Sunday, 9 May 2010

Peppermint oil - for itchy scalps, fungus and bacteria!

*Updated 22:00 to include number 4*

Jam_Noire asks,' I know people who use peppermint oil in their hair to reduce itchy/dry scalp. Can you discuss this?'

Peppermint oil is known to contain menthol (the pretty crystals to the right) which is responsible for many of its active effects. Here is the research I found:

1. Anti itching effect
Menthol is recognised by the FDA as an anti-itching agent (itching in medicine is known as pruritus). The concentration required is around 1.5% (Fed Regist, 72(43):9849-52, 2007). It is not approved or effective as a dandruff medication however.It is effective in alleviating itchiness.

2. Cooling effect
The tingling and cooling effect associated with peppermint oil happens because menthol stimulates the same nerves that react to cold (these nerves are actually identified by scientists as menthol receptors). (Nature, pp 204-208, 2007 and Cell, pp. 705–715, 2002). It is called a cooling sensation because while the area feels cool, it is actually not being cooled at all.

3. Aromatherapy and brain effect
There are quite a few books describing aromatherapy related effects of peppermint oil and menthol. I have not quoted any because I did not see scientific research in these texts.

I did however find that using shampoo with menthol has been shown to increase some aspects brain activity (The double effect of l-menthol on the brain activity, Yoshida et al, CABI abstracts). Interesting non?

4. Antibacterial and Antifungal effect
Menthol has antibacterial and antifungal properties. In this particular article, the authors reviewed and quoted several papers which indicated that indeed menthol can kill several types of bacteria and fungi (Journal of the American Academy of Dermatology, pp 873-878,2007)   

Are you a fan of peppermint oil? If so, how do you use it?

10 comments:

  1. According to Paula Begoun, menthol is an irritant like many others hence you do not want to use it on your skin.

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  2. Unfortunately Paula does not tell the whole story. Menthol is FDA approved in part because it has a very low level of irritancy. Manufacturers report complaints anywhere between 1 in 310,000 to 1 in 950,000 people.

    Excluding people who are allergic (where any amount of menthol can be irritating or harmful), low levels of menthol are not associated with adverse effects. Low means 16% or less.

    High concentrations (around 40%) can actually cause redness and burns.

    In short the irritancy of menthol is relative to the concentration used and the person (i.e allergic or not). All the figures I have quoted in this comment come from the reference in number 4 (Journal of the American Academy of dermatology).

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  3. I use peppermint oil on my 21 month old's dry, itchy scalp and my own, she has a more sensitive scalp than I and she has had no irritation from it. The smell is soothing I use it in some of my shea mixes for smell and its supposed use to stimulate the hair follicles to increase hair growth. My main purpose for me is more for smell and its relaxing aroma. :-) Too much though and you'll have just wind up with a headache LOL

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  4. I used to use peppermint oil with shampoo. Hmm. Maybe I'll go back it for the increased brain activity. :o) Thanks for sharing!

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  5. I use peppermint in my hair spritz and I also rub a little in my hands when my nose is stuffed up. It helps to open up the passages.

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  6. I'm not an expert and i'm happy to have this double checked.
    I found a quote from her book online and i have her source.

    ''Even if your skin doesn't feel or appear irritated after exposure to those things, it is still being irritated and the skin breakdown is nonetheless taking place''....(source: skin research and technology, Nov 2001 p227-237 )

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  7. Thank you for the reference Kadiane, I like references!!

    I have checked it out. The reference quoted does not refer to menthol at all. In fact it refers to normal skin, sun exposed skin,heat rash, diaper rash and SLS treated skin. It discusses the appearance of chemicals that we secrete in response to inflammation...saying that even when there is no visible sign of inflammation (like redness or heat on the skin), it may still be happening.

    There is no reference to menthol or peppermint at all anywhere in the document. I also think that the statement used 'skin breakdown is nonetheless taking place' is a bit of an exaggeration.

    Here is the summary of methods quoted directly from the paper (Sebutape is a commercial tape that is supposed to be better than using selotape which was the old way of collecting sebum or anything else on the skin)

    Methods: In clinical studies, Sebutape was applied to normal appearing uncompromised skin, as well as to compromised (diaper or heat rash), chemically treated (sodium laurel sulfate), or sun-exposed skin. Sebutape was applied to the skin for a 1 min collection interval. Tapes were extracted in saline using a 10 min sonication, and the extracts were analyzed for human interleukin-1a (IL-1a), IL-1 receptor antagonist (IL-1RA) and IL-8 using
    commercial immunoassay test kits. The cytokine levels recovered from each tape extract were normalized to total protein (TP)
    levels. In infant product use tests, the severity of skin irritation (diaper and heat rash or erythema) was also assessed using a
    visual grading scale.

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  8. Thanks JC. By ''Those things, she meant the list of things she gave prior to that sentence. It included sun exposure. After that sentence, she went on to remind us how we do not feel the effect of su exposure and then she gave the source. The way she said it i would have though the source was to explain the breakdown we do not feel. I mean she has a chapter on sun exposure. Why give another sun exposure reference when it is about all kind of irritant. I kind of feel betrayed as if she was purposely not giving us the info cuz she has no proof. A lot of product have a bad review in her book JUST because it has menthol in it. I'll check her latests book and see if she has more recent references but is seems like on her web site she sticks to her no menthol version. And why is it that nobody is standing up to her? The beauty brain and others ? Grrrrrrr !!

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  9. I put peppermint oil in my cowash conditioner so that I can get some extra cleansing effects.

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  10. Nice! I'll be buying some peppermint EO. I'll add it to my ACV &/or tea rinses and my coconut oil treatments. I love taking care of my hair with things that are proven effective!

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