Glycine

Glycine is a nonessential amino acid derived from the alkaline hydrolysis of gelatin. Glycine is the simplest of the 20 natural amino acids. Glycine is the only amino acid that does not have optical isomers. Glycine is a protein amino acid found in the protein of all life forms. It is the simplest amino acid in the body and the only protein amino acid that does not have chirality. Glycine is not considered an essential amino acid because the cells in the body can synthesize sufficient amounts of glycine to meet physiological requirements.

The body uses it to help the liver in detoxification of compounds and for helping the synthesis of bile acids. It has a sweet taste and is used for that purpose. Glycine is very evolutionarily stable at certain positions of some proteins, because mutations that change it to an amino acid with a larger side chain could break the protein's structure. Glycine is also similar to gamma-aminobutyric acid and glutamic acid in the ability to inhibit neurotransmitter signals in the central nervous system.

Glycine functions, uses, and health benefits

Glycine is essential for the synthesis of nucleic acids, bile acids, proteins, peptides, purines, adenosine triphosphate (ATP), porphyrins, hemoglobin, glutathione, creatine, bile salts, one-carbon fragments, glucose, glycogen, and l-serine and other amino acids. Glucagon is a hormone that causes glycogen (stored in the liver) to convert to glucose which is needed by the body for energy. Glycine increases the release of glucose into the blood stream by stimulating the glucagon hormone. Glycine is an inhibitory neurotransmitter in the central nervous system, especially in the spinal cord. Glycine systems may be important in controlling epilepsy and other CNS disorders.

Glycine also enhances the activity of neurotransmitters (chemical messengers) in the brain that are involved in memory and cognition. Glycine may be indicated to help alleviate the symptoms of spasticity. Glycine is an inhibitory amino acid with important functions centrally and peripherally. Molecular analogs and precursors can be used to augment these systems. The charged species have difficulty passing the blood-brain barrier and must be carried by transport pumps. Glycine helps convert many potentially harmful substances including toxic phenolic materials such as benzoic acid (sodium benzoate) into harmless forms.

Dietary sources of glycine

Glycine can be manufactured from other amino acids in the liver, it does not have to be obtained directly through the diet. Glycine is found in many foods high in protein, such as meat, fish, dairy products, and legumes. Glycine supplements can also be available on the market.

Glycine dosage, intake

Most people do not need to take glycine because the body can manufacture itself. Follow doctor’s advice for the supplemental use of glycine for the support of serious health conditions. Doses used for management of schizophrenia have ranged from 40 to 90 grams daily. Studies examining the role of glycine in the treatment of benign prostatic hyperplasia used doses ranging from 390 milligrams to 780 milligrams per day. Supplemental use of glycine at levels of 1 to 3 grams per day is useful in the treatment of certain forms of bipolar depression (manic depression).

Glycine deficiency

Usually the deficiency of glycine is rare because the body makes its own supply of the nonessential amino acids. A glycine deficiency may inhibit DNA synthesis.