While researching enteritis (inflammation of the small intestine) I came across some very interesting research on an amino acid called glycine. Turns out this very simple, and abundant, amino acid is very important for gut health. Strangely enough, we aren’t getting enough of it. Supplementing glycine may be one of the most important things you can do to heal your gut and combat systemic inflammation.
Glycine is one of the major health components of bone broth soup, as it is abundant in cartilage, collagen, bones, tendons, etc. Those parts of the animal we usually throw away. It is also found in gelatin sources (even Jello). Glycine is found in high amounts in the human body as it is one of the main components of the most abundant protein in the body, collagen. Collagen is found mostly in fibrous tissue such as tendons, ligaments, skin, cartilage, blood vessels, and the gut (see studies below). Glycine is considered a “non-essential” amino acid, which simply means that it is so important the liver can actually make it should it become necessary.
So if Glycine is so abundant in the body, and the liver can make it, why do we need to worry about supplementing it? The liver can only produce a limited amount of glycine. The liver also uses glycine for detoxification and this process is limited by the amount of glycine available (Westonaprice.org). What is made by the liver is used for essential functions, those functions that help keep us alive long enough to go kill some food to replenish our glycine. For most “routine” functions in the body the glycine needs to be circulating in the blood stream.
Inflammation is the body’s first response to injury and infection. However the inflammation should normally clear up very quickly after an injury, but only if glycine is found in high amounts. If you have aches and pains long after a simple injury, or you have unexplained aches and pains quite often, you may very well be deficient in glycine. When you’re glycine deficient you can suffer inflammation from any tissue injury, even micro injuries such as what occurs all the of the time in arteries. Glycine is known to be protective of such injuries and may help prevent heart disease. One of the most important roles of glycine is to regulate inflammation in the body; when this isn’t functioning correctly we develop chronic inflammation.
Why is it when we have an injury that the doctor tells us to put ice on it? It is to reduce inflammation. But why? Because inflammation caused by injury actually slows healing, can cause additional injury, and it causes us pain. So why is it that the body is making an injury worse, rather than better? Dysfunction, the body is reacting in a way that is counterproductive to healing. When the body is not fed correctly, be it a lack of minerals or proper amino acids, such as glycine, it can become dysfunctional and doesn’t react the way it should. Often this is due to normal feed-backs (signally) not working correctly; in other words, the body isn’t being told that it no longer needs to cause inflammation. One reason is glycine. Glycine is required for a proper inflammation response and our modern diets are deficient in glycine.
“You probably throw away 8-10 grams of glycine per day” — Dr. Joel Brind, PhD
Our foods, especially meat should be high in glycine, and the animals we eat are. The bones, cartilage, bones, tendons, skin, etc. are all very high in glycine. The problem is we don’t eat those parts any more. I can’t tell you how many people I know that the only meat they eat is boneless, skinless, chicken breasts. Probably one of the least nutritious animal protein sources on the planet, especially modern chicken, what little fat the chicken breast contains is very high in Omega 6. Omega 6 further aggravates the Omega 6:Omega 3 imbalance that most modern diets provide and causes even more inflammation. We’re literally throwing away some of the most nutritious parts of the animals we eat (e.g., chicken feet are very high in collagen and glycine). Our ancestors would never have done this, we evolved eating much more of the animal, usually using all of it, wasting none of the animal. Our liver also needs much more glycine today than it did in the past as it uses glycine to detoxify methionine, an amino acid found in lean meat. It is estimated that we consume 10 times more methionine that we did traditionally.
Normal inflammation is part of the body’s immune response to injury and disease. When we’re injured our first response to inflammation is to try to get rid of it, ice it down, take anti-inflammatory drugs, etc. If the body is functioning normally this is a bad idea as inflammation is a natural part of healing and if glycine levels are normal the inflammation will generally not last very long. When we have infections caused by microbes inflammation is used to fight the infection. Glycine is the most important inflammatory regulator in the body, without enough of it inflammation can continue, basically unchecked, much longer than necessary to fight infection. Chronic excess inflammation is the most common cause of unexplained aches and pains. This is often due to low glycine levels.
It is my recommendation that anyone with gut issues should be taking about 10 grams of glycine per day (research studies have safely used up to 100 grams per day). This is how much glycine is estimated that we throw away from food, what we would have consumed in previous generations. This is how much I consume and I started seeing results very quickly. Not only on a little lingering gut pain that I’ve had, but also on joint pain, mood and sleep. Taking glycine is especially important if you are not consuming bone broths. Glycine has a slightly sweet taste and dissolves well, so it is easy to add to smoothies or the Gut Healing Golden Kefir. Or just mix it in water. (I am personally taking the l-glycine powder located here, as always, buy where you find it the cheapest)
“The primary physical effect of the inflammatory response is for blood circulation to increase around the infected area. In particular, the blood vessels around the site of inflammation dilate, permitting increased blood flow to the area. Gaps appear in the cell walls surrounding the infected area, allowing the larger cells of the blood, i.e. the immune cells, to pass. As a result of the increased blood flow, the immune presence is strengthened. All of the different types of cells that constitute the immune system congregate at the site of inflammation, along with a large supply of proteins, which fuel the immune response. There is an increase in body heat, which can itself have an anti-biotic effect, swinging the balance of chemical reactions in favour of the host… Ideally, the inflammatory response should only last for as long as the infection exists. Once the threat of infection has passed, the area should return to normal existence.” — crohn.ie
“Glycine protects against shock caused by hemorrhage, endotoxin and sepsis, prevents ischemia/reperfusion and cold storage/reperfusion injury to a variety of tissues and organs including liver, kidney, heart, intestine and skeletal muscle, and diminishes liver and renal injury caused by hepatic and renal toxicants and drugs…Glycine appears to exert several protective effects, including antiinflammatory, immunomodulatory and direct cytoprotective actions. Glycine acts on inflammatory cells such as macrophages to suppress activation of transcription factors and the formation of free radicals and inflammatory cytokines.” — PubMed #12589194
“Glycine protects mammalian intestine against oxidative damage caused by ischaemia-reperfusion (IR) injury and prevents or reverses experimentally-induced colitis. However the mechanism of protection remains largely unknown… Glycine is a well-documented cytoprotective agent…dietary glycine also prevented or reversed experimentally-induced colitis, suggesting a possible beneficial effect of glycine supplementation in inflammatory disease of the bowel ” — PubMed #PMC2849964
“dietary glycine is protective in the kidney against cyclosporin A toxicity and ischemia-reperfusion injury. Glycine may be useful clinically for the treatment of sepsis, adult respiratory distress syndrome, arthritis, and other diseases with an inflammatory component.” — PubMed #11212343
“Glycine is a well-documented cytoprotective agent and protects mammalian intestine against ischemia-reperfusion injury, irradiation and experimentally induced colitis.” — PubMed #21628872
“The epithelial glycine transporter GLYT1: protecting the gut from inflammation” “ample evidence has been generated demonstrating that glycine has efficacy as an anti-inflammatory and cytoprotective agent… While the mechanism(s) responsible for the protective effects of glycine are unclear, they are likely to be multi-factorial involving direct effects on target cells, inhibition of glycine-gated chloride channels and/or inhibition of inflammatory cell activation… In this issue of The Journal of Physiology, Howard et al. (2010) used human intestinal epithelial cell lines to investigate the role of GLYT1 in the cytoprotective effect of glycine against oxidative stress. Exogenous glycine protected Caco-2 and HCT-8 cell lines against the oxidative agent tert-butylhydroperoxide and reduced the intracellular concentration of reactive oxygen species… The authors concluded that the protective effect of glycine was mediated, at least in part, by preservation of intracellular glutathione content… glycine has been shown to protect against intestinal injury in well-established chemical models of colitis… direct effects of glycine on intestinal epithelial cells could exert a specific impact on the overall inflammatory status of the intestine” — PubMed #PMC2852991
“this nutritional concept might be a new option for the treatment of chronic inflammatory diseases.” — PubMed #17996689
The sodium nitrate in processed foods such as hotdogs, salami, bacon, ham and most cured meats can inhibit the intestines ability to absorb glycine. — PubMed #9541967
Glycine may also improve fructose malabsorption “There is some recent evidence that high-fructose diets in rats likewise impair the intestinal barrier function, leading to an activation of Kupffer cells that exacerbates fructose-induced steatosis.88–90 It is reasonable to suspect that a high-glycine diet would be protective in this regard” — Pubmed #PMC4195924
“Glycine affords protection from sucrose-induced metabolic syndrome…Of particular interest are studies showing that high glycine intakes can counteract many of the adverse effects of a high-sucrose diet on the liver, adipose mass and vascular function” — PubMed #PMC4195924
“These results suggest that dietary Gly (glycine) supplementation modulates the inflammatory response partly through changes in the expression of pro-inflammatory cytokines such as IL-1, IL-6, IFN-gamma and TL1A.” — PubMed #18377692
“Obese patients have an impaired inflammatory profile that contributes to the development of vascular complications, with fat tissue being partially responsible for controlling both processes: energy balance (through PPAR) and inflammatory condition (through inflammatory markers). White adipose tissue produces cytokines (IL-6, TNF-α, resistin, adiponectin, etc.) and participates in a broad spectrum of processes. Recently, glycine has been reported to have anti-inflammatory properties which reduce TNF-α and IL-6 levels and increase adiponectin in 3T3-L1 adipocytes and in fat tissue of obese mice.” — PubMed #19864106
“The present results demonstrate that glycine selectively protects the small intestine during subacute endotoxemia, even after manifestation of a severe systemic impairment. Because glycine is non-toxic at low doses, an administration of a moderate glycine dose (50-100 mg/kg) may be suitable to protect from intestinal damage during sepsis.” — PubMed #25012270
“glutamine is depleted from muscle stores during severe metabolic stress including sepsis and major surgery. Therefore it is considered conditionally essential under these conditions…Glutamine has an important role in cell-mediated immunity and the integrity of the intestinal mucosa…Glutamine supplementation during illness increases gut barrier and lymphocyte function… Three amino acids are needed to synthesize glutathione: glycine, glutamic acid and cysteine. Glutamine is easily converted to glutamic acid and produces an antioxidant glutathione.” Glutathione is one of the most important antioxidants in the body, often referred to as “The Mother of All Antioxidants”
“Adjunctive high-dose glycine in the treatment of schizophrenia – A significant 34% reduction in negative symptoms was observed during glycine treatment.” — PubMed #11806864
“Glycine-induced augmentation of NMDA receptor-mediated neurotransmission may thus offer a potentially safe and feasible approach for ameliorating persistent negative symptoms of schizophrenia.” — PubMed #9892253
ABNORMAL GLYCINE METABOLISM IN RHEUMATOID ARTHRITIS — PubMed #PMC436502
This work supports the hypothesis that glycine prevents reactive arthritis by blunting cytokine release from macrophages by increasing chloride influx via a glycine-gated chloride channel. — PubMed #11500467
“Glycine also protects against peptidoglycan polysaccharide-induced arthritis and inhibits gastric secretion and protects the gastric mucosa against chemically and stress-induced ulcers… Multiple protective effects make glycine a promising treatment strategy for inflammatory diseases.” — PubMed #12589194