Male Pattern Baldness
Men have been suffering from androgenetic alopecia, otherwise known as male pattern baldness, since before the first coming of Christ. Julius Caesar was memorialized many times in stone with what was left of his hair combed forward, and a signature wreath covering his pate. Receding hairlines and bald spots plague men of every race, creed, and status. But why?
According to Bernard Arocha, M.D., president and owner of Arocha Hair Restoration, MPB occurs when a man has a genetic predisposition to sensitivity to the potent androgenic hormone called dihydrotestosterone (DHT). In most men, about 5% of their serum testosterone is converted to DHT by an enzyme called 5-alpha reductase. To those with the inherited sensitivity, DHT acts like a toxin on the hair follicles along the temples and mid-anterior scalp, undermining the absorption of nutrients and causing progressive miniaturization, which is when the growth phase of the follicles is shortened.
"There are 100,000 to 150,000 follicles on a full scalp," Arocha says, "all of which follow growth and rest phases. The growing (anagen) phase usually lasts about three to six years, during which time each hair matures in thickness and color. The resting (telogen) phase, when a hair ends its growth phase and falls out, lasts about 90 days. At any given time, only about 10% of follicles are in the resting phase, so normal hair loss is not noticeable." But for men with DHT sensitivity, over time, the growth phases of the follicles become so short that they grow only very fine, almost colorless hair (vellus hairs) until the miniaturization is complete and they produce none at all. Interestingly, the follicles around the ears and at the back of the head aren't affected by DHT, and MPB sufferers are left with a horseshoe pattern of hair.
More recently, researchers from the Perelman School of Medicine at the University of Pennsylvania have identified an abnormal amount of a lipid called prostaglandin D2 (PGD2) in the bald scalp of men with MPB. While the new findings haven't yielded any treatment, "it's a new piece of the puzzle," Kobren says. "We know that DHT is a major culprit, but maybe it's not only DHT that causes MPB." Scientists continue to look for other genetic and environmental factors to explain--and treat--baldness. Several groups are now looking at the relationship between the microscopic receptors that bind to Vitamin D in skin cells. "There's always interesting research being conducted," Kobren says. "It's always disappointing if the findings are ultimately inconclusive--but we keep hoping for a breakthrough."