This white paper was prepared for Natural Calm by Dr. Alison Smith to evaluate the benefits of magnesium glycinate and glycine as an amino acid. There are many marketing claims around glycine, however, we wanted to know the facts about how glycine works in the body.
Learn more about the amino acid, glycine, and how it works in magnesium glycinate.
Magnesium Glycinate and the Amino Acid, Glycine: Absorbability and Bioavailability
By Alison Smith Ph.D., Neuroscience
Which magnesium salt is most effective, in terms of absorbability and bioavailability?
Organic magnesium salts are created in a laboratory by combining an inorganic magnesium salt, derived from earth or rock sources, with either an acid or an amino acid.
Magnesium salts combined with amino acids are referred to as amino acid chelates.
Magnesium glycinate (also known as magnesium bisglycinate or magnesium diglycinate) is one such organic magnesium salt, or amino acid chelate, that is created by combining inorganic magnesium with an amino acid called glycine.
This white paper contains two parts. Part one explores the importance of glycine for human health, and part two investigates the absorbability and bioavailability of magnesium glycinate supplements.
Part I: What is Glycine?
Amino acids are the basic building blocks of proteins, and they are essential not only for a healthy body but for life itself. We simply could not exist without them––they ensure our survival and play an integral role in all cellular processes.
Scientists have discovered over 500 different amino acids in nature; however, the human body only requires twenty of them for human cellular function 3. These twenty amino acids are referred to as the standard amino acids 4.
The human body can naturally produce half of the standard amino acids––the other half, called the essential amino acids, must be acquired through the diet.
Glycine is classified as a non-essential amino acid since the body naturally produces it; however, research shows that the amount of glycine produced by the body is not sufficient enough to keep up with metabolic demands 5; therefore, oral supplementation or eating foods rich in glycine might be warranted.
Glycine is the smallest amino acid, so small that it can squeeze through the tiniest spaces 4. It plays a major role in collagen and elastin formation 6, as well as bile acid function.
Interestingly, it also acts as a neurotransmitter in the central nervous system 7. A chronic glycine deficiency can result in impairment of growth, immune and nervous system function, and nutrient metabolism 8.
Glycine: Implications for Health and Nutrition
Of the total amino acid content in the human body, 11.5% of it is glycine.
This amino acid plays a pivotal role in nutrition and metabolism, and for that reason, we require approximately 2 grams of glycine produced by the body or acquired through the diet each day.
80% of the total glycine in the body is used for protein synthesis, and without it, cellular function would suffer 9.
The following is a list of health conditions in which glycine plays a critical role:
Obesity and Type II Diabetes:
There is evidence that plasma concentration of glycine is reduced in obese and type II diabetic patients 10.
Oral glycine supplementation may be an effective treatment since it can reduce free fatty acids and triglycerides in the blood and fat cell size within intra-abdominal fat of obese subjects 11.
Glycine is anti-inflammatory and immunomodulatory 12. It reduces inflammatory reactions by encouraging an influx of chloride into the cell membrane thus hyperpolarizing the cell, decreasing calcium entry, thus making the cell less active overall.
Glycine also reduces the production of proinflammatory cytokines and the expression of adhesion molecules in blood vessels 13, and enhances the activity of macrophages and leukocytes––immune cells that help to clean up injured or infected tissue 14.
All of these effects have the potential to reduce atherosclerosis in cardiac patients 15.
Two separate double-blind studies showed that the administration of 3 grams of glycine, before bedtime, improved quality of sleep, the feeling of fatigue the next day, sleep satisfaction, and time to sleep onset 16,17.
No adverse side effects were observed even when subjects ingested up to 9 to 31 grams of glycine per day 18,19.
Nervous System Function:
Glycine and GABA (gamma-Aminobutyric acid) are the main inhibitory neurotransmitters of the central nervous system. They both activate receptors in the brain and spinal cord that allow an influx of chloride into central nervous system cells––chloride inhibits the cell thus reducing cellular activation 20.
Inhibition is an imperative process in the central nervous system; without it, normal behavioural and motor function would be impossible because inhibition allows precise movements, thoughts, and attention, and the ability to stop or change a neurological response.
Defects in inhibition result in psychiatric disorders like ADHD, obsessive-compulsive disorder (OCD), and Tourette’s syndrome 21. There is evidence that glycine supplementation may reduce OCD 22.
Glycine has also been shown to improve auditory nerve function in diabetic patients by reducing nerve damage imposed by excessive sugar in the bloodstream 23.
Through aerobic metabolism or some pathological processes, the body naturally produces oxidants: harmful substances like free radicals, hydrogen peroxide, and hydroxyl radicals that damage healthy tissues, protein, and DNA––a destructive process referred to as oxidative stress 24.
A cell’s ability to defend itself against oxidative stress depends on several antioxidant defence mechanisms including the production of glutathione: a tripeptide synthesized from the amino acids glycine, glutamate, and cysteine; it counteracts the activity of oxidants and reduces oxidative stress 25,26.
Two studies by Sekhar et al. 25,27 report that both diabetic and elderly patients have glutathione deficiency and supplementation with glycine and cysteine restores glutathione levels, which in turn reduces oxidative stress, diabetic symptoms, and aging.
Glycine supplementation also reduces oxidative stress and blood pressure in patients with metabolic syndrome and might benefit patients with vascular disease or atherosclerosis 15,28.
Following an ischemic stroke, it is incredibly important to receive treatment as soon as possible––the administration of medication to break down the blood clot in the brain before 4.5 hours post-stroke is ideal 29.
There is also preliminary evidence that 1-2 grams of sublingual glycine started within 6-hours post-stroke, and given for 5-days, has neuroprotective effects in ischemic stroke patients: it reduces mortality, the time period of neurological deficits, and the imbalance between excitatory and inhibitory neurotransmitters within the brain 30.
Research shows that supplemental glycine helps to protect muscle from certain wasting conditions such as cancer cachexia––muscle and fat wasting due to cancer 31,32, sepsis, or reduced caloric intake 33.
Glycine supplementation has anticancer properties. Evidence shows glycine to inhibit hepatic (liver) and B16 melanoma (skin) cancer cell proliferation and angiogenesis.
In the liver, a type of macrophage called Kupffer cells protect the liver against pathogens and toxins; however, in doing so, they produce oxidants––harmful substances that damage liver cells and cause cancer. Glycine supplementation is reported to block oxidant production by Kupffer cells, which in turn reduces liver cancer cell production 9.
Glycine also blocks blood vessel formation (angiogenesis) in B16 skin cancer (melanoma) tumours, reducing their size by upwards of 65% 9,34.
Connective Tissue Integrity:
Glycine is a precursor of collagen production: collagen is an important connective tissue component of skin, tendon, and cartilage; it provides function and structure to the body.
Being the smallest amino acid, glycine fits between the tight junctions between larger amino acids that help to form collagen proteins. Glycine is also a flexible amino acid, and it gives collagen its pliability and elasticity 9.
Glycine plays a protective role against alcohol-induced liver toxicity by shielding liver cell membrane structure from the damaging effects of oxidative stress produced by alcohol in the liver 35.
By slowing stomach emptying of alcohol and reducing the by-products of alcohol like acetaldehyde (a type of oxidant), glycine can reduce blood alcohol level and the damaging effects of alcohol 9.
Part II: The Effectiveness of Magnesium Glycinate Supplements
With the vast array of magnesium salts available in capsule, liquid, or powder form, consumers can be left feeling confused by all the choices. Which magnesium supplement should they choose? Which is the most effective?
Magnesium glycinate is a popular organic magnesium salt available as a supplement; however, there is very little research on its effectiveness in the human body in terms of absorbability and bioavailability.
Here is what the current research can tell us:
Magnesium Glycinate: Absorption and Bioavailability
Organic magnesium salts, like magnesium glycinate, are created in a laboratory by combining an inorganic magnesium salt with either an acid or an amino acid (a protein).
For example, magnesium citrate is created by combining an inorganic magnesium with citric acid, and magnesium glycinate is created by combining an
inorganic magnesium with the amino acid, glycine.
Magnesium glycinate is a type of organic magnesium salt; therefore, it is considered as a highly absorbable and bioavailable form of magnesium 1,2.
In a review article by Coudray et al. 2, magnesium glycinate is listed as a ‘good’ source of magnesium since it is soluble, absorbable, and bioavailable. Schuette et al. 36 report magnesium diglycinate as an absorbable form of magnesium for some patients with intestinal resection.
Magnesium Glycinate in the Treatment of Health Conditions
More research is required to understand how magnesium glycinate helps in the treatment of various health conditions.
The current research demonstrates that 300 mg of magnesium bisglycinate, given daily, significantly reduces the frequency and intensity of pregnancy-induced leg cramps 37.
The administration of 125-300 mg of magnesium glycinate or taurinate is reported to help in rapid recovery from major depression 38.
Intestinal Absorption of Amino Acid Chelates
How the intestine absorbs magnesium glycinate is not entirely understood. The predominant absorption mechanism described in the literature involves a magnesium salt breaking apart in the gastric juices of the stomach; this process releases ionic magnesium, ready for absorption through the intestine.
The ionic magnesium then travels to the distal intestine where it is absorbed through passive diffusion or via facilitated diffusion through ion channels 39,40.
There is a theory that amino acid chelates, including magnesium glycinate, are absorbed by a different mechanism; however, it has not been confirmed.
The theory states that amino acid chelates remain intact despite exposure to gastric juices in the stomach. The complex, instead, enters the intestine whole and is absorbed by peptide channels in the intestinal wall, opposed to passive diffusion or facilitated diffusion through ion channels 41.
Again, this theory has not been proven and more research is required.
For more information on the science behind magnesium absorption and how magnesium citrate compares to magnesium glycinate, see the results of a 2017 clinical trial currently under peer review for publication.
- Ranade VV, Somberg JC. Bioavailability and pharmacokinetics of magnesium after administration of magnesium salts to humans. American Journal of Therapeutics. 2001;8(5):345.
- Coudray C, Rambeau M, Feillet-Coudray C, et al. Study of magnesium bioavailability from ten organic and inorganic mg salts in mg-depleted rats using a stable isotope approach. Magnesium research. 2005;18(4):215.
- Cole L, Kramer P. Human physiology, biochemistry and basic medicine. Cambridge, Massachusetts: Academic Press; 2016.
- New World Encyclopedia. Amino acid. https://www.newworldencyclopedia.org/p/index.php?title=Amino_acid&oldid=684821. Accessed January, 2018.
- Meléndez-Hevia E, de Paz-Lugo P, Cornish-Bowden A, Cárdenas M. A weak link in metabolism: The metabolic capacity for glycine biosynthesis does not satisfy the need for collagen synthesis. J Biosci. 2009;34(6):853-872.
- Wu G. Amino acids: Metabolism, functions, and nutrition. Amino Acids. 2009;37(1):1-17.
- Rajendra S, Lynch JW, Schofield PR. The glycine receptor. Pharmacology and Therapeutics. 1997;73(2):121-146.
- B Matilla, J L Mauriz, J M Culebras, J González-Gallego, P González. Glycine: A cell-protecting anti-oxidant nutrient. Nutrición hospitalaria. 2002;17(1):2-9.
- Razak M, Begum P, Viswanath B, Rajagopal S. Multifarious beneficial effect of nonessential amino acid, glycine: A review. Oxidative Medicine and Cellular Longevity. 2017;2017.
- Felig P, Marliss E, Cahill GF. Plasma amino acid levels and insulin secretion in obesity. The New England Journal of Medicine. 1969;281(15):811-816.
- Perez I, Banos G, El Hafidi M, Zamora J, Soto V, Carvajal-Sandoval G. Glycine intake decreases plasma free fatty acids, adipose cell size, and blood pressure in sucrose-fed rats. The American Journal of Physiology. 2004;287(6):R1387.
- Wang W, Wu Z, Dai Z, Yang Y, Wang J, Wu G. Glycine metabolism in animals and humans: Implications for nutrition and health. Amino Acids. 2013;45(3):463-477.
- Hasegawa S, Ichiyama T, Sonaka I, et al. Cysteine, histidine and glycine exhibit anti‐inflammatory effects in human coronary arterial endothelial cells. Clinical & Experimental Immunology. 2012;167(2):269-274.
- Li P, Yin Y, Li D, Woo Kim S, Wu G. Amino acids and immune function. British Journal of Nutrition. 2007;98(2):237-252.
- Díaz-Flores M, Cruz M, Duran-Reyes G, et al. Oral supplementation with glycine reduces oxidative stress in patients with metabolic syndrome, improving their systolic blood pressure. Canadian Journal of Physiology and Pharmacology. 2013;91(10):855-860.
- Inagawa K, Hiraoka T, Kohda T, Yamadera W, Takahashi M. Subjective effects of glycine ingestion before bedtime on sleep quality.
Sleep Biol Rhythms. 2006;4(1):75-77.
- Yamadera W, Inagawa K, Chiba S, Bannai M, Takahashi M, Nakayama K. Glycine ingestion improves subjective sleep quality in human volunteers, correlating with polysomnographic changes. Sleep Biol Rhythms. 2007;5(2):126-131.
- Kentaro I, Nobuhiro K, Kaori O, Eiji S, Shoji T, Michio T. Assessment of acute adverse events of glycine ingestion at a high dose in human volunteers. Seikatsu Eisei (Journal of Urban Living and Health Association). 2006;50(1):27-32.
- Rose W, Wixom R, Lockhart H, Lambert G. The amino acid requirements of man. J Biol Chem. 1995;217:987-996.
- O’Brien J, Berger A. Cotransmission of GABA and glycine to brain stem motoneurons. Journal of Neurophysiology. 1999;82(3):1638-1641.
- Garavan H, Ross TJ, Stein EA. Right hemispheric dominance of inhibitory control: An event-related functional MRI study. Proceedings of the National Academy of Sciences of the United States of America. 1999;96(14):8301-8306.
- Cleveland W, DeLaPaz R, Fawwaz R, Challop R. High-dose glycine treatment of refractory obsessive-compulsive disorder and body dysmorphic disorder in a 5-year period. Neural Plasticity. 2009;2009:1-25.
- Muñoz-Carlin MdL, Rodríguez-Moctezuma JR, Gómez Latorre JG, Montes-Castillo ML, Juárez-Adauta S. Effects of glycine on auditory evoked potentials among diabetic patients with auditory pathway neuropathy. Revista médica de Chile. 2010;138(10):1246.
- Sies H. Oxidative stress: Oxidants and antioxidants. Experimental Physiology. 1997;82:291-295.
- Sekhar RV, McKay SV, Patel SG, et al. Glutathione synthesis is diminished in patients with uncontrolled diabetes and restored by dietary supplementation with cysteine and glycine. Diabetes care. 2011;34(1):162-167.
- Cruz M, Maldonado-Bernal C, Mondragón-Gonzalez R, et al. Glycine treatment decreases proinflammatory cytokines and increases interferon-γ in patients with type 2 diabetes. J Endocrinol Invest. 2008;31(8):694-699.
- Sekhar RV, Patel SG, Guthikonda AP, et al. Deficient synthesis of glutathione underlies oxidative stress in aging and can be corrected by dietary cysteine and glycine supplementation. The American journal of clinical nutrition. 2011;94(3):847-853.
- El Hafidi M, Pérez I, Baños G. Is glycine effective against elevated blood pressure? Current opinion in clinical nutrition and metabolic care. 2006;9(1):26-31.
- Schellinger PD, Köhrmann M. 4.5-hour time window for intravenous thrombolysis with recombinant tissue-type plasminogen activator is established firmly. Stroke; a journal of cerebral circulation. 2014;45(3):912-913.
- Gusev EI, Skvortsova VI, Dambinova SA, et al. Neuroprotective effects of glycine for therapy of acute ischaemic stroke. Cerebrovascular Diseases. 2000;10(1):49-60.
- Bennani-Baiti N, Walsh D. What is cancer anorexia-cachexia syndrome? A historical perspective. The journal of the Royal College of Physicians of Edinburgh. 2009;39(3):257.
- Ham DJ, Murphy KT, Chee A, Lynch GS, Koopman R. Glycine administration attenuates skeletal muscle wasting in a mouse model of cancer cachexia. Clinical nutrition (Edinburgh, Scotland). 2014;33(3):448-458.
- Koopman R, Caldow M, Ham D, Lynch G. Glycine metabolism in skeletal muscle: Implications for metabolic homeostasis. Current Opinion in Clinical Nutrition & Metabolic Care. 2007;20(4):237-242.
- Rose M, Madren J, Bunzendahl H, Thurman G. Dietary glycine inhibits the growth of B16 melanoma tumors in mice. Carcinogenesis. 1999;20(5):793-798.
- Yin M, Ikejima K, Arteel G, et al. Glycine accelerates recovery from alcohol-induced liver injury. Journal of Pharmacology and Experimental Therapeutics. 1998;286(2):1014-1019.
- Schuette SA, Lashner BA, Janghorbani M. Bioavailability of magnesium diglycinate vs magnesium oxide in patients with ileal resection. Journal of Parenteral and Enteral Nutrition. 1994;18(5):430-435.
- Supakatisant C, Phupong V. Oral magnesium for relief in pregnancy-induced leg cramps: A randomised controlled trial. Maternal & Child Nutrition. 2015;11(2):139-145.
- Eby KL, Eby GA. Rapid recovery from major depression using magnesium treatment. Medical Hypotheses. 2006;67(2):362-370.
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- Olivares M, Pizarro F, Pineda O, Name JJ, Hertrampf E, Walter T. Milk inhibits and ascorbic acid favors ferrous bis-glycine chelate bioavailability in humans. The Journal of nutrition. 1997;127(7):1407.
Magnesium Glycinate FAQs
Have you been wondering about the benefits of taking magnesium glycinate? Magnesium glycinate can offer numerous benefits, and it is readily bioavailable, making it useful for multiple applications and uses. Commonly, magnesium glycinate is used to help with muscle pain, aches, and the like; however, some people also use magnesium glycinate to help with reducing stress, anxiety, and improving general health.
If you have been looking for a magnesium supplement, then it’s natural to wonder what glycinate is and how this impacts on the magnesium content of your supplements. Fortunately, magnesium glycinate is just another form of magnesium, alone with other forms such as magnesium citrate and magnesium oxide. Magnesium glycinate supplements are beneficial for numerous applications, but most notably for muscle pains.
If you’ve been looking to improve your quality of sleep, then magnesium supplements could be a good option to consider. In fact, as many as 65% of Canadians find themselves suffering from a magnesium deficiency – showing how widespread this nutritional imbalance is! If you want to try magnesium glycinate supplements for sleep, a suitable dosage for adults is usually around 300mg.
Magnesium glycinate provides a readily available source of magnesium, making it a popular supplement form. Magnesium glycinate for anxiety is created by combining inorganic magnesium with the premium-quality organic amino acid glycine. In turn, this provides a bioavailable source of magnesium that can have numerous beneficial effects on your health, including for anxiety reduction. Hence, magnesium glycinate is evidently a beneficial supplement to consider if you’ve been struggling with stress or anxiety.