Hair loss, also known as alopecia, is a common condition that can affect both men and women. The most common type of hair loss is androgenetic alopecia, also known as male or female pattern baldness. As the names suggest, genetics and hormones play a major role in causing this type of progressive hair thinning and baldness. In this article we talk about What Role Does Genetics Play in Male and Female Pattern Baldness?
In male and female pattern baldness, hair follicles shrink over time, producing shorter and finer strands of hair until the follicles stop producing hair completely. The hair loss follows a predictable pattern, with the hairline receding at the temples and vertex baldness developing (a bald spot on the crown of the head).
Genetics and Hormones in Male Pattern Baldness
Male pattern baldness, which affects around half of men by age 50, is strongly influenced by genetics and male sex hormones like testosterone and dihydrotestosterone (DHT). Researchers have identified over 200 genetic markers associated with male pattern baldness. The most important is a gene called the androgen receptor (AR) gene, which is activated by testosterone and DHT.
Men who develop male pattern baldness tend to have higher levels of DHT and greater numbers of androgen receptors in their scalp. The DHT binds to these receptors and triggers miniaturization of the hair follicles, making the hairs shrink over time. Men whose fathers experienced severe male pattern baldness tend to develop baldness earlier and more extensively.
The involvement of androgens explains why male pattern baldness does not occur in men who are unable to produce or respond to these hormones, such as men with complete androgen insensitivity syndrome. Castrated men also do not experience typical male pattern baldness unless they receive testosterone replacement therapy.
Genetics and Hormones in Female Pattern Baldness
Female pattern hair loss is also influenced by genetics and androgens like testosterone and DHT. However, compared to men, women produce only about a tenth as much testosterone and have much lower levels of DHT. Estrogen also opposes the miniaturizing effects of androgens in women.
This helps explain why female pattern baldness tends to be milder than male pattern baldness. Women typically experience thinning hair on the crown of the scalp with preservation of the frontal hairline. It often develops after menopause, when estrogen levels fall.
Researchers have identified variants in over 30 genes associated with female pattern baldness. As in men, the AR gene plays a role. Women with two copies of a common variant gene called AR-V9 tend to develop more extensive hair loss. This variant gene leads to higher activation of androgen receptors in the scalp by testosterone.
Other genes implicated in female pattern baldness influence sex hormone signaling pathways or hair follicle cycling. Some overlap with genes involved in male pattern baldness, while others appear specific to female pattern hair loss. A family history of baldness on either the mother’s or father’s side increases a woman’s risk.
Other Factors That Contribute to Hair Loss
While genetics load the gun, other factors often pull the trigger when it comes to male and female pattern baldness. Factors that can worsen genetic hair loss include:
– High stress levels. Stress causes scalp blood vessels to constrict, reducing nutrient supply to hair follicles. The stress hormone cortisol may also magnify the hair-miniaturizing effects of testosterone.
– Thyroid problems. Both overactive and underactive thyroid function can accelerate hair shedding and thinning. The thyroid regulates metabolism and hair follicle cycling.
– Nutrient deficiencies. Low iron, vitamin D, zinc, protein, and essential fatty acids can all contribute to excessive hair loss. These nutrients help hair follicles divide normally and grow strong hair shafts.
– Medications. Certain medicines used to treat high blood pressure, heart disease, arthritis, and more can cause excess hair shedding as a side effect. This type of hair loss is called telogen effluvium.
The good news is that only about half of women and men with genetic predispositions to pattern baldness will develop extensive hair loss. Lifestyle measures like stress reduction, improving nutrition, and exercise may help reduce hair loss linked to these trigger factors. Some treatments like minoxidil and finasteride can also slow genetic hair loss.
The Bottom Line
Androgens like testosterone and DHT bind to and activate hair follicle receptors called AR. People who inherit certain variants of the AR gene tend to develop more extensive pattern hair loss. While the mechanisms differ somewhat between men and women, this interaction between androgens and genetic susceptibility plays a major role in causing both male and female pattern baldness.
Lifestyle and environmental triggers often determine if a genetically susceptible man or woman will experience only mild hair thinning or more substantial baldness over their lifetime. Understanding the strong genetic component may help motivate people to start preventive measures earlier. Catching hair loss in the early stages provides the best chance to slow the progression of pattern baldness. I sincerely hope you find this “What Role Does Genetics Play in Male and Female Pattern Baldness?” article helpful.
