How to Spot a Psychopath

A reader writes:

When I eat cheese, I sweat. I don't really feel hot, I just break out in a sweat.

Sweating when you eat a curry, that I understand. Or a big hot dinner; that could actually physically heat you up. But cheese? WTF?

Don

There's a compound in aged cheese, tyramine, that induces the release of epinephrine (a.k.a. adrenaline), and some related neurotransmitters. The result is a sort of mini-fight-or-flight reaction, including a faster heartbeat and, as you say, sweating.

Tyramine affects different people differently; many people don't notice the effect at all. I think the effect can vary from day to day and depending on how much cheese you've eaten. It does for me, anyway; sometimes vintage cheddar gives me a cheese-sweat, sometimes it doesn't.

Speaking of which, the type of cheese definitely matters. Un-aged cheeses, like cream cheese or cottage cheese or Kraft Reprocessed 580-Nanometer Partially Homologated Polymer Dairy Analogue, contain very little tyramine. As a general rule, the stronger-flavoured the cheese, the more tyramine there'll be.

It's the tyramine, by the way, that makes it a bad idea to consume vintage cheese if you're also taking a monoamine oxidase inhibitor drug. Old-style "irreversible" MAOIs plot to kill you in a few different ways, one of which is giving you a massive blood-pressure spike if, in cheerful defiance of the common sense of more than half of the world's population, you eat something which used to be milk, but has been left to sit for years on end and is now a stinking mould-covered lump of obviously lethal putrescence.

Psycho Science is a regular feature here. Ask me your science questions, and I'll answer them. Probably.

And then commenters will, I hope, correct at least the most obvious flaws in my answer.