[epgui]

Biochemist who went to med school: very hot beverages will indeed cause tissue damage, and can cause oral cancer.

Though English uses the same word to describe both (“hot”), there is no relationship between “spicy” food and high temperature stuff, apart from the fact that they both stimulate pain receptors (but in very different ways, one being harmful and the other being harmless).

[dwringer]

The commentor above appeared to use the term in both ways, referring to both "hot spicy soup" and "burning hot coffee"

[epgui]

Yeah, and that struck me as really wrong.

[overthemoon]

Why does tissue damage increase the risk of cancer? My guess is that more damage -> more cells created to replace damaged ones -> more opportunities for mutation. Is that right? If you bite the inside of your lip a lot, is that bad? Uh, asking for a friend.

[Cerium]

When you have damaged tissue you must replace it sooner. Tissue replacement is by division of cells, which carries the risk of a transcription error. If the wrong error occurs and is not caught you have cancer.

[epgui]

Basically this, but perhaps a slightly more accurate explanation is that tissue damage causes inflammation, which is angiogenic, proliferative (which you hint at) and generally increases the risk of cancer.

[yamtaddle]

> If you bite the inside of your lip a lot, is that bad?

Yeah, um, gonna want an answer to that too.

This:

https://en.wikipedia.org/wiki/Morsicatio_buccarum

Makes no mention of cancer risk even in fairly extreme cases of cheek-biting.

The "Oral Cancer" article also doesn't list it as a risk factor or cause.

So... probably not that bad?

[epgui]

Yes, constantly biting your lip (I’m talking about injuring the tissue, not just nibbling) will increase your risk of oral cancer too.

It’s not something most people do super often, so I’m not sure if we’d even have a risk measurement for that. In almost all cases of accidental biting risk is basically nil / negligible… But theoretically nonzero.

A reference (somewhat taken at random) for more explanations of the general concept: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2803035/

It’s a well-established principle, and is one of the main reasons why smoking anything in general will cause lung cancer, why hepatitis frequently leads to liver cancer, why IBD frequently leads to bowel cancer, why alcohol consumption causes oral cancer, etc.

[wizofaus]

When you say harmful are you suggesting the pain receptors themselves are damaged by "spicy" substances? Is that why we develop increased tolerance? Though many people don't seem to, even after 40 or 50 years or eating spicy foods on an at least weekly basis.

[throwaway4PP]

Pain receptors that are activated by burning are indicating something harmful is occurring to your body not because the receptor is actually activated, but because of the cellular damage that triggers the receptor.

On the other hand, capsaicin doesn't activate pain receptors by cellular damage. It activates pain receptors by allowing a flood of (Na+? Ca2+?) ions through cellular walls. This triggers the pain receptors to fire without the cell damage. That is a laymen's description of reference [1].

It's interesting because the biochemistry of spicy foods differs by the 'spicy' compound. Capsaicin isn't the only one at play, wasabi and horseradish-containing foods have an entirely different molecule responsible for producing the spicy sensation, allyl isothiocyanate.[2] If you're a fan of spicy peppers and horseradish, you have definitely noticed the difference in how the 'heat' manifests: capsaicin-containing foods cause areas of damaged skin or mucus membranes to feel painful, usually localized in the mouth or around nail beds of those preparing the peppers.

Horseradish on the other hand, with it's spicy-ness provided by allyl isothiocyanate, produces a heat that - for me - is more located in the back of the head or in the upper sinus cavities. A completely different sensation than that of capsaicin.

Unfortunately, I don't know what the biochemical method of action is to produce those feelings. I'm sure it is buried deep in the literature, but it isn't on the wiki.

[1] https://en.wikipedia.org/wiki/Capsaicin#Mechanism_of_action

[2] https://en.wikipedia.org/wiki/Allyl_isothiocyanate

[epgui]

No, I said nothing of the sort. High temperatures are harmful, capsaicin is not.

[wizofaus]

Sure, it read a little ambiguously to me sorry.