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Author Topic: Why does curry burn your bum?  (Read 61469 times)

Offline John Chapman

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Why does curry burn your bum?
« on: 07/02/2009 22:25:59 »
I understand, more or less, why spicy food feels hot in the mouth. I know it has something to do with capsicum stimulating heat receptors on your tongue. And following one occasion when I sneezed while eating chili I can confirm that it has the same effect on olfactory tissue. Ouch.

But why does it burn so much the next morning on it's way out? After all it doesn't burn other tissue. I've never heard of having to rinse it off your hands before it burns them or having to wear safety goggles whilst cooking it to protect your eyes. And it passes by my sphincter so briefly and yet it burns.

By the way, for our American friends, 'bum' means 'fanny'. In the UK 'fanny' means another even more sensitive part of the body!


 

Offline chris

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Why does curry burn your bum?
« Reply #1 on: 07/02/2009 23:20:21 »
Hello John.

The hot chemical in chilli is capsaicin. This is an oily molecule that provokes pain by locking onto a class of small calibre nerve endings called C fibres, which bear a specific capsaicin "receptor" - this is effectively a molecular docking station to which capsaicin molecules can bind. When this receptor engages with capsaicin it opens a pore in the nerve cell membrane, activating the nerve and triggering impulses (action potentials) which are interpreted as pain.

The same nerve endings also convey noxious temperature (heat) sensations, which is why the pain triggered by chilli is experienced as a burning heat.

In order to experience the burn the capsaicin molecule must come into contact with appropriate nerve fibres bearing capsaicin receptors. Skin is relatively resistant to the effect because it is a thickened stratified squamous epithelium mainly composed of many layers of dead skin cells. The capsaicin therefore finds it difficult to penetrate the layers to reach vulnerable nerve fibres.

However, at sites where the mucous membranes are thinner there is a much-reduced barrier to the penetration of the molecule through the tissue and onto the nerve fibres. As a result mouth, eyes, nose, genitals and injured skin are much more susceptible, because the mucous membranes here are much more delicate than coarse body skin.

When you eat curry you therefore experience the burn as the capsaicin binds to receptors in your mouth, but the rest of the GI tract (oesophagus to rectum) are not endowed with the receptors for capsaicin (at least in appreciable quantities) and hence you do not experience burning as the hot meal makes its way through you.

Capsaicin is also not broken down (at least completely) by digestion and hence what exits later can still contain a reasonable amount of the chemical. And where the lining of the GI tract gives way to normal skin again, at the anus, there are large numbers of capsaicin receptors. As a result you have the killer combination of a sensitive mucosal surface "seeing" a reasonable does of capsaicin, so you get ring sting.

Thankfully the effect is usually mitigated by the fact that the material often spends very little time in contact with that tissue - at least going on my recent curry experiences...

I hope that helps!

Chris
 

Offline John Chapman

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Why does curry burn your bum?
« Reply #2 on: 07/02/2009 23:31:30 »
Thanks Chris. That was amazingly informative.

Wow everyone. I've had an answer from Chris. I've been touched by a science God. [Runs shrieking around the room waving arms like an excited girlie at a Beatles concert]
 

Offline DoctorBeaver

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Why does curry burn your bum?
« Reply #3 on: 20/02/2009 23:30:11 »
Why would evolution have put those receptors round the anus?
 

Offline Karen W.

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Why does curry burn your bum?
« Reply #4 on: 20/02/2009 23:41:31 »
I understand, more or less, why spicy food feels hot in the mouth. I know it has something to do with capsicum stimulating heat receptors on your tongue. And following one occasion when I sneezed while eating chili I can confirm that it has the same effect on olfactory tissue. Ouch.

But why does it burn so much the next morning on it's way out? After all it doesn't burn other tissue. I've never heard of having to rinse it off your hands before it burns them or having to wear safety goggles whilst cooking it to protect your eyes. And it passes by my sphincter so briefly and yet it burns.

By the way, for our American friends, 'bum' means 'fanny'. In the UK 'fanny' means another even more sensitive part of the body!


Well I am positive that it DOES burn other tissue.. around and in the eyes and private places when your partner has neglected to wash the hot stuff off his hands before sexual encounters.. Pardon my bluntness.. but it is extremely uncomfortable and highly painful! So always exercise the lovely art of hand washing after handling or cutting!

It also leaves serious red whelps across the lips of small children.. my Daughter pulled a fork out of a jar of Jalapeno peppers and then inserted the fork into her mouth and pulled it across her little lips.. It was horrible huge raised whelps that mimicked the tongs of the fork across her lips and down her chin.. extremely painful screams followed by breathing difficulty because it took her breath away... Horrible, Horrible....
 

Offline Don_1

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Why does curry burn your bum?
« Reply #5 on: 21/02/2009 11:17:45 »
Why would evolution have put those receptors round the anus?

To make us sorry for being a pig the previous day?
 

Offline Chemistry4me

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Why does curry burn your bum?
« Reply #6 on: 21/02/2009 11:28:28 »
I've never noticed this ???
 

Offline Chemistry4me

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Why does curry burn your bum?
« Reply #7 on: 21/02/2009 11:29:02 »
Should I conduct some emperical study? :)
 

Offline Don_1

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Why does curry burn your bum?
« Reply #8 on: 21/02/2009 11:50:02 »
It's not called 'Vindaloo' for nothing!
 

Offline John Chapman

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Why does curry burn your bum?
« Reply #9 on: 21/02/2009 14:21:28 »
Tut tut. Oh Chem4me! Oh deary, deary me! You've done it now.

I've never noticed this ???

You realise what we are all thinking now?

"Chem4me is one of those wimpy 'I never eat anything stronger than a korma' guys. Whereas I'm tough enough to eat a vindaloo with extra lime pickle and a napalm dip. And I've probably got a bigger willy. And I bet he drinks babycham!"

 ;)
« Last Edit: 21/02/2009 15:47:43 by John Chapman »
 

Offline DoctorBeaver

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Why does curry burn your bum?
« Reply #10 on: 21/02/2009 16:44:38 »
And I've probably got a bigger willy.

 ;)

 

Offline Chemistry4me

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Why does curry burn your bum?
« Reply #11 on: 21/02/2009 22:21:40 »


 

Offline John Chapman

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Why does curry burn your bum?
« Reply #12 on: 21/02/2009 23:28:59 »
Ha ha. Where do you get all these unusual emoticons?
 

Offline DoctorBeaver

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Why does curry burn your bum?
« Reply #13 on: 21/02/2009 23:37:17 »
 

Offline John Chapman

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Why does curry burn your bum?
« Reply #14 on: 21/02/2009 23:45:51 »
 

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