Why the Pungency of Herbs Acts on the Body — The Compounds That Open the Cell''s Door

Why does ginger give a warming feeling in the body? Why is mint cool? Why does the tongue tingle when you chew pungent Sichuan pepper?

I want to make the point that these familiar sensations are not merely "taste" but a signal exchanged directly between the body's cells and a compound. And this is one of the several routes by which herbal medicine works in the body.

Cells have "doors"

Embedded in the membrane surrounding a cell are doors called ion channels. When such a door opens, ions like calcium move in and out of the cell, and that movement itself becomes a signal. A nerve "feeling" something, and a muscle responding, both begin with these doors opening and closing.

Among them is a group called TRP channels. These doors sense temperature and stimulus. Hot, cold, spicy, stinging — a considerable part of what we call sensation comes in through these doors.

And unexpectedly, the keys that open these doors are inside the very herbs we know.

The herb's compound fits into that door

When a compound fits precisely into such a door and makes it open and close, we say it acts as a ligand. It is like a key fitting into a lock. And this is not a metaphor but an actually confirmed binding.

Herb (compound)	Door it acts on	Weight of evidence
Ginger (gingerol, shogaol)	TRPV1 — binds at the same site as capsaicin from chili peppers	Established by structural and cell studies
Cinnamon (cinnamaldehyde), garlic (allicin)	TRPA1 — the door that senses stinging stimulus	Established by cell studies
Mint (menthol)	TRPM8 — the door that senses coolness	Established
Sichuan pepper (sancho, hwacho)	Both TRPA1 and TRPV1	Cell and animal studies

That ginger's pungent compound opens the door called TRPV1 at the same binding site, in the same way as chili's capsaicin has been revealed by studies that dug down to the structure of the channel. There is a molecular-level reason ginger feels "warming."

Here the "paradox of concentration" comes up again

There is a puzzling point. Such compounds in herbs are present in very small amounts. So how does the body respond?

The answer lies in the fact that the door itself is an amplifier. When a single key fits into an ion channel, countless ions pour in through that door. One signal swells greatly on the inside. So even a small amount is enough. This is the same principle I explained in another article as amplification by sensory receptors. (Why herbal medicine works — the paradox of concentration)

One compound touches several doors

There is another important thing. These compounds are not keys that open only one door. For instance, mint's menthol acts on TRPM8 and TRPA1, and camphor acts on TRPV1, TRPV3, and TRPA1 — that is, such compounds each touch several doors at once. It is as if one key fits several locks.

I see this as one layer of the way herbal medicine works in the body. One compound touches several doors, and a single dose of herbal medicine contains several such compounds. Rather than pressing hard on one spot, it touches several points a little at a time, all at once. (The account of the medicine waking up at a site turned acidic is another piece of the same picture too.)

So how do I use this — and where do I stop

At this point I will be careful.

That "ginger opens TRPV1" is an established fact. But to leap straight to "therefore ginger cures this disease" is an exaggeration. Between a compound binding to a cell's door and a person's disease improving there are several steps, and those steps differ by person and by condition.

What I can say goes this far: beneath the familiar taste and aroma of herbs lies a concrete molecular action that opens the cell's door. And I read this as one of the several routes by which herbal medicine works, and refer to it as one basis when designing a prescription. I do not assert beyond that.

And here too the principle is the same. If opening the door is the benefit, opening it too much is a burden. This is why a pungent compound is at once a stimulus and a medicine. (The benefit and harm of medicine emerge from the same place)

So, what you should not do after reading this article

Ginger, cinnamon, and mint are fine to enjoy as food. But please do not read this article as "so I should eat a lot of ginger." As I just said, if opening the door is the medicine, opening it too much is a burden. The same compound helps some people and irritates others. Taking a particular compound like a drug — in large amounts, for a long time, brewing it yourself — is not something I recommend. What to use and how much must be decided to match that person's condition.

To be honest with you

Let me distinguish where certainty ends and where my interpretation begins.

What is established: That the compounds of ginger, cinnamon, garlic, mint, and Sichuan pepper act as ligands on ion channels such as TRPV1, TRPA1, and TRPM8. That ginger's compound opens TRPV1 at the same site as capsaicin. That ion channels amplify signals. These are well confirmed by cell and structural studies.

What is at the experiment/cell stage: Much of the above binding has been confirmed in cells, test tubes, and animals. Whether the same thing happens on the same scale inside the human body, and within the complex combination that is a single dose of herbal medicine, is not yet settled.

What is my interpretation: The framework of "reading a compound touching several channels at once as one layer of herbal medicine's multilayer action." This is a perspective I have built in clinical practice, not something proven.

I try not to mix these three. Mixing them makes it sound plausible, but the plausible and the true are different.

Studies I referred to

• Review that herbal/plant-derived compounds modulate TRP ion channels: Herbal Compounds and Toxins Modulating TRP Channels, Current Neuropharmacology (2008). View original
• Structural evidence that ginger's pungent compound opens TRPV1 at the same site as capsaicin: Structural mechanisms underlying activation of TRPV1 channels by pungent compounds in gingers, British Journal of Pharmacology (2019). View original
• TRP channel pharmacology overall (capsaicin-TRPV1, menthol-TRPM8, allyl isothiocyanate-TRPA1): The pharmacology of TRP channels, British Journal of Pharmacology (2014). View original

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That ginger is warming and mint is cool is not a matter of imagination. It is because compounds actually open and close the cell's doors.

Herbal medicine does not work because it is mysterious. It works by opening and closing concrete doors like these one by one. I try to know those doors before I use it.