An exciting new study, recently published in the Journal of Functional Foods, has discovered that by increasing the consumption of a tiny amino acid in our diet we can significantly reduce the severity, frequency, and duration of viral infections like common colds and flu.

Previous studies have shown that we are all seriously deficient in this simplest of amino acids, Glycine, which is essential in ensuring we maximize our collagen turnover and uphold the integrity of our extracellular matrix (ECM).

The ECM, mainly composed of collagen, is a mechanical barrier against infective agents, including viruses.

Glycine is a very effective mechanical defense, which by promoting the restoration and renewal of collagen in the ECM, can prevent or block the invasion of infectious agents.

The study, performed by Professor Enrique Meléndez-Hevia et al 2021, of the Institute of Cellular Metabolism in Spain, confirms that a weak bodily collagen structure renders us more susceptible to the entry of viruses and other infectious agents and it’s all because of our universal deficiency of the amino acid Glycine.

Highlights of the study include:

• The extracellular matrix is a physical barrier against infectious agents.
• Collagen (high glycine content) is the main protein of the extracellular matrix.
• Glycine is an essential amino acid as studies have previously demonstrated.
• Glycine deficiency causes a weak mechanical system including the extracellular matrix.
• Glycine intake as nutritional supplement was very effective against virus infections.

Invasive agents (bacteria, fungi, protozoa, or viruses) advance in the body to invade new areas through our ECM, which not only is the mechanical support of our tissues throughout our entire body, but importantly, also acts as a mechanical barrier that impedes or blocks the invasion of infective agents and prevents their expansion within the body.

In fact, many invasive agents secrete enzymes to destroy the collagen of the ECM to allow or improve their advance and proliferation through the tissues.

The ECM must be continuously regenerated and remodeled in order to eliminate old damaged collagen, which accumulates deteriorations in its structure, and to resynthesize new molecules.

You see, the ECM is made up of collagen and elastin, of which collagen constitutes approximately 25–33% of the total protein in our bodies. Glycine makes up one third of collagen, which means you need a high availability of this amino acid to support a healthy turnover of collagen.

Furthermore, the worsening of our mechanical system due to the deterioration of collagen will affect not only cartilage, bone, tendons, ligaments, etc., but the entire connective system of the ECM that is found in all tissues.

Besides replenishing collagen and improving immunity, our body uses glycine to: (1) prevent tissue injury; (2) enhance anti-oxidative capacity; (3) promote protein synthesis and wound healing; and (4) treat metabolic disorders in obesity, diabetes, cardiovascular disease, ischemia-reperfusion injuries, cancers, and various inflammatory diseases.

Imagine your body as a well-fortified castle. The strong outer walls are your first line of defense, keeping invaders at bay. In this analogy, the castle walls are your ECM, a complex web of proteins that surrounds and supports your cells. Now, viruses are like sneaky siege weapons, trying to breach the walls and take over your castle (your cells).

The Battle Plan: Building Stronger Walls

Professor Enrique Meléndez-Hevia and his team of researchers focused on the ECM, specifically collagen, the main protein that gives your walls (and your skin!) its structure. Healthy collagen turnover is essential for maintaining a strong ECM barrier. Here's where glycine comes in: it's a building block for collagen synthesis. The study hypothesized that increasing glycine availability could reinforce the ECM, making it harder for viruses to penetrate.

Viruses are cunning. They constantly evolve to find weaknesses in our defenses. If the ECM weakens, viruses can exploit these gaps, gaining access to healthy cells and causing infections. This is especially concerning for people with frequent viral infections, where a compromised ECM might be a contributing factor.

The Experiment: Putting the Walls to the Test

The Meléndez-Hevia study suggests that insufficient glycine levels might lead to a weakened ECM, making you more susceptible to viral infections.

The study investigated the potential of glycine supplementation to strengthen the ECM and fight viral invasiveness. Researchers divided volunteers with frequent viral infections into two groups. One group received a daily dose of glycine, while the other received a placebo.

It was conducted over a three-year period with 127 volunteers ranging between the ages of 15 and 70, who usually had the flu and/or the common cold every year (17 of them two or more times each year). They were divided into two groups (85 who took Glycine and 42 who did not).

The 85 were advised to take glycine as the only nutritional supplement, 10 g/day, divided into two doses of 5 g with breakfast and dinner. 

All of them were warned that they should maintain a diet rich in a range of amino acids (such as high-quality protein); otherwise, part of the Glycine would be used in metabolism for the synthesis of other non-essential amino acids that might be deficient and would therefore not give the expected result. 

The Results: A Remarkable Finding

At the end of the trial, of the 85 who took glycine, only 16 (18.8%, 12 of them belonging to the group that usually contracted infectious diseases more than once a year) had infections once, only during the first year of treatment, and much less severe and for a briefer period of time (3–4 days instead of the habitual 6–7 days prior to treatment), while of the 42 that did not take glycine, 39 of them contracted infections in the same way as before.

From this remarkable outcome, the scientists concluded that Glycine intake at a 10g/day dose (taken with a good balance of supporting amino acids), prevents the spread of viruses by strengthening the extracellular matrix barriers against their advance.

These multiple beneficial effects of glycine, coupled with its insufficient synthesis within the body, support the notion that it is a conditionally essential and also a functional amino acid for humans.

In regular diets, glycine is not adequately synthesized and so it should always be taken with a diet rich in protein to avoid its metabolic use synthesizing other non-essential amino acids that might be deficient in a low-protein diet, deviating glycine from its expected function and which would therefore not give the expected result.

Although legumes, fish, dairy products, and meat are some of the good sources of food, it is unreasonable to think the shortfall of 10g of glycine per day can be made up from the diet. The glycine content of most meats and seafoods is 1-2 grams per 100 grams of cooked food, eggs contain 0.4 grams per 100 grams of whole egg, and milk contains 0.08 grams per 100 grams of milk. This means that to get 10 grams from the diet would mean eating 5 steaks every day.

Studies have shown that consuming glycine in the form of a peptide (as in Glymax) results in a larger (9-12-fold vs 7-fold increase above fasting levels) and more rapid (30-45 vs 45-60 minutes) peak of glycine in the blood system. 

When peptides are given, they appear in the peripheral blood entirely as free glycine. The study showed that a given quantity of glycine is more rapidly absorbed into the blood when administered as a small peptide than as the free amino acid. 

Glymax hydrolyzed collagen peptide, produced by CollagenX, the leading Australian collagen company, has been specifically designed to contain over 20% more glycine than regular collagen, plus a rich and balanced profile of supporting amino acids. Supplementing your diet with Glymax increases the reinforcement potential of the body’s connective tissues, which may conceivably impede the advance of invasive agents (viruses or bacteria), thereby enhancing the capability of the immune system to repel such invasive agents.