The reserved door

The text of the episode

Welcome to Herba Barona, a food supplements shop in Paris. Every episode tells the story of a product we know badly, and you leave with one thing to remember. Today: ergothioneine.

Thousands of doors

On the surface of your cells there are doors. Thousands of doors. Each one is a transporter, a molecular lock that lets only one kind of passenger through: a door for glucose, a door for a given amino acid, a door for a given mineral. The body does not build doors for nothing — every lock is expensive, every entry has to be earned.

The riddle

And here is the riddle that occupied researchers for years: there is, in our cells, a dedicated door — a specific transporter, perfectly identified — whose almost exclusive passenger is… a molecule our body cannot make, that in theory it could do without, and that almost nobody has ever heard of.

That molecule is called ergothioneine.

Come from mushrooms

Discovered in nineteen hundred and nine in a fungus that parasitises rye — ergot, hence its name — it stayed in the shadows for over a century. Mushrooms are what make it, along with certain bacteria. We humans find a little of it on our plates: ceps, oyster mushrooms and shiitake are the best sources. And our body, rather than let it slip away, built that famous reserved door to capture it, bring it in and — a fascinating detail — concentrate it precisely in the tissues that work hardest and oxidise most: where the fire of oxygen burns strongest.

Stability out of the ordinary

You can see where I am going. This whole series has led us to the mitochondria, those power plants that tame oxygen — and that, in working, inevitably throw out sparks, the free radicals. Ergothioneine belongs to the antioxidant family, those spark-extinguishers. But with one feature that sets it apart from almost all the others: with stability out of the ordinary, it stays on duty for a very long time — where other antioxidants are used up and cleared within hours, it can remain in the body for weeks.

A rare molecule, one the body cannot make, that it actively captures through a door built on purpose, that it routes towards its zones of fire, and that it holds on to carefully. When biology goes to that much trouble for a single passenger, researchers tend to take the question seriously — and that is exactly what is happening: ergothioneine is today one of the most studied molecules in the world of antioxidants.

One last image

One last image for the road. Among the thousands of doors on your cells, there is one, built millions of years ago, that is waiting for a single visitor. A visitor come from mushrooms.

Great stories sometimes hang on a lock.

That was an episode of the Herba Barona podcast, recorded in Paris. See you soon.