Baldness

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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.

It was previously believed that baldness was inherited from a person's maternal father. While there is some basis for this belief, both parents contribute to their offspring's liklihood of hair loss. (see 'baldness folklore' below)

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. Traumas such as chemotherapy, childbirth, major surgery, poisoning, and severe stress may cause a hair loss condition known as telogen effluvium.[2] Some mycotic infections can cause massive hair loss.[3] 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).

Contents 1 Etymology 2 Mechanism of male pattern baldness 2.1 Insulin, Metabolism and androgen levels 2.2 Stress and androgen levels 3 Evolutionary theories of male pattern baldness 4 Approaches to baldness 4.1 Psychological implications 4.2 Preventing and reversing hair loss 5 Concealing hair loss 6 Embracing baldness 7 Baldness folklore 8 Trivia 9 Reference 10 See also 11 External links 11.1 Consumer information pages 11.2 Hair loss specialist directories 11.3 Male Pattern Baldness News 11.4 The relationship between androgenic baldness, metabolism, diabetes and heart disease

Etymology

The term alopecia (al-oh-PEE-she-uh) is formed from the Greek αλωπηξ (alopex), meaning fox. The origin of this usage is because this animal changes its hair two times a year.

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. DHT is formed from testosterone via the enzyme 5-alpha reductase. There are two subtypes of 5-alpha reductase and drugs which block one type may not block the other.

Male pattern baldness is the result of a confluence of several traits. People with more 5-alpha reductase or a greater density of DHT receptors in their scalp as well as those with higher androgen levels may be more succeptable to MPB. Men with androgenic alopecia typically have lower levels of total testosterone, higher levels of unbound/free testosterone, and higher levels of total free androgens including DHT.<ref>http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=14758568&query_hl=18</ref><ref>http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9349747&query_hl=4&itool=pubmed_docsum</ref>

Spiking androgen levels, caused by things such as intense weight training, sudden weight loss, taking anabolic steroids or other synthetic androgens can promote the balding process. The vast majority of anabolic steroids contribute to hair loss, since most anabolic compounds break down to form DHT at some point.

While DHT is crucial for initiating MPB, how DHT causes hair loss is hotly debated.

American research tends to focus on DHT levels in the scalp, 5-alpha reductase levels in the scalp, and DHT receptor density and polymorphism 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 on 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.

In ideal situations, the elimination of DHT 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) and may stop or slow the balding process. However it is difficult to reverse more than a year of hair loss without surgery.

Chronic inflammation caused by diseases such as chlamydia, exposure to pathogenic mold, and high levels of stress can exacerbate androgenic alopecia.

Insulin, Metabolism and androgen levels

Typically, Sex Hormone Binding Globulin or SHBG binds testosterone and controls the amount which is floating 'free' in the blood. Lowered levels of SHBG result in more free testosterone. Increased levels of free testosterone mean more testosterone can be converted into DHT by the enzyme 5-alpha reductase.

Sex hormone binding globulin is reduced by high insulin levels. Thus, when insulin levels are high, free testosterone is increased leading to more DHT. Possibly, increasing the level of free testosterone is one more way for our bodies to deal with high blood sugar. The level of free testosterone, and not total testosterone, is determinant of the level of DHT in the scalp. Thus, the level of DHT is directly linked to insulin levels.

Statistically, men who are bald are more likely to be insulin resistant and more likely to suffer cardiovascular disease. There seems to be a correlation between male pattern baldness and metabolic syndrome, though androgens are not shown to cause heart disease or metabolic syndrome\diabetes directly and actually may offer some protection against diabetes. High insulin levels seem the likely link between the two conditions.

Increased levels of Insulin Growth Factor-1 (IGF-1) has also been linked to vertex balding <ref>http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=10025745&query_hl=1&itool=pubmed_docsum</ref>

Increased incidence of androgenic alopecia has been linked to a high fat diet, the most notable example of which is the population of post WWII Japan, which saw its incidence of hair loss increase dramatically as its intake of fatty foods also increased (and height increased as well.)

Stress and androgen levels

Some types of stress can cause temporary decreases in plasma levels of sex hormone binding globulin (among other harmful responses.)

Evolutionary theories of male pattern baldness

Image:Male silverback Gorilla.JPG There is no consensus regarding the details of the evolution of male pattern 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. This is supported by the fact that the distribution of androgen receptors in the scalp differes between men and women, and older women or women with high androgen levels often exibit diffuse thinning of hair as opposed to male pattern baldness.

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.

Approaches to baldness

Psychological implications

Image:StoryMusgrave.jpg 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, Vin Diesel, Telly Savalas, Ben Kingsley, Patrick Stewart, Bruce Willis and politicians such as Abe Beame, who have been considered masculine and handsome in part because of their most obvious distinguishing feature.

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. Finasteride (marketed in the U.S. as Propecia) and minoxidil (marketed in the U.S. as Rogaine, and some places as Regaine) have shown some success in partially reversing loss. In a one one-year study of finesteride, evaluation after one year showed five of 21 subjects (23.8%) had two-grade improvement in MNHS grade on a modified Norwood/Hamilton scale and 12 of 21 subjects (57.1%) had one-grade improvement; the others remained at the same grade.[4] However such treatments are generally ineffective at treating extreme cases of hair loss. [5]

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 supplement 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.[6]

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 (Serenoa repens) is an herbal DHT inhibitor often claimed to be cheaper and have fewer side effects than finesteride and dutasteride. Unlike other 5alpha-reductase inhibitors, Serenoa repens induces its effects without interfering with the cellular capacity to secrete PSA. [7] Saw palmetto extract has been demonstrated to inhibit both isoforms of 5-alpha-reductase unlike finesteride which only inhibits the (predominant) type 2 isoenzyme of 5-alpha-reductase. [8] [9] [10]

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.

Concealing hair loss

Image:John d rockefeller.jpgOne 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.

Embracing baldness

Of course, instead of concealing hair loss, one may embrace it. A shaved head will grow stubble in the same manner and at the same rate as a shaved face. Many celebrities and athletes shave their heads. They spread the message of baldness by shaving the heads of adults to raise money for curing childhood cancer, which often causes children to lose their hair. Websites such as Curtis Bickham's Head-liner.com proclaims, "Let the Skin Proceed When the Hair Recedes", as a way of dealing with hairloss. See Head shaving.

Baldness folklore

There are many myths regarding the possible causes of baldness and its relationship with one's virility, intelligence, ethnicity, job, social class, wealth etc. While skepticism is warranted due to lack of scientific validation, some of these myths may have a degree of underlying truth.

• "You inherit baldness from your mother's father."

Research suggests that the gene for the androgen receptor, which is significant in determining probability for hair loss, is located on the X chromosome and so is always inherited from the mother's side.[[11]] There is a 50% chance that a person shares the same X chromosome as their maternal grandfather. Because women have two X chromosomes, they will have two copies of the androgen receptor gene while men only have one.

However research has also shown that a person with a balding father also has a significantly greater chance of experiencing hair loss. [12]]

Previously, early baldness of the androgenic type was thought to be autosomal dominant in males and to be autosomal recessive in females. The older model, in other words, could be written like this; the gene for baldness is a defect of some kind found on the X chromasome. Men only have one X chromasome, and women have two. If a person has one working copy of the gene in question,

• "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. While the notion that bald men are more intelligent may lack credibility in the modern world, in the ancient world if a person were bald it was likely that he had an adequate amount of fat in his diet. Thus, his mental development was probably not stunted by malnutrition during his crucial formative years, he was more likely to be wealthy, and also have had access to a formal education. Similarly, given the link between lack of exercise and metabolic syndrome, a sedentary lifestyle is less likely to corrolate with intelligence in the modern world.

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. Likewise, men with androgenic alopecia are more likely to have a higher baseline of free androgens. However there is no established correlation between hair loss and virility. However there are men with perfect hairlines and similar levels of androgens as well as men with hair loss who are voluntarily 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.

• "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 in the case of men, 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.

• 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 free testosterone levels may correlate with both hairloss and increased sex drive in predisposed individuals.

• A 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 vasodilator and is speculated to work, in part, by increasing blood flow to hair follicles, there is no evidence that standing on one's head can alleviate baldness.

• "Tight hats cause baldness."

This one probably started in the military where young men entering the service were required to wear hats and soon showed signs of going bald, or at least of hair thinning. This is due to coincidental timing. The age that young men enter the military is also the same age that male pattern hair loss begins. This is due to dihydrotestosterone, not hats. Hats do cause hair breakage and to a lessor degree to split ends.

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, due to reduced hormone levels.[13]
• 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. [14]
• The different predecessors of Old World and New World vultures convergently evolved a bald head, preventing feathers from retaining material from the vulture's diet of rotting meat, as well as helping in heat regulation.[15] [16]
• 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.The term "bald" derives from the English word balde, which means "white."

Reference

1. 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).
2. Rossi S (Ed.) (2004). Australian Medicines Handbook 2004. Adelaide: Australian Medicines Handbook. ISBN 0-9578521-4-2
3. Template:Note labelTemplate:1728

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See also

• Alopecia areata
• List of famous bald people

External links

• "Medical Treatments for Balding in Men," April 1999, American Family Physician (medical journal)
• North American Hair Research Society Frequently asked questions
• National Alopecia Areata foundation in http://www.alopeciaareata.com/default2.asp
• Alopecia areata index in http://www.keratin.com/ad/adindex.shtml
• Emedicine article on Alopecia areata
• Women's Hair Loss Support Resources
• The relationship between androgens and verbal memory

Consumer information pages

• [17] Nizoral and hair loss

Hair loss specialist directories

• Directory of Specialists by Region from the American Hair Loss Council

Male Pattern Baldness News

• Health Alternatives: zinc, silica, methylsulphonylmethane (MSM) and cod-liver oil, to slow down the process.
• What may be the markers of the male equivalent of polycystic ovary syndrome? Discusses androgenic alopecia and insulin resistance.
• The Pityrosporon yeasts. Their role as pathogens. Pubmed article on pathogenic yeasts which feed on sebum
• Topical application of ketoconazole stimulates hair growth in C3H/HeN mice. Pubmed article: Topical application of ketoconazole grows hair in C3H/HeN mice indicating that ketoconazole may be effective as a hair growth stimulant in people with seborrheic dermatitis.
• Vitamin D3 analogs stimulate hair growth in nude mice. Pubmed article: Vitamin D3 analogs dramatically stimulated the hair growth of nude mice indicating the role of vitamin D3 in hair growth
• Ketocazole as an adjunct to finasteride in the treatment of androgenetic alopecia in men.
• reductase inhibitors available, current 2006

The relationship between androgenic baldness, metabolism, diabetes and heart disease

• Androgenic effects of oral contraceptives: implications for patient compliance. Pubmed article on androgenic alopecia, contraceptives and women
• Established risk factors for coronary heart disease are unrelated to androgen-induced baldness in female-to-male transsexuals. Pubmed article: Male Pattern Baldness in Female to Male transsexuals receiving testosterone esters or testosterone undecanoate was not an indicator of increased risk for coronary heart disease.
• Male pattern baldness is not associated with established cardiovascular risk factors in the general population. Pubmed article: While male pattern baldness is associated with coronary heart disease, it is not correlated with abnormal height, weight, blood pressure, pulse rate, total and high-density lipoprotein cholesterol, or plasma fibrinogen indicating that male pattern baldness is linked to heart disease through some other mechanism.
• Early onset of androgenetic alopecia associated with early severe coronary heart disease: a population-based, case-control study. Pubmed article: Study indicates that early onset of androgenic alopecia is an indicator for coronary heart disease later in life.
• The risk of coronary heart disease in men with androgenetic alopecia. Pubmed article: 36 person study finds serum lipoprotein (a) and triglyceride levels, both risk factors for coronary heart disease, to be higher in men with male pattern baldness.
• Nitric oxide in the human hair follicle: constitutive and dihydrotestosterone-induced nitric oxide synthase expression and NO production in dermal papilla cells. DHT stimulates production of the free radical Nitrogen Monoide (NO) which in turn stimulates hair growth.
• Effects of triple antioxidant combination (vitamin E, vitamin C and alpha-lipoic acid) with insulin on lipid and cholesterol levels and fatty acid composition of brain tissue in experimental diabetic and non-diabetic rats. Pubmed article: Vitamin C + Vitamin E successfully lowered cholesterol levels.
• Lipid peroxidation and antioxidants in hyperlipidemia and hypertension. Pubmed article: Lower blood plasma levels of vitamins C and E correlate with higher cholesterol levels.
• Sex Hormone-Binding Globulin and Serum Testosterone are Inversely Associated with C-Reactive Protein Levels in Postmenopausal Women at High Risk for Cardiovascular Disease. Levels of Sex Hormone Binding Globulin and total testosterone were inversely associated with C reactive protein levels (believed to be a marker of chronic inflammation) among people not using hormone replacement therapy.
• Low Sex Hormone Binding Globulin is a potential marker for metabolic syndrome.
• Hormonal profile of men with premature balding. Pubmed article: A hormonal profile of men with premature balding. Balding men were found to have subnormal values of several hormones including; Sex hormone binding globulin(SHBG), testosterone and epitestosterone. Balding men were NOT found to have a lower free androgen index (i.e. they didn't have a lower level of bioavailable androgens in their blood.) A borderline significant trend was recorded with respect to increased levels in 17OH-P and prolactin.
• The relationship between serum levels of insulin and sex hormone-binding globulin in men: the effect of weight loss. Pubmed article: Sex hormone binding globulin levels are reduced by high levels of insulin.Template:Link FA

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