Hair loss in men, or androgenetic alopecia, is the most common type of hair loss in men.
Hair loss affects about half of men over 50 and about 50 million men in the United States.
DHT has also been associated with hair loss in women, but this article will focus on male pattern baldness.
What is DHT?
DHT has several roles. In addition to hair production, it is linked to benign prostatic hypertrophy or enlarged prostate and prostate cancer.
DHT is a sex steroid, which means it is produced in the gonads. It is also an androgen hormone.
Androgens are responsible for the biological characteristics of men, including a deeper voice, hair and increased muscle mass. During fetal development, DHT plays a vital role in penile and prostate development.
In men, the 5-alpha reductase (5-AR) enzyme converts testosterone into DHT in the testes and prostate. Up to 10% of testosterone is normally converted to DHT.
DHT is more powerful than testosterone. It adheres to the same testosterone sites, but more easily. Once there, it stays attached longer.
Growth and loss of hair.
Hair loss in men is the most common type of hair loss in men. The hairs of the temples and the hood slowly thin and eventually disappear.
The exact reason for this is unknown, but it is believed that genetic, hormonal and environmental factors play an important role. DHT is considered an important factor.
Three phases of hair growth
To understand hair loss in men, we must understand hair growth.
Hair growth is divided into three phases: anagen, catagen and telogen:
Anagen is the growth phase. The hair remains in this phase from 2 to 6 years. More hair is hard. Normally, about 80-85% of the hair in the head is in this phase.
Catagen lasts only 2 weeks. It allows the hair follicle to renew itself.
Telogen this is the last of the three.
Hair loss occurs in men when the follicles are slowly miniaturized, the anagen phase is reduced and the telogen phase lengthens.
The shorter growth phase means that the hair cannot grow as before.
Over time, the anagen phase becomes so short that the new hair does not shine even through the surface of the skin. The growth of telogen hair is less anchored in the scalp, which facilitates the fall.
As the follicles become smaller, the hair shaft becomes finer at each growth cycle. Finally, the hairs are reduced in hair, the kind of soft and clear hairs that cover a child and disappear especially during puberty in response to androgens.
Users of anabolic steroids, including bodybuilders, have higher levels of DHT. However, they often suffer from hair loss.
Hair on the head grows without DHT, but underarm hair, pubic hair and beard hair can not grow without androgen.
People who have been neutered or with a 5-AR deficiency have no experience of male pattern baldness, but they also have very few hairs on other parts of the body.
For reasons that are not well understood, DHT is essential for the growth of most hair, but compromises hair growth on the head.
It is believed that DHT adheres to androgen receptors in hair follicles. With an unknown mechanism, it seems to activate the receivers to start miniaturization.
In 1998, researchers found that the selected follicles and the skin of a bald scalp contained higher levels of androgen receptors than those of a scalp without baldness.
Some scientists believe that some people have a genetically transmissible sensitivity to normal levels of circulating androgens, particularly DHT. This combination of hormonal and genetic factors could explain why some people are more likely than others to lose their hair.
Other causes of hair loss
Another theory proposed to explain hair loss in men is that with age, follicles are subjected to increasing pressure on the scalp.
In younger people, the follicles are moistened by the surrounding adipose tissue located under the skin. Young skin is also better to stay hydrated. As the skin becomes dehydrated, the scalp compresses the follicles and makes them smaller.
Testosterone also contributes to the reduction of adipose tissue. As a result, higher testosterone levels can further reduce the scalp’s ability to cradle the hair follicles.
Some scientists suggest that when the follicles try to maintain their condition, the extra enzymatic activity occurs at the site. More testosterone is converted into DHT, resulting in more erosion and more hair loss.
A more in-depth study of DHT and hair loss in men may one day allow scientists to decipher the male pattern of baldness. For now, it’s a waiting game.