Why you should NEVER drink water after spicy food

If you have ever eaten an unexpectedly hot curry, or bitten into a jalapeno, you may have felt that your mouth was on fire.

Now a video explains why - and it is down to a chemical compound called capsaicin specifically found in chili peppers.

The video reveals that the fiery ingredient binds to pain receptors on the tongue, and it explains why milk is more effective than water at easing the pain.

Capsaicin is a colourless, odourless substance that's most heavily concentrated around the tissue of a pepper, the American Chemical Society's YouTube video explained.

It binds to TRPV1 pain receptors found in the mouth that detect hot substances such as boiling water, as well as acidic or foods that could damage tissues.

When capsaicin binds to these receptors, they send neural signals to the brain, telling it we're eating something we shouldn't be.

This triggers responses such as tears or a runny nose, as well as a sense of heat to make us feel thirsty. These responses are designed to expel the substance from the body.

'The higher the amount of capsaicin in a pepper the more there is to bind to your TRPV1 receptors and the more intense your reaction is to that pepper,' the video said.

This intensity is measured on the 'scoville scale'.

When someone bites into a ghost pepper, for example - which is 400 times hotter than Tabasco sauce and is ranked as 1,000 scoville units - capsaicin binds to TRPV1 receptors all over their mouth, to make it feel like it is on fire.

It's normally recommended that over-zealous eaters drink milk to put out the 'flames' and this is down to molecules in the drink.

The video explains that capsaicin has an end with a long hydrocarbon tail, meaning it is considered a non-polar molecule and dissolves in other non-polar substances.

If a suffering diner drinks water – a polar substance – it is like mixing water and oil, so the water will spread the capsaicin around the mouth, intensifying the pain.

However, if they choose milk instead, the dairy product, containing non-polar molecules, will dissolve the capsaicin and wash it out of the mouth, giving them relief.

'In addition to their non-polar powers, dairy products contain the protein casein, which attracts capsaicin molecules,' the video continued.

'So milk or ice cream actively pulls the capsaicin molecules off your TRPV1 receptors and dissolves them,' perhaps giving diners an excuse to indulge in a cold desert after a hot curry or taco.

'There's good news for those of you who can barely handle the pain,' the video said.

The more capsaicin a person eats, the more tolerance they build.

This is because the TRPV1 receptors on the tongue become desensitised if spicy food is eaten regularly. 

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