Benquo

His estimate for total need is 10 to 60 grams per day, with a high end for people in poor health.

I had just written that glycine lowers core temperature.

What if those are connected?

Is fever what happens when you are too glycine depleted to fight infection through the more precise mechanisms glycine enables?

Heading.

Glycine helps us sleep by cooling the body.

The established explanation for glycine improving sleep is that it lowers core body temperature.

Glycine helps activate NMDA receptors in the brain's master circadian clock, the suprachiasmatic nucleus, or SCN.

This causes blood vessels near the skin to widen, dumping heat from the core to the surface.

The body needs its core temperature to drop in order to fall asleep, and glycine accelerates that drop.

In rats, surgically destroying the SCN eliminates glycine's sleep-promoting and temperature-lowering effects.

Glycine cleans our mitochondria as we sleep.

Your mitochondria produce energy, and as a by-product they generate reactive oxygen species, ROS, chemically aggressive molecules that damage proteins, lipids, and DNA.

ROS accumulate during wakefulness.

Amber Ohorones' 2024 paper Signals of Energy Availability in Sleep synthesizes the evidence that this accumulation is a key signal driving the need for sleep.

Wakefulness generates ROS, ROS buildup triggers sleep, and sleep clears them.

A Drosophila study tested multiple short-sleeping mutant lines with mutations in unrelated genes.

All were more vulnerable to oxidative stress than normal flies.

When the researchers forced normal flies to sleep more, those flies survived oxidative stress better.

And when they reduced ROS specifically in neurons, the flies slept less, as if the need for sleep had partly gone away.