Many years back, when my mother told me that I should avoid hot water shower, I just ignored her free-advice. She tried telling me it’s not good for skin and hair. And this explanation was not good enough for me.
I mean, I was a student of science, and I needed more than ‘not good for me’. In hindsight, it’s my bad that I didn’t take her advice seriously. And to recall my skin woes, I use to use endless amounts of skin moisturisers in vain, and they wouldn’t quench the skin dryness. I wondered why then.
Also, my hair didn’t look pretty either.
There was hair loss, and it was dull and sad. Of course, time to time oiling and aloe vera hair masks saved it from total misery. But the oomph and gorgeous factor was missing from my hair.
One thing I have learned in these years is yes modern science puts things in perspective, but never ignore traditional advice and wisdom from elders. They may not have the fancy words to articulate the knowledge, but perhaps they are trying to convey some priceless message.
Okay, that’s my learning. Now let’s get back to the topic, why hot water shower can cause hair loss and thinning. Fortunately, I have a technical explanation for you, so you don’t ignore what I have to say.
A hot shower can feel soothing and relaxing. However, it’s not worth it because it robs your scalp of moisture and natural oils, disrupts pH balance and leads to rash and hair thinning. So there’s more than one reason to turn the temperature dial down. Let’s dig deeper, shall we…
Just below the scalp lie oil glands, and they secrete sebum (our hair’s natural oils). Their job is to protect and moisturise the scalp skin. And hot water is not very friendly for these oils. Along with the shampoo that you apply, it strips the sebum and makes your scalp dry and dehydrated.
If you have suffered from dryness, you know what that means – itching and flaking. And both – itching and flaking – is terrible for the health of your scalp. It can disturb the hair roots and may trigger inflammation. As a result more itching and flaking follows. So, there starts a vicious cycle.
You might think that by putting a conditioner or plant oil you can solve the problem of dryness, but it’s not as simple as replenishing the oils. That brings us to point no. 2
If you have heard the term pH balance a million times but do not know what it means, let me put it simply. pH measures how acidic or alkaline a solution is. It’s measured on a scale of 1 to 14. Where a pH of 7 is neutral, a pH less than 7 is acidic, and a pH greater than 7 is alkaline or basic. Pure water has a pH of 7, which means it’s neutral, so neither acidic nor alkaline.
Any idea what the pH of our scalp it?
Well, it’s around 5 – which means it’s slightly acidic. And what gives our scalp the acidic pH? It’s the sweaty combination. When our scalp’s natural oils combine with sweat, they create an acid mantle. This acid mantle forms a thin film over our scalp and hair and gives them an acidic pH.
But why is pH balance a big deal?
Because it protects our scalp from fungus, bacteria and other microbes. Also, when pH is at optimal levels, it improves the skin’s barrier function, so our scalp is able to retain moisture better and flake less.
As the hot water washes away all the sebum, off goes the protective acid mantle. And with it gone, our scalp is more prone to getting infections as well as eczema, dermatitis and acne. That’s not very nice, right? With scalp in a mess, the hair follicles cannot thrive and flourish. This can slow hair growth.
While your scalp will secrete more sebum and form the pH balance again, but it takes hours to replace it and the gap time leaves the scalp unprotected and exposed. Besides, hot water can also impact the hair directly, which brings us to the last point….
I mean water may seem harmless, but when your hair gets wet, it swells. And the swelling causes the hair cuticle- which is the outermost layer of hair to open up. Cuticles consist of overlapping cells that look like fish scales or shingles on the roof. Most of the time, they remain tightly sealed and work to protect the inside of the hair as well as keep the hair smooth and shiny.
Washing hair with hot water makes the hair swell much more and cuticles to open wider than when you wash hair with warm or cool water. And that causes the leakage of lovely oils and proteins from the inside of the hair. And since protein is what keeps our hair strong and healthy, losing them on a constant basis will make hair thin and damaged.
Also, as cuticles open more in response to hot water, they are more prone to getting chipped off while shampooing. In the long run, this creates weak spot and uneven surfaces on hair. The result is tangles, frizz and dull hair that can break easily. Ouch…
So yes, washing hair with hot water has a list of disadvantages and the only plus point maybe a couple of minutes of relaxation. But it means an irritated scalp and dull, thinning hair.
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