Glycine: What is it? How can it help?

What is Glycine?

Glycine is an amino acid that plays several important roles in the body. Glycine is a non-essential amino acid, which means that the body can produce it on its own, or it can be obtained through diet. Glycine plays a crucial role in several physiological functions such as protein synthesis, neurotransmission, collagen, detoxification, sleep support, and gut health. 

What are the Benefits of Glycine?

Improves Sleep Quality

Glycine has been shown to help improve sleep by calming the nervous system. Glycine works to lower body temperature (Kawai et al., 2010), which can promote deeper and more restful sleep (Bannai et al., 2012; Inagawa et al., 2006). Yamadera et al. ( 2007) found that glycine improved sleep quality and sleep efficacy (sleep time/in-bed time), and shortened PSG latency both to sleep onset and to slow wave sleep. 

Supports Cognitive Function

Glycine acts as an inhibitory neurotransmitter in the central nervous system. Glycine has been shown to modulate nerve impulses, contributing to relaxation and reducing symptoms of anxiety and stress. Glycine has also been shown to enhance memory and cognitive function and has been shown to improve symptoms of schizophrenia and obsessive-compulsive disorder (OCD).

Greenberg et al. (2009) conducted a 12 week, randomized, double blind study to explore whether adding glycine (an amino acid that helps in glutamate receptor N-methyl-D-aspartate (NMDA) transmission) vs. placebo would help enhance medication treatments. This particular study included 24 participants who all had a previous diagnosis of Obsessive Compulsive Disorder. Each participant consumed 60 grams of glycine a day to their medication or consumed a placebo. The results of this study indicated that participants in the glycine group experienced statistically significant reduction in OCD symptoms compared to placebo. 

Improves Muscle Health

Glycine is essential for the synthesis of creatine, which helps supply energy to muscles. It may also help reduce muscle loss associated with aging (Liu et al., 2016).

Supports Collagen Production

As a major component of collagen, glycine supports skin, joint, and bone health. This makes it beneficial for maintaining youthful skin and preventing joint pain amd osteoarthritis (De Paz-Lugo et al., 2018).

Anti-inflammatory Properties

Glycine has anti-inflammatory and antioxidant effects and has been shown to help modulate the immune system and reduce the risk of chronic diseases and improve overall immune function (Aguayo-Cerón et al., 2023).

Improves Metabolic Health

Glycine plays a role in glucose metabolism and insulin sensitivity. Glycine supplementation has been shown to help manage blood sugar levels and reduce the risk of type 2 diabetes, obesity, hyperlipidemia and hypertension (Imenshahidi & Hossenzadeh, 2022).

Supports Gut Health

Glycine is important for maintaining the integrity of the gut lining and can help prevent leaky gut syndrome, which is linked to various autoimmune and inflammatory conditions (Liu et al., 2016).

Food Sources of Glycine

Meat

Chicken: Especially the skin and connective tissues.

Beef: High levels in cuts with more connective tissue, such as shanks, oxtail, and brisket.

Pork: Pork skin and cuts with higher collagen content.

Fish

Salmon: High in glycine, especially in the skin.

Cod: A good source, particularly in parts like the skin and bones.

Gelatin

Bone Broth: Made from simmering bones and connective tissue, bone broth is extremely rich in glycine.

Gelatin Powder: Used in cooking or as a supplement, it’s derived from animal collagen and is a concentrated source of glycine.

Dairy Products

Milk: Contains glycine, though in lower amounts compared to meat.

Legumes:

Lentils: Another plant-based source.

Black Beans: Provide a good amount of glycine.

Eggs

Eggs, especially the whites, contain glycine, although in smaller amounts compared to meat and fish.

Seeds and Nuts:

Sesame Seeds: Rich in various amino acids, including glycine.

Pumpkin Seeds: Also provide glycine.

Fruits and Vegetables:

While fruits and vegetables contain less glycine compared to animal products, they still contribute to your overall intake.

We recommend combining foods rich in glycine with other high-protein foods for optimal absorption and utilization by the body.

Who should avoid Glycine?

Glycine has also been shown to have no adverse reactions or side effects (Inagawa et al., 2006). 

If you are pregnant, nursing or are taking medications, please speak to your prescribing physician prior to starting any new medication or supplement. 

Our Favorite Glycine Supplements?

As with any supplements, we want to ensure that we are consuming the highest quality ingredients without any additives. See Dr. Miller’s favorite glycine supplements here.

Here at Well Mind Body we understand that a nutrient dense diet is vital for optimal health and wellness. We encourage our clients to get nutrients come from food and also understand that in some cases, supplementation can be very helpful. We also offer Nutrigenomic testing for our clients to help them better understand which foods best align with their genetics.