Hair, beautiful hair – hair care & baldness; includes related articles
Hair, Beautiful hair
On meeting someone, hair style and colour are often the salient features we notice, significantly influencing our first impression. Possibly because it resists decay after death, through the ages hair has come to symbolize love, strength and power.
Evolution provided most mammals with a thick coat of fur for protection against rain, cold and sun, for camouflage, and for sex appeal to ensure species propagation. Fine and transparent, human hair is a vestige of our hairier animal forbears, that probably evolved from the scales of reptiles. The adult human body averages five million hairs, of which 100,000 to 150,000 are on the scalp.
What is hair?
Odd though it may seem to call the tangle of inert protein arising from the scalp a “healthy head of hair”, our hair does reflect the overall state of the body’s health. The part of hair seen above the skin surface is a strand composed mostly of keratin — a tough, elastic protein which also makes up human fingernails, birds’ beaks and mammalian hooves. There are three basic types of human hair: lanugo — the very fine, transparent hair covering an unborn baby, shed by the seventh month of fetal development; vellus hair (from the Latin for “fleece” or “down”) — short, soft, sometimes pigmented hair covering the entire body except for the soles of the feet and the palms of the hands; and terminal hair — the coarse, pigmented, longer hair on the human scalp, face, armpit and pubic regions.
The hair shaft has three layers: the cuticle (outer protective layer), the cortex (providing strength) and the innermost medulla, which has no known function.
The cuticle, made of tightly overlapping layers of flattened cells, like slates on a roof or scales on a snake, encases the delicate cortex. If smooth and healthy, the cuticle gives hair gloss by keeping the scales non-porous and tight, preventing water loss. But the cuticle is easily damaged by heat, sun, dryness, salt water, harsh chemicals, or overtreatment (e.g., too much blow-drying, perming, or bleaching), which swells and lifts the scale, leaving the hair dry and brittle.
The cortex is made up of tiny keratin fibrils twisted together like yarn, which give hair strength, bounce and elasticity — largely determining the extent of its curl.
Since keratin, the main protein in hair, is colourless, hair colour comes from the pigment, melanin, secreted by melanocytes (pigment-producing cells) near the follicle base (SEE DIAGRAM). The more pigment granules there are, and the more tightly packed, the darker the hair. Two kinds of melanin contribute to hair colour. Eumelanin colours hair brown to black, and an iron-rich pigment, pheomelanin colours it yellow-blonde to red. Whether hair is mousy, brown, brunette or black depends on the type and amount of melanin and how densely it’s distributed within the hair. For example, deep-black African hair contains closely packed melanin in the cortex, a few in the cuticle. Very dark European hair, quite apart from having more melanin granules than lighter or blonde hair, has more melanin per granule. When the pigment-producing cells stop working hair loses its colour and turns grey.
Hair grows in cycles
The hair follicle goes through alternating anagen (growth) and telogen (resting) phases. A hair’s growth is finite, determined by heredity and the part of the body on which it’s growing. On a human scalp the growth phase lasts on average three to six, at most about eight, years. Given some 100,000 scalp hairs, their growth products about 100 feet of solid protein (keratin) each day — seven miles per year! Hair cells are among the body’s most rapidly-dividing cells.
Individuals who grow long hair have a long growth (anagen) period of six to eight years, although their hair may not grow faster than that of those with shorter growth periods. Since healthy scalp hair grows an average of half an inch or one centimetre per month, it might take two years to become shoulder length or six years for uncut female hair to reach the buttocks. With few exceptions, scalp hair rarely exceeds a maximum of two and a half feet in total length. On the eyebrows, the growing phase is only about 10 weeks, so eyebrow hairs never grow very long. Pubic and armpit hair growth rates are roughly similar, while leg hairs grow more slowly and are shorter. The growth or anagen phase of hair on male scalps is shorter than for females. In an adult scalp, after growing steadily for about three to six years, the hair stops growing and after a short, three- to four-week transition stage goes into its resting phase. After three months or so of resting, the same follicle begins to grow a new hair, pushing out the old one, which is eventually shed. A resting hair may stay put within its follicle for a few months, but as a fresh hair grows, the old one is showed out to make room for its successor. At any time, about 10 per cent of the hair on our heads is in the resting stage, easily shed, the rest (less easily tugged out) in the growing phase. Most of us naturally shed 50 to 100 scalp hairs a day.
Its glands, muscles and hormones
Hair is kept lubricated and shiny by sebum, and oily secretion produced by small sebaceous glands near the follicles. A dog can recognize a human being by the typical scent secreted by these glands. Clusters of tiny muscles, the arrector pili, surround and move the hair follicle. Male hormones or androgens regulate hair growth. Pubic and axillary (armpit) hair are particularly androgen-sensitive and grow at lower androgen levels than hair on the chest or legs. In boys, most pubic hair is grown by age 15, followed by the development of armpit hair two to three years later. In girls, too, an increase in androgens at puberty triggers growth of pubic and armpit hair. Scalp hair, not directly androgen-responsive, is influenced by local amounts of a testosterone derivative, dihydrotestosterone.
Hair loss worrisome to many
Progressive hair loss begins naturally in both sexes by about age 50, accelerating in the 70s and 80s. About 40 per cent of Caucasian men lose some hair by age 35. Hair shedding in males is often due to alopecia androgenetica — genetic/hormonal or “male pattern” balding. But even extensive hair-thinning rarely becomes obvious until 50 per cent of the scalp hair has been lost. Many events other than inherited balding can produce excessive hair sheeding, but only rarely do people lose more than half their hair for reasons other than male baldness. Hair may fall out because of over-tight hairstyles, some illness, or excessive hair colouring and curling. Hair shedding is often noted a few months after childbirth, following a prolonged fever, surgery, emotional upset, depression or some traumatic event. Sudden hair loss — all over the head — can also be provoked by crash diets; thyroid, pituitary or adrenal diseases; radiation or chemotherapy (for cancer); a fungal or other infection; burns; habitual tugging or compulsive hair-pulling, and exposure to certain chemicals and drugs. Except in male balding or unusual circumstances, hair lost through injury, illness or stress almost always grows back within a few months once the provocative agent is removed.
Inherited male baldness widespread and distressing
While baldness isn’t a disease, hardly any natural part of aging has been so widely regarded as abnormal and in desperate need of a cure. In the 20 centuries since Julius Caesar reportedly combed his fast-thinning hair over his bald spot, no effective cure for men’s balding heads has been discovered. For most men, including three million or so bald-domed Canadians, losing hair is a fate to be borne with dignity. However, two baldness remedies raise some hope of reversing this age-old complaint. The first is surgically transplanting hair plugs, the second a new lotion containing the drug minoxidil.
A receding hairline reflects age, but not necessarily great age, since some men start balding quite young. With the spurt in androgen secretion at puberty, the hairline moves back a little in 96 per cent of boys and 80 per cent of girls. Most boys continue to shed hair as they mature and, if baldness runs in the family, lose increasing amounts. By age 35 to 40, two thirds of Caucasian men are noticeably bald. There are several patterns of male-type baldness or androgenic alopecia. Usually it follows a characteristic design, starting with receding hair at the temples, often combined with a balding spot at the back of the head which gradually spreads, leaving a horseshoe-shaped fringe at the sides. The side fringe rarely disappears altogether. Male pattern balding goes in waves punctuated by periods of stability. The loss may begin at age 20, then stop, only to start up again a few years later. Since this type of baldness is largely hereditary, a man can usually, although not always, predict the extent of his future baldness by examining family portraits. About 50 per cent of children with a balding parent of either sex will inherit the dominant baldness gene.
The mechanism of balding
The rate of hair shedding in androgenic alopecia is speeded up by three forces: advancing age, an inherited tendency to bald early, and an over-abundance of the male hormone dihydrotestosterone within the hair follicle. The hormonal link in balding is complex. Eunuchs, who produce no testosterone, never go bald — even if carrying a baldness gene. However, if castrated men with a family history of baldness are given testosterone, they lose hair in the classic horseshoe-shaped pattern. Studies show that while balding men don’t have higher than average circulating testosterone levels, they do possess above-average amounts of a powerful testosterone derivative, dihydrotestosterone in the scalp follicles. In male balding, genetically primed follicles convert circulating testosterone to dihydrotestosterone, which successively diminishes or miniaturizes follicle size, producing ever weaker hairs. With a steadily shorter anagen growing cycle, more hairs are shed, the hairs becoming thinner and thinner until they are too fine to survive daily wear and tear. Balding hair gradually changes from long, thick, coarse, pigmented hair into fine, depigmented vellus sprouts.
Balding men seem to go to almost any lengths to regrow thinning hair. But experts stress that, until now, inherited balding in either sex has not responded well to any anti-balding stimulants, applications, injections, or other treatments. Specific foods or vitamins don’t regrow hair — although good nutrition is essential for healthy hair. A few hormonal remedies may work temporarily: systemic (oral) steroids induce hair regrowth for as long as they are taken, but the associated risks preclude their use; topical female hormones help balding women but feminize male bodies; spironolactone (Aldactone) may help a few.
Minoxidil of mixed promise for balding
The most effective medical baldness remedy to date — joint use of the drug minoxidil (used topically) with spironolactone (an anti-androgen, taken orally) — grows hair in some people. Adapted as a baldness remedy after years of use for treating high blood pressure, the advent of minoxidil was hailed by some as a “wonder” drug. The possibility of using minoxidil for baldness arose because almost all patients taking it for circulatory problems found hair growth increased all over their body, sometimes in embarrassing excess. When some enterprising researchers ground up minoxidil tablets, put them into a cream and applied it to balding scalps the result was hair regrowth in some. Subsequent studies confirmed that minoxidil (marketed as Regaine or Rogaine), applied every night in the right concentration (one to two per cent solutions), stimulates hair regrowth on some balding scalps. But less than 10 per cent of men achieved satisfactory results, and regrowth never exceeded an inch and a half. In about a third of the men who tried it, minoxidil produced a soft, downy fuzz, in the rest, no hair regrowth at all! All the regrown hair fell out as soon as minoxidil application ceased. After an initial burst of enthusiasm, minoxidil seems unlikely to improve the fate of most bald heads.
The disadvantages of minoxidil are its high cost (not covered by health insurance schemes as it’s considered a cosmetic); it only grows hair for as long as it’s applied; its success is unpredictable — only a few having good results; and it takes at least eight months of daily application to discover if one is among the lucky few whose hair will grow back in desirable amounts. Its side effects include local itching and prickling; headaches (in 40 per cent); dizzy spells or lightheadedness; and heartbeat irregularities. Although the drug appears to be safe when rubbed onto the scalp — since little is absorbed into the bloodstream — it is a vasodilator (expands blood vessels) and not recommended for anyone with heart disease. The long-term safety of minoxidil remains unknown.
Hair transplants one possible solution
Surgical hair transplantation (with scalp reduction) can be used for androgenic hair loss in men a|d women, ideal candidates being those with thick hair at the donor site (area from which hair is taken). Much like transplanted shrubs — roots and all — bits of growing, hair transplanted to the bald parts of the scalp may grow well.
Punch-graft surgery is performed in successive sessions, usually four months apart, but sometimes spread over years. The procedure is done by taking two to four millimetre “plugs” of hair-bearing scalp from the still-growing parts and transplanting them into small holes bored to receive them. It takes 250 to 400 plugs, with 10 to 15 hairs each, to fill a normally receding hairline. In each surgical session, only 75 to 100 plugs are transplanted so as not to compromise the scalp’s blood supply. The plugs are planted in neat rows, back to front according to a carefully designed hairline. Within a couple of weeks, all being well, the hairs on the transplanted graft fall out, but regrow in a few months. Post-operative complications are few: pain is controlled by painkillers, bleeding stopped by pressure and hair can be washed within about a week. It’s crucial to plant the plugs in the right direction, to avoid a messy look. If done incorrectly, the transplantee may end up with hair going in all directions, impossible to comb. One University of Toronto specialist recommends that those contemplating hair replacement should avoid being scalped by checking out the planned procedure beforehand. He suggests that transplant recipients should examine pictures of those already transplanted by their surgeon, before they decide on the procedure.
The main disadvantages of hair transplant surgery are that it’s time-consuming and expensive (costing $15 to $40 a plug for an average of 300 to 400 plugs); it provides a feathered appearance that never looks entirely natural; and the procedure doesn’t stop future balding.
Scalp reduction may precede hair transplantation — trimming out strips of balding scalp to reduce the total amount requiring hair grafts. It may be done several times, to remove all looseness and ensure a tight skin with the smallest possible area to be transplanted.
Other baldness solutions
Wigs made from artificial or, increasingly, real hair, kept in place by adhesives, are becoming more natural-looking.
Sutured hair pieces may be permanently stitched into the scalp, i.e., synthetic hair fibres or the real hair of others is permanently attached, sewn in or “shot” (like tiny barbs) into the bald scalp by non-medical technicians. Although claimed to be safe, it is not, because whenever a foreign object is permanently placed in the body there’s almost always a consequent infection or skin allergy.
Hair weaving, not to be confused with real hair grafting, is another permanent method of hair replacement, involving the tight stretching of flaps of a balding person’s own hair right across the head. Most specialists do not condone this practice because it prevents thorough cleansing of the scalp.
Women may also held
In women, baldness is often diffuse — diffuse alopecia — rather than “patterned”, with hair loss all over the head, rather than just at the top and centre. But it’s also usually inherited, with progressive diminution in follicle size, a shorter anagen phase, and increasingly fine hair. One Dutch study found that 27 per cent of women in their 30s and 64 per cent of those between 40 and 70 showed some balding. Hair thinning in women increases after the menopause when estrogen levels drop off, owing to excess androgens or other hormonal imbalances (e.g. due to ovarian cysts, Cushing’s syndrome — a disorder of the adrenal gland, pituitary or adrenal tumours) which increase the release of androgens. Other causes include birth control pills; certain drugs (e.g., danazol, cimetidine some beta blockers, retinoids, chemotherapy for cancer). Treatment for female balding includes estrogen therapy, cyproterone acetate, spironolactone, or minoxidil, and a new topical 0.025 per cent solution of the estrogen, estradiol, which may help prevent hair loss.
Too much as embarrassing as too little
Too much hair growing in the wrong places can be as distressing a cosmetic problem as balding, especially to women. Hirsutism (excessive hairiness), sometimes inherited, can arise from diseases involving over-production of androgens by the adrenal glands or ovaries. Excess hairiness in prepubescent children or during the menopause requires hospital investigation to rule out an underlying glandular disorder.
Several remedies are available for mild hair overgrowth. Dark hair can be bleached to make it less obvious. Or hair can be removed by plucking, shaving, or rubbing with an abrasive such as pumice stone, without making it grow back faster or more stubbly. Waxing — applying hot wax, allowing it to cool, harden and then stripping it off together with the hair — is best done by a trained cosmetician. Depilatories — chemicals that dissolve excess hair on contact — must be used with care in order not to irritate the skin. (It’s wise to test a small patch of skin first to check for sensitivity or allergy to the chemicals.) Electrolysis, the only permanent method of destroying hair follicies by an electric current, is a time-consuming procedure, which may cause temporary irritation. It leaves tiny, pit-like scars, and if incompletely done results in regrowth. Newer methods using high-frequency current (electrocoagulation) give good results and a skilled operator can destroy 100 hairs in half an hour.
Healthy hair is soft, not excessively greasy or dry, easy to brush, with good elasticity and bounce. It should be gently combed with a wide-toothed comb, and dried gradually at low heat. An occasional massage with the fingertips will enhance blood flow to the scalp. Since heat from curling irons and blow-dryers are notorious hair destroyers, to prevent damage, the hair should be dried on the lowest blow-dry setting and, if possible, left slightly damp.
A “good” shampoo leaves hair manageable, easy-to-comb and glossy. Most modern shampoos are synthetic detergents — replacements for the older types that dulled hair by depositing a scum on its surface. It is a myth that washing hair often makes it oilier. Whether dry or greasy, hair should be washed as often as required to look good (even every day). Most experts recommend at least once a week washing to prevent dandruff from clogging the scalp. Very dry hair may be improved by massaging with a little olive or almond oil, covering and leaving on overnight, washing out next morning. Despite the disparate claims of the countless products on the market, studies show little different between one shampoo and the next. Most contain the same basic ingredients with slightly more or less unnecessary extras (e.g., perfumes, fruit extracts, herbs). Many hair technologists recommend modern acidic preparations for all types of hair — as they don’t aggravate the scalp, which is normally acidic (with a pH of 4.5 to 5.5). Acidic products help to tighten the cuticle scales, keep in moisture and enhance shine. More alkaline types (with a higher pH) that claim to suit oily hair, may in fact swell the cuticle, bleach the colour, be too drying and overly harsh. Protein shampoos do not repair split ends, and although they may coat the hair shaft, making it smoother, they cannot “nourish” hair because their molecules are too large to enter the cortex.
Hair conditioners and body-givers
Most modern conditioners contain cationic quaternary ammonium compounds that provide a positive charge which reduces static and makes hair less “fly-away” and more manageable. Some products, particularly those containing benzalkonium chloride as the active ingredient, are good conditioners. Those with added polymers, collagen, balsam, silicones or resins that bond with and coat the hair shaft, may provide a protective film, smooth out the cuticle, reducing snarls and tangles. Conditioners that give “extra body” may contain waxes that, when dry, make it look fuller, some contain oil/fats (e.g., lanolin, mineral) to smooth hair, and a few have humectants that supposedly hold in water content. Price and exotic ingredients bear little or no relation to efficacy. Most conditioning products that claim to nourish hair do nothing of the sort as the ingredients cannot enter the hair unless they contain transformants — molecules small enough to pass into the cortex.
Altering the curl
Permanent waving rearranges the inner hair molecules, breaking and reforming its sulfur bonds, in a step-wise chemical process (that gives off the familiar sulfide odour which wafts off the head being permed). In perming, a gentle shampoo first strips off the sebum, then swelling agents open up the hair shaft — to allow entry of the bond-rearranging waving solution. Modern perming solutions (mostly ammonium or sodium sulfite) are more flexible than the former types, safer and more controllable. The latest acidic perming lotions, although more expensive, have the gentlest hair-reforming action, and are advised for use on fragile or tinted hair. Wound on rollers of varying sizes, hair gets a permanent curl of the desired type. The final extent of the wave depends on the kind of hair (finer curling faster), the time the solution stays on and the size of roller used. Finally the perming solution is rinsed off and a neutralizing agent or oxidizer put on to halt the curling process. The perming action must be stopped at the right time to avoid overprocessing. Modern perming solutions are often self-timed, the hair-altering reaction automatically halted after a designated time. A perm should never be done on hair dyed with metallic products and only with extreme care (using the gentler waving lotions) on hair that’s been recently bleached or tinted with permanent, oxidative dyes. Dual processing could disintegrate hair made porous by the tinting procedure. Perming after colouring hair requires great care and use of weaker waving lotions — a fact known by any trained hairdresser. Done by a reliable stylist, perming today is pretty safe.
Straightening hair uses the same basic ingredients and solutions as a perm, but is far harder on hair as it must be constantly pulled straight during the procedure.
Hair analysis not recommended
Medical experts strongly advise against the increasingly popular practice of hair analysis — measuring its mineral content — as a means of assessing nutritional status or detecting nutritional deficiencies. Although potentially useful as a research tool, experts consider hair analysis a highly unreliable, unstandardized technique of little or no clinical value. The chance of getting accurate information from a single hair strand is nil. The results are distorted by contamination from sweat, the shampoos, conditioners, sprays and colouring agents used to groom hair, and by the hair’s rate of growth. It’s highly questionable whether the metal or mineral content of a hair accurately reflects amounts elsewhere in the body.
COPYRIGHT 1988 Strategic Inc. Communications Ltd.
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