Some people think it can.
So, this page investigates the
subject of hair hygiene and how, one way or another, it might impact on
both hair growth and hair loss.
This theory focuses on the overproduction of sebum.
Sebum is an oily substance produced and secreted by a sebaceous gland within each hair follicle.
And the amount of sebum produced is governed by dihydrotestosterone (DHT).
This powerful male hormone is the reason why sebum production increases during puberty, often causing greasy skin and spots to appear on teenage faces.
So, if the sebaceous glands within your scalp follicles are producing an excessive amount of sebum, and your hair washing is too infrequent, how might this be detrimental to the health of your hair?
Well, sebum can easily ooze down to the bottom of the hair follicles and fill them with oil.
So, if your hair washing regime isn't regular enough (i.e., every one or two days), it's possible that this sebum will then harden into a waxy plug and obstruct the hair shaft as it tries to grow along the follicle.
Also, if the hair root (dermal papilla) gets clogged up, hair production can start to choke, causing growth to slow down or even stop completely if the follicle becomes totally blocked.
That's the theory anyway!
However, there are plenty of people who don't shampoo that regularly, but still grow hair without any problems at all.
So, whilst some people claim that an extremely high level of hygiene is needed to maintain normal hair growth, this is simply not true.
Having said that, if your hair does get very greasy, it’s still probably a good idea to regularly keep it clean because it is possible that high levels of sebum might contribute to hair loss (by androgenetic alopecia) to some extent in this way.
So, that explains inadequate hair care, what about if you wash your hair too much?
Hair regeneration takes place through the hair growth cycle - this involves a growing phase (which usually lasts about five years), a breakdown phase (about two weeks) and a resting phase (three to four months) before the cycle restarts. And stem cells are vital if this ongoing process is to continue.
the picture below, notice the bulge area. This is where stem cells are
produced. And these stem cells must migrate down from here to the dermal
papilla for the next hair growth cycle to be successful (red arrow).
How then, do the stem cells get down from the bulge area to the dermal papilla?
In the picture, you can see that the sebaceous gland lies immediately above the bulge.
So, can sebum from the sebaceous gland help stem cells migrate down to the dermal papilla?
It does sound a bit unlikely that stem cells could somehow "piggyback" ride the sebum like this as it flows down to the dermal papilla.
But, sebaceous glands are present in all hair types we have (eyebrows, body hair, pubic hair, etc). And the position of the sebaceous gland just above the bulge also suggests that there might be a higher purpose to sebum in the role that it plays.
If so, then perhaps hair washing too often might remove an excessive amount of sebum from the hair follicles, which then becomes detrimental to the next hair growth cycle.
If, say, you wash your hair every single day with a strong* shampoo, perhaps over time, some follicles might actually be prevented from growing healthy hair follicles in subsequent growth cycles. And if your hair follicles are weak, so too will be the hair that they grow.
* Note: Many shampoos do contain strong ingredients, albeit in relatively small amounts. You can learn about dodgy shampoo ingredients by reading this page.
Some people believe that hair washing too frequently might be causing their hair loss.
This belief probably stems from the fact that hair loss is often most noticeable during the hair wash process (hair in the basin, clogging up the plughole, etc). And because you notice this, you assume that it's the hair wash process itself that is somehow to blame.
But, only weak hair that's ready to fall anyway will do so. So, when hair is wet and given a thorough clean, there’s bound to be more hair lost than during the rest of the day.
Finally, sebaceous glands and the sebum they produce are designed to help hair, not hinder it:
sebum will coat and condition the hair shaft (allowing it smooth passage as it grows along the follicle) and also provide it with a degree of waterproofing.
Clearly though, it’s important to get the balance right - wash your hair too much or too little and you could and end up harming your hair!
Note: Always consult with a doctor to identify which type of hair loss you have and how best to treat it.