical researcher, or in any field related to those. I'm a physicist, so the closest I ever get professionally to this topic is the “no-hair" theorem in black hole physics. The "no-hair" theorem says that black holes have very few distinguishing characteristics: only mass and rotational rate (and technically electric charge as well, though it's hard to build up enough charge to make a difference). The analogy is that, if all humans were completely hairless, we would have a lot fewer ways to tell each other apart. In other words, this ain't my area, so bear (bare) with me!

Night on Baldhead Mountain

Hair loss can occur for a wide variety of reasons: chemotherapy, a number of unrelated diseases, even stress. However, as humans (both men and women!) age, we all tend to lose our hair to some degree. The effect is most pronounced in male pattern baldness (a bare patch on the top of the head merging over time with the growing forehead to leave a fringe around the edges of the scalp) or female pattern baldness (a general loss of hair at the top of the scalp). However, past the age of 80, nearly everyone starts losing hair, regardless of genetics, diet, or health.

The reasons, as with so many other things, are hormonal. Hair production is governed by sex hormones: most famously testosterone, but also a less well-known cousin known as dihydrotestosterone (DHT). In some people, DHT commands the follicles -- the small organs in the skin that produce and feed hair -- to shrink, producing ever-finer hair until they cease operating entirely. Thus, gradual hair loss of the usual (as opposed to disease- or circumstance-derived) variety is generally preceded by the hair itself becoming thinner and fuzzier.

My naive understanding of the biology of hair loss leads me to suspect that since hormones are the culprit behind hair loss, then any hair restoration should address those hormones in some way. That alone makes me suspicious of the laser-based products SkyMall peddles. To see why, let's look at lasers themselves.

Lasers (without sharks)

The word "laser" began as an acronym: Light Amplification by the Stimulated Emission of Radiation. The details could be an Everyday Science or Double Xplainer post in their own right, but here's the short version. The lasers used in the SkyMall products are LED lasers, meaning they are based on the underlying physics as LED lights. An electric current kicks electrons or other electric charge carriers from one type of material to another across a junction. The excess energy the electric charge sheds during this process is given off in the form of a photon, a particle of light. Since the same amount of energy is involved every time, light from LEDs is nearly monochromatic, meaning it is almost purely one color.

The "amplification" part of the name comes by putting the LED into a special kind of cavity with reflective walls. These walls set up standing waves for the light, which interfere constructively like vibrations in a guitar string, making them brighter. However, unlike guitar strings, the production of the light in lasers is a self-feeding process, resulting in the different parts of the system synchronizing until they emit photons in concert with each other. It's really interesting stuff, and while it's somewhat complicated, there's nothing really mysterious or magical about it, any more than magnets are magical.

In fact, LED lasers are so unmagical that you can buy them as cat toys. LED lasers are the inner workings of laser pointers, which you can buy very inexpensively at any number of shops.

The smell of frying follicles

One of three laser-based hair-restoration products from SkyMall.
This one features built-in headphones, so you can at least listen
to music while you sit around looking like a fool. However,
I recommend a cheaper set of headphones, since the $700
price tag is a bit steep, and you'd get the same result with
regards to hair restoration.
Laser hair removal uses intense lasers to selectively heat the follicles in the skin, hopefully avoiding damage to the rest of the skin. This process can slow down hair growth and cause the hair to fall out of the treated follicles, but it doesn't always actually stop it: the treatment must be continued for a long term. Basically, the laser is damaging the follicle.

As you can imagine, that also makes me skeptical that lasers can stimulate new hair growth. Lasers produce light...and that's it! In addition to the usual red lasers like in laser pointers, manufacturers also make infrared lasers, which are useful for surgery. While we perceive infrared as heat (which is why sunshine feels warm), I don't think merely warming the scalp is going to make hair grow faster, or else you wouldn't need lasers at all -- an electric blanket would do just as well. Too much heating and we're back at laser hair removal.

Similarly, visible-light lasers like the kind that seem to be in these SkyMall products simply produce red light. Because ordinary light bulbs produce a broad range of colors (white light is a mixture of all the visible-light wavelengths), sitting under a desk lamp would expose your scalp to red light. Yes, it wouldn't be as intense as lasers, but you could do the same trick with a laser pointer from Schtaples (the Scmoffice Schmupply Schtore), provided you have the patience to hold it against your scalp for long periods of time.

The author engages in home laser hair restoration, while his cats
meow around his feet.
So, to summarize:
  • Hair loss in its most common forms is hormonal, so it's unclear to me that light (whether laser or otherwise) has anything to do with it. Hair removal can be achieved with lasers, but that involves causing damage to hair follicles, not using anything intrinsic to light.
  • Lasers are simply very monochromatic light sources, that use synchronization of atoms on the microscopic level to do their business. There's nothing in a laser that isn't in ordinary light bulbs, though you can make things far more intense with a laser. However, high intensity brings us back to laser hair removal, not restoration.
  • As always, if a product sounds miraculous, it's probably bunkum. If all it took to regrow hair was a glorified laser pointer, nobody would be bald! LED lasers are cheap and ubiquitous; we could all restore our hair without paying a company $700 (and listen to the music on inexpensive headphones, to boot).
Now if you'll pardon me, I'll get back to shining this laser pointer at my scalp.

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