Naked Science Forum

General Science => General Science => Topic started by: thedoc on 30/07/2010 11:43:00

Title: How does hair clean itself?
Post by: thedoc on 30/07/2010 11:43:00

Hello,

I have heard and read all over the place that hair cleans itself, but HOW does it do it?  That's my question.  I can't find it on the internet.  Every time I punch in: 'how does hair clean itself?', i get all these 'how to wash your hair without shampoo', etc. but that's not my question.

So, can you tell me please, exactly HOW does hair clean itself?

Thank you
Asked by Ransom


               

Go to the show page. (http://www.thenakedscientists.com/HTML/podcasts/show/2010.07.25/)

               

[chapter podcast=2746 track=10.07.25/Naked_Scientists_Show_10.07.25_6795.mp3](https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.thenakedscientists.com%2FHTML%2Ftypo3conf%2Fext%2Fnaksci_podcast%2Fgnome-settings-sound.gif&hash=f2b0d108dc173aeaa367f8db2e2171bd)  or Listen to the Answer[/chapter] or [download as MP3] (http://nakeddiscovery.com/downloads/split_individual/10.07.25/Naked_Scientists_Show_10.07.25_6795.mp3)

            

Title: How does hair clean itself?
Post by: Madidus_Scientia on 22/07/2010 11:35:39

I reject the premise!

Title: How does hair clean itself?
Post by: tangoblue on 22/07/2010 20:31:22

I dont think it does. if it did we wouldnt have to clean it would we.

Title: How does hair clean itself?
Post by: JnA on 22/07/2010 23:01:31

Hi.... human hair is not that great at staying clean. Mainly because it's scaly so dirt gets trapped. If you stop cleaning your hair (that included brushing) it will matt up (the premise behind dreadlocks). Having said that there seems to be a trend towards no shampoo hair these days.. but they all talk about good brushing, which is effectively cleaning.

In the animal world grooming takes place. I am not comepletly aware of all the different hair/fur structures, but I do know that an Orange Utan has fine fishing wire-like hair which means that the dirt just falls off it.. no scales.

Title: How does hair clean itself?
Post by: Geezer on 23/07/2010 00:04:06

Quote from: JnA on 22/07/2010 23:01:31

an Orange Utan has fine fishing wire-like hair which means that the dirt just falls off it.. no scales.

A barber once told my bother,

"Yur herr's like peen wire. The scissors just boonce aff."

Translating from the Scottish patois,

"Your hair is like the hardened steel wire they make pins from. My scissors can't cut it. They simply bounce off."

Title: How does hair clean itself?
Post by: LeeE on 23/07/2010 03:15:25

Afaik, hair isn't self-cleaning but, like our skin, it is self-regulating with respect to the oils that are secreted to stop them from drying out and becoming dry and brittle/flaky.

The no-shampoo trend stems from the idea that removing the naturally secreted oil, by washing, just stimulates our follicles and skin to produce more oil to replace it.  If the oil is constantly removed by excessive washing the follicles and skin end up over-producing their oils in an effort to redress what they see as an imbalance.  By not using shampoo, the hair retains much of the oil secreted by the follicles, so the follicles produce less oil and your hair ends up less oily/greasy than if you keep washing it.

There have been a number of fairly well publicised tests of this 'theory' and the results do seem to bear it out.  Similarly, there have been some tests with regard to washing your body with soap and the use of antiperspirants and antideodorants, which also seem to indicate that trying to fight your body's natural regulation systems just results in overstimulating them instead.

Part of the problem is that many people don't differentiate between the oils that should be on your hair and skin, and the dirt that shouldn't.  If your hair or skin is dirty then, you should use shampoo or soap to clean it, but if your hair or skin is not actually dirty then just washing with water should suffice.

Title: How does hair clean itself?
Post by: thedoc on 30/07/2010 11:43:00

We discussed this question on our  show

Ben - Now that’s a good question. I think he’s probably referring to the idea that if you stop washing your hair for six weeks or so, then it ends up sort of auto-cleaning and you end up with clean hair despite it not being washed. I think the truth is a little bit more complicated than that. It’s not that your hair is clean; it’s that your hair has the right amount of oils.

Normally, when you wash your hair with shampoo, it’s a detergent and it will strip the oils off your hair. Hair is supposed to be a bit oily so your hair follicles produce additional oil to make up for the oil that’s been washed away and you end up getting greasy hair. If you don't wash it away, there seems to be some kind of feedback mechanism that means that the follicles will produce the right amount of oil, and you won't end up with greasy hair.

Now I don't know if this really bears itself out in practice and from what I have seen and read about it, it seems to be much better for people with very short hair. It’s not that they never wash their hair, it’s just that they don't use soaps or shampoos – they just wash it with water. The water takes away the dirt and grime but the oils stay there to help protect the hair. Dave, you've got quite a lot of hair. How easy is it for you to manage?

Dave -  A while ago, purely in the spirit of scientific inquiry, and much to the annoyance of my then girlfriend, I decided to see what would happen if I didn’t wash my hair for three months. Basically, what happened is my hair sort of reached an equilibrium. It was much less greasy than it would be just before you'd wash your hair normally, but still greasier than just after it: a bit greasy, but not very greasy. So there does seem to be some kind of feedback loop. Also, interesting things happen when it rained because it appears that your natural grease from your hair is quite good at waterproofing because the outer layer got incredibly greasy and the rain would run off whilst the hair underneath would be entirely dry. So obviously, natural oils have advantages over conditioners.

Ben - That’s very strange. It's like wearing a natural shower cap made only of hair - that’s revolting.

Click to visit the show page for the podcast in which this question is answered. (http://www.thenakedscientists.com/HTML/podcasts/show/2010.07.25/) Alternatively, [chapter podcast=2746 track=10.07.25/Naked_Scientists_Show_10.07.25_6795.mp3](https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.thenakedscientists.com%2FHTML%2Ftypo3conf%2Fext%2Fnaksci_podcast%2Fgnome-settings-sound.gif&hash=f2b0d108dc173aeaa367f8db2e2171bd) listen to the answer now[/chapter] or [download as MP3] (http://nakeddiscovery.com/downloads/split_individual/10.07.25/Naked_Scientists_Show_10.07.25_6795.mp3)

Title: How does hair clean itself?
Post by: FuzzyUK on 04/08/2010 08:56:23

So if oils get washed out of hair, whats in hair conditioner that makes it nice and supple again?

Title: How does hair clean itself?
Post by: glorida on 16/08/2010 07:48:28

Its almost true for your hair (after leaving your hair for over 6 weeks without washing, just plain water will be able to clean it sufficiently) but not for your body.




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Title: How does hair clean itself?
Post by: cat_with_no_eyes on 18/08/2010 12:38:34

Hair is a very clever thing you see

Title: How does hair clean itself?
Post by: andrewbrak91 on 23/08/2010 10:43:03

- This thread is just superb !
Regards

Title: How does hair clean itself?
Post by: Charles8100 on 24/08/2010 10:30:53

- There have been more forums like this but this is what i loved.

Regards

Charles

Title: How does hair clean itself?
Post by: tangoblue on 12/10/2010 18:45:47

I dont think im going to not wash my hair for 6 weeks though :)

Title: None
Post by: Me on 22/02/2011 19:40:06

I can attest to the waterproofing but you forgot to mention it smells like a chippan!

Title: None
Post by: danielle vaughan on 17/10/2014 08:30:28

Everybody talks about greasy hair .i have never had greasy hair.quite the opposite.extremely dry. What will happpen to my hair if i dont wash im hoping it will be less dry

Title: None
Post by: Mardi on 30/03/2015 22:21:02

I haven't washed my hair with any but water, and occasionally lemon juice, for 7 years.  It took about 4 months to get past the initial gross greasy phase.  It's easier with long hair because you can tie it up and people don't really notice.  My hair and scalp are clean and healthy with no greasy look or smell.  Saves me time and $$

Title: None
Post by: Sharon adams on 21/09/2015 00:00:20

I left my hair for 3 months without washing it and afterwards it was just an absolute greasy mess. Did not work for me

Title: None
Post by: Shinz on 23/11/2016 02:19:07

how come not washing your hair works for some and not others?

Also its weird but I wake up with oily hair and sometimes in the day if Im not doing anything too much then the oil i less obvious???