Glycine is a supplement in your local health food store that may help with sleep. On the bottle it usually say to take on empty stomach before bed. This is because glycine is an amino acid. Amino acids are usually more effective when taken on an empty stomach because they then don’t have to compete with the other proteins in the meal for absorption at the transporter sites in the small intestines. Empty stomach generally means two hours after a meal or half hour before a meal. It won’t harm to take glycine with meal, probably just less effective.
Glycine can act like a neurotransmitter and it can be synthesized in the body as well as degraded by the body.
Among the body’s amino acids, it is the simplest and the most abundant (especially in muscle and skin). It is not classified as an essential amino acid, which means that you do not have to take in from food or supplement because the body can synthesize it. However, in some cases the synthesis may be sub-optimal.
In previous post, it mentions that theanine can increase glycine in various areas of the brain.
How does glycine help you sleep?
As mentioned in Naturopathic Currents …
“Glycine undergoes passive diffusion through the blood-brain barrier and acts primarily on N-methyl-D-aspartate receptors (NMDA). Its actions on the NMDA receptor are believed responsible for inhibiting muscle activity during rapid eye movement (REM) sleep, and for lowering core body temperature to facilitate sleep. Oral glycine administration also increases serotonin levels without increasing dopamine levels to help normalize circadian rhythms.”
It can reduce the “spinning thoughts” in the head and relieve some of the symptoms of sleep deprivation. It can also help normalize sleep architecture.
There are also some study looking into “supplementing oral glycine as part of pharmacologic management of schizophrenia”.
Safety of Glycine
The supplement appears to be relatively safe where the article says “The safety of glycine supplementation has been clearly established.”
WebMD says …
“People being treated with clozapine should avoid taking glycine. Also people who have had a stroke should not take glycine without the supervision of a doctor.”
There is a genetic condition called glycine encephalopathy where some people are not able to degrade glycine and too much glycine accumulates in the blood. Obviously, people with this condition should not take additional glycine.
What foods contain glycine?
As is a good idea, if you want to get glycine from food instead of supplements. The foods high in protein like meat, fish, dairy products, and legumes contain glycine; although probably not as much as you can get in supplement form.
Glycine and BPH
Interestingly, it appears that EFA and zinc along with glycine and other amino acids may help with BPH symptoms…
“It’s likely that essential fatty acid (EFA) and zinc deficiencies are associated with BPH, particularly since EFAs are the nutritional precursors to prostaglandins that, in turn, inhibit testosterone from binding to the prostate (Prostate, 1983, 4(3): 247-51). Many studies have shown that a moderate zinc supplementation can prevent or improve BPH. Other evidence shows that taking certain amino acids – L-glutamic acid, L-alanine, glycine and L-glutamic acid – can also help the condition” [source]