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Baldness
See also baldness treatments.
Alopecia, commonly known as baldness, is a set of disorders which involves the state of lacking hair where it would normally grow, especially on the head. The most common form of baldness is a progressive hair-thinning condition that occurs in adult humans and other primate species. Nonetheless, the severity and nature of condition can vary greatly; it ranges from male and female pattern alopecia (alopecia androgenetica), to alopecia areata, which involves the loss of some of the hair from the head, alopecia totalis, which involves the loss of all head hair, to the most extreme form, alopecia universalis, which involves the loss of all hair from the head and the body. Treatment for alopecia has limited success. The more hair lost, the less successful the treatment will be. The psychological implications of alopecia include stress, anxiety and depression, and can in many cases involve issues relating to identity change, particularly when the eyebrows and eyelashes are also lost. Hair loss is sometimes the result of chemotherapy treatment for cancer sufferers.
Male pattern baldness is thought to occur in varying forms in about 66% of adult males at some point in their lives.[1] It is characterized by hair receding from the lateral sides of the forehead, known as "receding hairline" or "receding brow." An additional bald patch may develop on top (vertex). The trigger for this type of baldness, which is also known as androgenic alopecia, is currently believed to be 5-alpha reductase, an enzyme that converts the hormone testosterone into dihydrotestosterone (DHT), which, in genetically-prone hairs on the scalp, inhibits hair growth. Onset of hair loss sometimes begins as early as end of puberty, and is mostly genetically determined. Male pattern baldness is classified on the Hamilton-Norwood scale I-VIII.
Female pattern baldness, in which the midline parting of the hair appears broadened, is less common. It is believed to result from a decrease in estrogen, a hormone that normally counteracts the balding effect of testosterone, which normally occurs in women's blood. Female pattern baldness is being classified on the Ludwig scale I-III.
There are several other kinds of baldness. Traction alopecia is most commonly found in people with ponytails or cornrows that pull on their hair with excessive force. Wearing a hat shouldn't generally cause this, though it is a good idea to let your scalp breathe for 7 hours a day.[2] Traumas such as chemotherapy, childbirth, major surgery, poisoning, and severe stress may cause a hair loss condition known as telogen effluvium. Some mycotic infections can cause massive hair loss. Alopecia areata is an autoimmune disorder also known as "spot baldness" that can result in hair loss ranging from just one location (Alopecia areata monolocularis) to every hair on the entire body (Alopecia areata universalis).
Baldness - Mechanism of male pattern baldness
While the precise mechanism which underlies androgenic alopecia is unknown, a high level of dihydrotestosterone (DHT) is crucial in initiating the process. DHT is, ironically, a hair growth stimulator. Testosterone is synthesized from pregnalone which is formed from cholesterol. DHT is formed from Testosterone with the conversion from testosterone to DHT being mediated by 5-alpha reductase. There are two subtypes of 5-alpha reductase and drugs which block one type may not block the other.
While androgens (the general class of male hormones which includes testostrone and DHT) levels may be similar in men who have male pattern baldness and those who have hair, people with more 5-alpha reductase or a greater density of DHT receptors may be more vulnerable to the effects of DHT. Surprisingly, men with male pattern baldness have, on average, significantly lower levels of total testosterone, though they did not have significantly lower levels of unbound androgens in their blood.[3]
Spiking androgen levels, caused by intense weight training, sudden weight loss, taking anabolic steroids or other synthetic androgens and other causes can promote the balding process. The vast majority of anabolic steroids contribute to hairloss, since most anabolic compounds break down to form DHT at some point.
How DHT causes hair loss is hotly debated.
American research tends to focus on DHT, DHT receptor density in the scalp and 5-alpha reductase levels in the scalp as causes of baldness.
Japanese research may cover these topics but also is more likely to cover the increase in sebum (scalp oil) production caused by DHT in the scalp, and the increase of Pityrosporon ovale, a pathogenic yeast which has been linked to dandruff and eczema, and which feeds off of sebum. Issues related to diet are also more likely to be covered. Possibly this is because male pattern baldness has increased very sharply in Japan since the end of World War II along with an increase in fatty foods and average height, focusing public attention on various lifestyle differences.
Most pharmaceutical treatments which stop or slow the balding process work by limiting the creation of DHT. In ideal situations this may cause a person's hairline to revert to what it was a year ago (since follicles which were resting but healthy will be active again), though it is difficult to reverse more than a year of hair loss without surgery.
Since sex hormone binding globulin is reduced by high insulin levels, reducing insulin levels should also increase levels of sex hormone binding globulin. Higher SHBG binds to testosterone, preventing its conversion to DHT. Less free testosterone means that less testosterone will be converted into DHT, even if total testosterone levels are very high.
Statistically, men who are bald are more likely to be insulin resistant and more likely to suffer cardiovascular disease. There seems to be a correaltion between male pattern baldness and metabolic syndrome, though androgens are not shown to cause heart disease or metabolic syndrome\diabetes directly. High insulin levels seem the likely link between the two conditions.
Chronic infection with a diseases such as Chlamydia, exposure to pathogenic mold, and high levels of stress can exacerbate androgenic alopecia. How this happens isn't always clear. Some types of stress can cause decreases in plasma levels of sex hormone binding globulin, among other responses.
Alopecia areata, List of famous bald people
Baldness - Evolutionary theories of male pattern baldness
There is no consensus regarding the details of the evolution of baldness. Most theories regard it as resulting from sexual selection. A number of other primate species also experience hair loss following puberty, and some primate species clearly use an enlarged forehead, created both anatomically and through strategies such as frontal balding, to convey increased status and maturity.
One theory, advanced by Muscarella and Cunningham, suggests baldness evolved in males through sexual selection as an enhanced signal of aging and social maturity, whereby aggression and risk-taking decrease and nurturing behaviours increase.(1) This may have conveyed a male with enhanced social status but reduced physical threat, which could enhance ability to secure reproductive partners and raise offspring to adulthood.
In a study by Muscarella and Cunnhingham, males and females viewed 6 male models with different levels of facial hair (beard and moustache or clean) and cranial hair (full head of hair, receding and bald). Participants rated each combination on 32 adjectives related to social perceptions. Males with facial hair and those with bald or receding hair were rated as being older than those who were clean-shaven or had a full head of hair. Beards and a full head of hair were seen as being more aggressive and less socially mature, and baldness was associated with more social maturity.
Baldness - Approaches to baldness
Baldness - Psychological implications
The psychological implications for individuals experiencing hair loss vary widely. There can be a general societal anxiety surrounding the process of hair loss, but some individuals view it as nature taking its course.
Some balding men may feel proud of their baldness, feeling a kindred relationship with famous charismatic bald film actors such as Yul Brynner, Telly Savalas, Ben Kingsley and Patrick Stewart, who have been considered masculine and handsome in part because of their most obvious distinguishing feature.
Baldness - Preventing and reversing hair loss
For more information, see the main article on Baldness treatments
It is easier to prevent the aging and falling out of healthy hairs than to regrow hair in follicles that are already dormant. However, there are products that have good success rates with maintenance and regrowth, including the scientifically proven finasteride (marketed in the U.S. as Propecia) and minoxidil (marketed in the U.S. as Rogaine, and some places as Regaine). The prospective treatment of hair multiplication/hair cloning, which extracts self-replenishing follicle stem cells, multiplies them many times over in the lab, and microinjects them into the scalp, has been shown to work in mice, and is currently under development, expected by some scientists to be available to the public in 2009-2015. Subsequent versions of the treatment are expected by some scientists to be able to cause these follicle stem cells to simply signal the surrounding hair follicles to rejuvenate.*
Topical application of ketoconazole, which is both an anti-fungal and a potent 5-alpha reductase inhibitor, is often used as a suppliment to other approaches.
Interestingly, placebo treatments in studies often have reasonable success rates, though not as high as the products being tested, and even similar side-effects as the products. For example, in Finasteride (propecia) studies, the percent of patients with any drug-related sexual adverse experience was 3.8% compared with 2.0% in the placebo group.[4] Proponents of alternative therapies believe that the majority of cases of hair loss that progress despite treatments do so because the people believe no such cure can occur. In this view, this belief, which is prevailing in the modern civilised world and continuously reinforced by medical science, is the main obstacle for effectively finding and applying a cure.
Regular aerobic exercise can help keep androgen levels naturally lower while maintaining overall health and lowering stress, though weight training may have a detrimental effect on hair by increasing testosterone levels. (There is some evidence that irregular, short bursts of exercise can be worse for health than no exercise at all)
Stress reduction can be helpful in slowing hair loss.
Immunosuppresants applied to the scalp have been shown to temporarily reverse hair loss, though the possibly lethal side effects of this treatment make it untennable.
Saw Palmetto a.k.a. Serenoa repens is an herbal DHT inhibitor often claimed to be cheaper and have fewer side effects than finesteride and dutasteride. This claim however is inaccurate. In studies, Saw Palmetto was shown not to reduce serum DHT levels to any significant extent. Unlike Propecia (finasteride), which reduces serum DHT levels noticeably, Saw Palmetto is not considered an effective treatment for hair loss. It is also not natural as it can and does modify some hormonal processes in the body just as potently as synthetic medications can.
Polygonum Multiflorum is a traditional Chinese cure for hair loss. Whether the plant itself is useful, the general safety and quality control of herbs imported from China can be questionable.
Beta Sitosterol, which is a constituent in many seed oils, can help to treat BHP by lowering cholesterol. If used for this purpose, an extract is best. Consuming large amounts of oil to get at small quantities of beta sitosterol is likely to exacerbate male pattern baldness.
Resveratrol, from grape skins, is a lipase inhibitor. By decreasing the body's ability to absorb fat through the intestine walls, it reduces the total fat and calorie content of a person's diet.
While drastic, broad spectrum anti-androgens such as flutamide are sometimes used topically. Flutamide is potent enough to have a feminizing effect in men, including growth of the breasts.
There are many misconceptions about what can help prevent hairloss, one of these being that frequent ejaculation may have an influence on MPB. While ejaculation significantly lowers levels of relaxin (a 5-alpha reductase inhibitor) in a male's body and does cause testosterone levels to temporarily elevate the claim that frequent ejaculations can cause baldness is often viewed with skepticism. Higher testosterone levels may correlate with both hairloss and increased sex drive in predisposed individuals. Another false reason is "blood-flow" theory which led men to stand on their heads in the 1980's, and can be found in the advertising for many of the fake hair-loss treatments for sale on the internet. While Minoxidil is a vasodialtor and is speculated to work, in part, by increasing blood flow to hair follices, there is no evidence that standing on one's head can alleviate baldness.
Baldness - Concealing hair loss
One method of hiding hair loss is the comb over, which involves restyling the remaining hair to cover the balding area. It is usually a temporary solution, useful only while the area of hair loss is small. As the hair loss increases, a comb over becomes less effective.
Another method is to wear a hairpiece - a wig or toupee. The wig is a layer of artificial or natural hair made to resemble a typical hair style. In most cases the hair is artificial. Wigs vary widely in quality and cost. The best wigs - those that look like real hair - cost up to tens of thousands of dollars. Organizations such as Locks of Love and Wigs for Kids collect individuals' donations of their own natural hair to be made into wigs for young cancer patients who have lost their hair due to chemotherapy or other cancer treatment.
Baldness - Embracing baldness
Baldness - Common baldness myths
There are many myths regarding the possible causes of baldness and its relationship with one's virility, intelligence, ethnicity, job, social class, wealth etc. Most of them can be dismissed by the existence of many counterexamples or by a lack of sufficient scientific research. However there is some research strongly linking an individual's verbal recall ability from week to week to their androgen level. Higher androgen levels conferred greater recall.
In the ancient world, if a bald person;
- His mental development was probably not stunted by malnutrition during his crucial formative years. and - He was more likely to be wealthy, and thus have access to a formal education.
- "Intellectual activity or psychological problems can cause baldness."
This myth probably was inspired by the fact that the human brain is located inside the skull, very close and just below where hair grows, and so it was thought that the use and abuse as well as mental diseases could have negative effect on hair growth and number. It may also be due to the fact that cholesterol is involved in the process of neurogenesis and also the base material from which the body ultimately manufactures DHT.
This is sometimes used as a stereotype in films, where the more intellectual or rather frustrated characters are most usually portrayed as bald and generally unattractive, as opposed to the main characters which are usually portrayed as attractive, fit, mentally stable and generally with no apparent hair problems.
This same myth normally extends to considering people having intellectual jobs more prone to baldness problems compared to manual laborers, sometimes further extending the myth to male college or university students when compared to workers of the same age. The myth is suspect because counterexamples can be found in any case.
- "Baldness can be caused by emotional stress, sexual frustration etc."
While emotional stress can have a part in causing baldness, again it is easy to find counterexamples like non-frustrated and non-stressed people with hair loss problems as well as stressed and/or frustrated people with no hair loss problem at all.
This myth also suggests that a vicious circle between hair loss and emotional stress/sexual frustration can take place, although only one part of it can be scientifically explained (hair loss causing low esteem and then frustration, but not vice versa).
- "Bald men are more "virile" or sexually active than others."
This myth probably stems from the fact that some forms of baldness in some predisposed individuals are caused by androgens, and removal of androgens (by castration) prevents baldness or stops it from progressing further. Yet counterexamples can be found, like men with perfect hairlines and similar levels of androgens or men with sensitivity to androgens causing hair loss but which are not very sexually active.
- "Shaving hair makes it grow back stronger"
Proposed as a popular remedy against baldness, it's very probably just an illusion similar to the one perceived after shaving one's beard or mustache. Shaving one's head doesn't increase the number of healthy hair present on the scalp, and, when the remaining hair has grown a few millimeters, no enhancement in thickness or overall quality can be observed.
A very similar stereotype exists even between the various European ethnic groups, when comparing people of Southern European descent with those of Northern European, Germanic or Slavic origins, with the stereotype summarily describing the "Southern Europeans" as darker-skinned, with more body hair, with the women more prone to cellulite problems and the men more prone to baldness, a stereotype probably developed under times of war or diplomatic tensions between European countries.
- "Baldness is inherited from the mother's side of the family"
One of the identified genes involved in male pattern baldness is located on the X chromosome, which is inherited only from the maternal side, but this one gene does not explain all the cases of male pattern baldness. Baldness in a child cannot be predicted only from the mother's lineage. There are probably other unidentified autosomal genes that are also involved. In other words, genetics does play a role in male pattern baldness, but the genes can come from either parent, not just the mother.
Baldness - Trivia
- John D. Rockefeller had an extreme case of alopecia that caused him to lose all of the hair on his face, including his eyebrows and eyelashes. Another famous person who suffers from similarly severe alopecia is Italian football referee Pierluigi Collina. Actor Patrick Stewart lost most of his hair to alopecia by age 19.
- Eunuchs do not go bald. [6]
- Baldness is not only a human trait. Some other primates, such as Chimpanzees, stump-tailed macaques, and South American nakari show progressive thinning of the hair on the scalp after adolescence. [7]
- A common characteristic of many Vulture species is a bald head, devoid of feathers. This is likely a result of natural selection, because a feathered head would become spattered with blood and other fluids, and difficult to keep clean.
- The American Bald Eagle is not really bald. The feathers on the head of this bird are white, in contrast to the brown feathers of the body.
Baldness - Reference
- Muscarella, F., & Cunningham, M.R. (1996). The evolutionary significance and social perception of male pattern baldness and facial hair. "Ethology and Sociobiology" journal (volume 17: 99-117 (1996).
- Rossi S (Ed.) (2004). Australian Medicines Handbook 2004. Adelaide: Australian Medicines Handbook. ISBN 0-9578521-4-2
See also
- Alopecia areata
- List of famous bald people
Other related archives*, 1, 5-alpha reductase, Alopecia areata, American Bald Eagle, Australian Medicines Handbook, Baldness treatments, Ben Kingsley, Chimpanzees, DHT, Eunuchs, Germanic, Hamilton-Norwood scale, John D. Rockefeller, List of famous bald people, Ludwig scale, Northern European, Patrick Stewart, Pierluigi Collina, Rogaine, Saw Palmetto, Serenoa repens, Sitosterol, Slavic, South American, Southern European, Telly Savalas, Traction alopecia, Vulture, Yul Brynner, actors, adult, aggression, alopecia, alopecia areata, alopecia totalis, alopecia universalis, anatomically, androgens, autoimmune disorder, autosomal, baldness treatments, brain, cancer, castration, cellulite, charismatic, chemotherapy, college, comb over, consensus, cornrows, dihydrotestosterone, diplomatic, ejaculation, enzyme, estrogen, evolution, facial hair, films, finasteride, flutamide, follicles, football, forehead, genetically, hormone, ketoconazole, macaques, male pattern baldness, males, masculine, maturity, mental diseases, metabolic syndrome, minoxidil, mycotic, nurturing behaviours, perceptions, placebo, ponytails, primate, primates, puberty, referee, relaxin, sebum, sexual selection, shaving, social class, species, status, stereotype, stress, students, telogen effluvium, testosterone, toupee, university, vicious circle, virility, war, wig, workers
 Adapted from the Wikipedia article "Baldness", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki |
