Glycine (abbreviated as Gly), also known as aminoacetic acid, is the simplest structure among amino acids.
Glycine was discovered in 1820 by French chemist Henri Braconnot. Glycine is as sweet as glucose and is an essential conditional amino acid for humans. Studies have shown that glycine has a very good regulatory effect on sleep, which is mainly reflected in the following aspects.
Inhibitory Neurotransmitter
Glycine has always been considered as the most important inhibitory neurotransmitter besides GABA (γ-aminobutyric acid). It is widely distributed in the central nervous system and plays a role in the transmission of nerve signals and participation in various physiological and pathological reactions. important basis. Glycine helps prevent epilepsy and treat bipolar depression, myasthenia gravis and other diseases. Most research suggests that glycine has a calming effect on the brain, which helps you relax and prepare for sleep.
Promotes sleep without altering sleep architecture
The researchers took 14 men as research subjects, asked them to take 3 grams of glycine within 1 hour before going to bed, and then measured the changes in their brain waves during sleep. It was found that these men fell into deep sleep faster and slept for a relatively longer time after taking glycine than when they did not take glycine. The researchers let 15 women troubled by insomnia take 3 grams of glycine before going to bed, and when they woke up the next morning, they all felt that they slept well and had a better effect on eliminating fatigue. Experiments show that: unlike traditional hypnotic drugs, glycine can shorten the time to fall asleep, stabilize the sleep state, and will not change the sleep structure.
lower core body temperature
How powerful is this tiny amino acid in regulating such a complex process as sleep? First, oral glycine easily enters the brain—it readily crosses the blood-brain barrier via glycine transporters. Once in the brain, glycine acts on NMDA receptors (known as N-methyl-D-aspartate receptors) in the suprachiasmatic nucleus (SCN).
By modulating NMDA receptors in the SCN, glycine induces systemic vasodilation and promotes a reduction in core body temperature. Temperature is just one of our body's 24-hour rhythms throughout the day, and as night approaches, the drop in temperature is important for initiating sleep. Glycine works on thermoregulation similar to common prescription sleep medications, which also promote sleep by lowering core body temperature.
Regulate daytime wakefulness
Glycine was found to be involved in another circadian process - stimulating the expression of arginine vasopressin (AVP) - a neuropeptide produced in the SCN. Animal experiments showed that in the glycine-treated group, the expression level of AVP increased during the day.
AVP signals synergistically with corticotropin-releasing hormone (CRH) to promote the release of adrenocorticotropin (ACTH), which ultimately triggers the production of adrenal cortisol, thereby promoting wakefulness.
Unlike other sleep aids, nutrients or medications, it promotes sleep but leaves you groggy the next day. Glycine actually corrects daytime fatigue and sleepiness. Upon waking, the sleep-restricted volunteers showed improvements in reaction time on tests of psychomotor alertness and reported feeling refreshed compared to the placebo group.
Dietary requirements
Glycine is an essential conditional amino acid in humans, with dietary requirements estimated at about 12 grams per day. There are many foods rich in glycine, such as spinach and broccoli, etc. We can ensure the intake of glycine by eating a balanced diet.
