Under Hair
As you may have noticed, pubic hair is quite different from hair on the head. Short, coarse, and curly, public hair never gets a chance to grow long because it has a short growth period. Within six months, the follicle dies and the hair falls out. Pubic hair—which acts as a buffer to reduce chafing and maybe to hide our genitals—provides a large surface area to disperse the naturally smelly sweat. Many animals use the odor of sweat from the groin and underarms (pheromones—see chapter 10 on sex and attraction) to attract the opposite gender. Today, it more often keeps people on the other side of the elevator.
To learn how you lose hair, you first have to understand how it grows. Hair goes through its own growth cycle that’s unrelated to seasons or hormones or anything else. It’s a random biological process that’s dictated largely by your genetic disposition. The two main phases:
Anagen (active): Cells in the root are dividing quickly and pushing the hair out. It averages two to three years.
Telogen (resting): This phase lasts for about 100 days on the scalp. Consider it hair hibernation—the follicle is completely at rest.
FACTOID
Some people may try to persuade you to have your hair examined for heavy metals such as mercury, but those tests (in which they take a quarter-size clump of your hair, including the follicles) are inconsistent. While there are some reliable results for drugs of abuse, the preferred method of testing should still be peeing in a cup.
Doctors don’t know why certain hair follicles are programmed to have a shorter growth period than others. One suspected factor for age-related male-pattern baldness is a person’s level of androgens—the “male” hormones that are actually produced by both men and women. Take a look at Figure 2.2. For many years, people believed that a predominance of testosterone was the root cause of baldness, but it’s not quite that simple. We do know that we lose hair especially fast if it is exposed to dihydrotestosterone (DHT, which comes from metabolism of testosterone). It’s believed that the exposure of follicles to levels of testosterone that are normal for adult males causes the hair follicles to go into a resting state. This DHT is formed in the testes, prostate, adrenals, and hair follicles themselves through an enzyme called 5-alpha reductase. The enzyme raises the levels of DHT, and that’s why there’s a link between higher levels of this enzyme and areas of baldness. DHT changes healthy follicles to follicles that grow thin dwarf hairs—hairs that resemble peach fuzz. Essentially, DHT shrinks hair follicles, making it impossible for healthy hair to survive. Drug companies have targeted this process by making antibaldness medication that inhibits 5-alpha reductase, the enzyme that makes DHT. (Some of the infrequent side effects of these meds include impotence, decreased libido, and breast enlargement.)
Figure 2.2 Shiny Scalp The reason we go bald isn’t because of our mother’s father. It’s because of DHT (a product of testosterone), which first makes hair turn thin and fuzzy and then makes it fall out from our head to the shower drain. The distinguished graying around the temples (and elsewhere) occurs as we lose melanocytes.
The Future of Hair Loss Treatments
Anybody who’s lost a lot of hair probably knows why the race to find a cure for baldness is a competitive one—there are a lot of willing customers ready to try and buy. Many different therapies are being tested as we speak, including gene therapy (in which genes involved in hair growth would be delivered directly to the follicle) and chemicals that increase hair’s growth cycle. One of the more interesting ones involves cloning—a process in which scientists would clone your hair so you could donate to yourself all the hair you’d ever need or want.
Now, age-related baldness isn’t the only reason why clumps of hair start falling from the head like raindrops from the sky. Other causes, especially for women, include low iron levels and anemia (low blood count), recent anesthesia for surgery (it’s the stress of the surgery and the pressure on one area of the head, not the anesthesia), menopause or being postpartum, autoimmune diseases such as lupus, thyroid disease, and polycystic ovarian disease (PCOS).
FACTOID
People who constantly pull their hair out aren’t overcrazed parents; they’re more likely suffering from a form of obsessive-compulsive disorder. This habit—called trichotillomania—keeps happening because the puller is always searching for the perfect “pull” (so they keep on pulling when it’s not). The treatment: Follow the addiction principles in Chapter 8, or just make it harder to do, by wearing gloves at night or keeping a rubber band handy so you can play with that rather than fiddling with your follicles.
Rapid hair loss is often a strong sign that you ought to have a battery of tests to evaluate your nutrition, health, and hormone levels. And that makes an important point: Hair loss isn’t just an appearance issue; it can be a sign that something wacky is going on elsewhere in your body. Inflammation in the scalp, from an overdose of sun or from seborrheic dermatitis, can speed up hair loss. More often than not, it’s a hormone issue—especially one involving your thyroid gland. In women especially, it’s common to experience a decline in thyroid hormone (that’s called hypothyroidism), where some of your bodily systems slow down. Scalp hair loss or facial hair growth is a sign that you should have your hormone levels checked. We recommend having your thyroid-stimulating hormone checked every other year if you’re losing hair, or, for all others, once at age 20, then at age 35, and every other year after age 50 (TSH is the trigger from the brain that tells your thyroid gland to make thyroid hormone). If your level of thyroid hormone is low or if it’s normal but you are experiencing thyroid-related symptoms, you can be (and usually need to be) treated with a synthetic (sometimes bioidentical) hormone. You’ll need to be rechecked six weeks later to see if the supplemented dose is enough. For a man, a decline in the need to shave signals a decrease in testosterone (for a woman, it’s the same clue if she needs to shave her legs less often).
Hairloom
We all know people have varying degrees of body hair: Some men have chests and backs that double as winter coats, while others have torsos that are slicker than an ice patch. That begs the question of why we even have body hair in the first place. Of course, for early humans, hair kept them warm, protected them from cuts and scrapes, provided camouflage, and even served as a nice handhold for the young. The reason why we lost a lot of body hair over time isn’t because we invented heaters and parkas. More likely, our ancestors started having to hunt in hot, tropical areas—and bare skin adds to the efficiency of our cooling system. The reason why we kept the tuft at the top? Many experts agree that it had to do with a mating ritual that went a little something like this: The male with the most impressive hair—or he who could make it look that way—frightened away his rivals, got his girl, and fathered the next generation. Hence, head hair played a major role in obtaining a partner and successfully producing offspring.
FACTOID
The hair you have in your ears comes to life only as you age. As one of the pleasures of growing older, this hair protects you from insects that find the ear canal interesting. Also, like sheep, you recruit dormant follicles so you can grow more hair to keep yourself warm in the winter.
How Hair Is Destroyed
Our hair occasionally needs lubrication the way other parts of our bodies do.* But with hair, the things many of us do to help it are actually hurting it. Most of us treat shampoo as if it’s toothpaste for our head—we’ve got to use it every day. But that doesn’t have to be the case. Some people find that their hair has just as much body and shine without shampooing every day (and they like the fact that they can take a break from putting additional chemicals on their head). On the other hand, if shampooing is a Zen experience for you, its calming benefits may well do more for
