Glycine – A Hidden Gem For Sleep

By Dr Ernst
February 11, 2019

Glycine is an amino acid that is primarily found in red meats, fish, dairy and legumes. Even though its classified as “non-essential” (i.e. your body can make it when needed) the majority of American’s are missing this powerful amino acid.

Glycine is known to have a calming effect on your brain. It is a known inhibitor of neurotransmitters which can helping in “winding down” or “turning off” your brain before sleeping.

Glycine also acts as an essential building block to many other essential proteins in your body including collagen, hemoglobin, DNA/RNA, glutathione and is heavily involved in methylation detoxification reactions.

Sleep – Glycine Connection

Have you ever hit the bed only to find it nearly impossible to fall asleep? According to the National Institute of Neurological Disorders & Stroke – approximately 40 million Americans (~10% of the population) suffer from chronic long-term sleep disorders, most commonly difficulty falling asleep. Laying there restless, counting anything you can think of and constantly checking the clock can even create an anxiety like situation which only makes sleeping more difficult.

Sleep issues can spill over into various health problem – research now says lack of sleep can affect everything from mental capacity to in- creased risks for cancer, heart disease, diabetes and even obesity!

Glycine can promote sleep safely – unlike OTC and prescriptive sleep aids. A recent study showed that adults who consumed 3,000 mg (3 grams) of glycine had improved sleep ability compared to those who took a placebo. The improvements were noted in both amount of time it took to fall asleep and the ability to email asleep in a deep sleep state – promoting normal nocturnal sleep cycles.

Glycine Affects Core Body Temperature

So, what is it about this tiny amino acid that could be so powerful in contributing to regulating such a complex process as sleep? First of all, glycine taken orally has easy access to the brain – it readily crosses the blood brain barrier via glycine transporters. Once in the brain, glycine targets glutamate NMDA receptors in the suprachiasmatic nucleus (SCN) – the 24-hour biological clock in the central nervous system that controls when we want to be asleep and awake. By modulating NMDA receptors in the SCN, glycine induces vasodilation throughout the body to promote lowering of core body temperature.

Sleep and body temperature are well connected – in normal circadian sleep cycle, body temperature decreases just before the onset of sleep and continues to decrease throughout the night, reaching its lowest point approximately 2 hours after sleep onset, only to gradually rising again once you wake. Temperature is just one of many 24-hour rhythms your body experiences and the drop at night is important for initiating sleep. (This is why you have probably heard one technique for sleeping well is to lower the temperature of your bedroom at night – ideally 60-67 degrees Fahrenheit).

Did you know that OTC and prescription sleep aids work by forcing your body to enter a lower core temperature – thus inducing sleep? Glycine’s can produce the exact same effect on temperature regulation but without the negative side effects of medications (grogginess, fatigue and overall sleepiness during the next day).

Glycine Improves Waking Energy & Performance

Here’s where this gets really exciting – unlike many sleep aids out there, nutraceutical or pharmaceutical, glycine actually offsets feelings of fatigue and sleepiness during the day. Study participants who used glycine to help fall asleep showed improved reaction times in in the psychomotor vigilance test compared to the placebo group and reported feeling refreshed.

Glycine was found to contribute to yet another circadian process – stimulating the expression of arginine vasopressin – a neuropeptide produced in the SCN. Animal studies show that the expression levels of arginine vasopressin were increased during the day in the glycine treatment group

Arginine vasopressin serves as an output signal of the hypothalamic biological clock, an important regulator of circadian processes involving the hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary- gonadal (HPG) axes and the autonomic nervous system. Specifically, to the HPA axis, arginine vasopressin enhances output of corticotropin releasing hormone (CRH) which facilitates the release of adrenocorticotropic hormone (ACTH) which ultimately triggers the production of cortisol from the adrenal glands, thus contributing to the state of wakefulness.

Sleep isn’t just for “sleeping” – its perhaps one of the most important times your body cleans itself of toxins. Sleep has also been shown to activate neurological regeneration. Think about sleep as a form of neural detoxification – during sleep, waste products from your brains daily activities are removed from the tiny spaces between brain cells. Sleep, therefore, is like a “power wash” that restores and rejuvenates the brain for optimal function.

Considering glycine’s known prominent role in detoxifications processes of the liver, gallbladder, colon and blood it seems to reason that additional processes glycine helps regulate to support a healthy brain, which helps to promote not only healthy sleep – but a healthy body.

Suggested adjust daily glycine intake: 3-4 grams before sleeping. Children: 1-2 grams before sleeping.

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