A while back it was universally agreed upon throughout the scientific community that dihydrotestosterone (DHT) is the cause of male/female pattern hair loss (androgenic alopecia; AGA), and it has remained that way ever since.
This has led to many treatments being developed that work to block DHT. Some of the most widely used and (what we claim to be) most effective treatments are those that target DHT such as finasteride and dutasteride.
But recently more and more people have been challenging the notion that DHT is the cause of AGA. Although, based on research, we can be reasonably certain that DHT likely contributes to hair loss, is it the sole cause?
There is evidence that it isn’t. There have been several other ways that people have proposed AGA works, two of which have a solid base of evidence supporting them.
In this article, we are going to explore how DHT, blood flow, and posture all might contribute to AGA and why you should be adamant to accept the conventional narrative that DHT is the only thing you need to worry about if you want to overcome hair loss.
DHT and hair loss
For starters, we have the obvious reason people believe AGA occurs: DHT.
DHT is a byproduct of testosterone, and both are what’s called androgens.
Androgens play an important role in the body as they are responsible for libido, bone density, voice change, facial and body hair growth, puberty and more in men and women.
DHT is created by an enzyme in the body called 5-alpha reductase (5-AR) which catalyzes the metabolic process responsible for turning testosterone into DHT. Once DHT has been produced, it goes throughout the body contributing to body and facial hair growth, maintenance of the prostate gland and seminal vesicles, and more. Scientists believe that in people who are genetically predisposed to hair loss, DHT goes beyond its role of sexual development and starts to wreak havoc on your hair.
Everyone’s hair has DHT receptors in it, but only people whose hair is sensitive to DHT are going to experience hair loss (1). Once DHT binds to the hair follicle it, in people who are sensitive, it starts the process of miniaturization. To understand miniaturization, you need to briefly understand the hair cycle.
The hair cycle consists of four phases: the anagen (growth), catagen (transition), telogen (resting), and exogen (shedding) phases. In healthy hair, the anagen phase will last anywhere from 3-5 years and the hair will grow between 18 and 30 inches. But, scientists believe that DHT sends a message to the body to begin shutting down the hair follicles, i.e. miniaturization.
Once miniaturization starts the anagen phase begins to shorten. As it gets shorter and shorter through each passing cycle, the hair will not grow and long or thick as it did in the previous cycle. Put two and two together and, yes, this eventually leads to thinning and/or balding.
There have been many studies done that confirm a correlation between DHT and hair loss, but why do medications like dutasteride that block 90+% of DHT (2) sometimes seemingly have no effect? Because there are other factors to consider.
Blood flow and hair loss
Many people believe that low blood flow is a result of hair loss, but it actually might be an underlying cause.
Red blood cells are responsible for carrying and delivering vital oxygen and nutrients throughout the body, including the hair. When your hair is receiving enough of these important compounds it will be able to complete healthy cycles, but if it isn’t: low blood flow and hair loss have been shown to be correlated in studies (3).
Whether low blood flow contributes to, or is the result of, hair loss scientists are still unsure, but we do know that it can worsen hair loss. This is because when your hair follicles are not receiving enough oxygen and nutrients it affects the hair cycles similarly to how DHT doesL the anagen phase of the hair cycle begins to shorten which eventually leads to thinning and/or balding.
This is why treatments such as minoxidil, LLLT, and more target blood flow: it has been shown that increasing blood flow will help regrow hair, but do we give low blood flow enough credit when it comes to hair loss? It isn’t quite clear.
Many people think of minoxidil as a secondary option to treatments like finasteride that work to block DHT. But, if DHT were the only underlying cause of hair loss, once you blocked it you wouldn’t need treatments like minoxidil. Scalp massages can help prove that blood flow may be an underlying cause of hair loss and may be just as important as DHT.
When preforming a scalp massage, the goal is to mechanically stimulate blood flow. Studies have shown (4,5) that daily scalp massages can boost blood flow and contribute to a faster growth rate and thicker hair. But, more important there is evidence (6) that scalp massages might affect AGA directly. Though this needs to be studied more in depth, the evidence that we have makes it pretty clear that low blood flow could be just as much an underlying cause of AGA as DHT.
Low blood flow is a perfect segway into the last potential contributing factor to AGA that we are going to talk about…
Poor posture and hair loss
Bet you didn’t see this one coming. Both DHT and blood flow are well known factors throughout the hair loss community, but poor posture is something that not a lot of people may have considered to be associated with hair loss.
Relatively speaking, poor posture and its connection to hair loss is a newer discovery. There are muscles in your neck that are connected to the top part of your scalp called the galea. It is theorized that when you have poor posture, it causes the neck muscles to be strained which pulls and tightens the galea.
Located just under the galea there is a layer of blood vessels that are connected to your hair follicles. When the galea is stretched, it can compress those blood vessels which subsequently lower blood flow (and we know what happens when there is low blood flow). It can also cause inflammation, which, since poor posture is a long-term condition, means that the inflammation associated with it is also long term. Inflammation has been shown (7) to cause calcification and fibrosis: two conditions that further inhibit blood flow.
Research on posture and hair loss is somewhat limited. But, there is one study (8) that confirmed is as a probable cause for hair loss, plus it makes sense from a human anatomy standpoint as well.
What is the main takeaway from this? Don’t rely on one treatment that does one thing to overcome hair loss.
As you can see, hair loss is a complicated phenomenon that we haven’t quite figured out yet. Since we have not yet developed a full-proof cure, it is best to challenge the conventional narrative that DHT is the only thing that causes hair loss. Look outside the box. By considering blood flow, poor posture, and anything else that research reveals as probably in the future as an underlying cause of your hair loss, you can give yourself a much better chance of understanding and overcoming it.