Glycine

Figure 1. The chemical structure of (neutral) Glycine.

Glycine is an amino acid that has a single hydrogen atom as its side chain. It is also the simplest stable amino acid. Within the human body, Glycine is integral for the formation of protein structures and also an inhibitory neurotransmitter, whereby interference with its release in the spinal cord may cause spastic paralysis and uninhibited muscle contraction.

Food Sources

Glycine is not essential to the human diet, as Glycine can be biosynthesized in the body from the amino acid serine. Nevertheless, some good food sources of Glycine include protein-rich foods such as:

• Sesame seeds
• Pumpkin seeds
• Squash seeds
• Beef
• Turkey
• Chicken
• Pork
• Peanuts
• Crustaceans
• Salami
• Salmon
• Almonds
• Mackerel
• Leeks
• Parmesan cheese
• Soybeans
• Bread
• Eggs
• Lentils

Taken as a Dietary Supplement

Glycine is one of three amino acids that the human body uses to make glutathione, a powerful antioxidant. Glycine is also one of three amino acids that the human body uses to make creatine. Creatine provides muscles with energy to perform quick, short bursts of activity (e.g. sprinting, weightlifting).

Glycine is the primary amino acid found in Collagen, which is the most abundant protein in the human body. In fact, every third or fourth amino acid in Collagen is a Glycine.

As both glutathione and collagen tend to decrease naturally with age, a dietary intake of Glycine may help promote the production of these compounds within the human body.

Glycine is also taken to improve sleep quality, protect the liver from alcohol damage, protect the heart, increase insulin response in type 2 diabetes, and protect against muscle loss. However, there is insufficient scientific evidence presently to conclusively ascertain the benefits of Glycine in these applications.