Glycine: The Anti-Inflammatory Amino Acid Most Diets Are Missing

Most conversations about inflammation focus on "antioxidants", supplements, or eliminating entire food groups.

Far less attention is paid to the signaling role of amino acids, particularly glycine, one of the most metabolically important amino acids in the human body.

Glycine is an amino acid found in collagen, which is typically dismissed as a "non-essential" protein. But that label is misleading.

While the body can synthesize glycine, modern diets and metabolic stressors often create a gap between how much glycine we can make and how much we actually need.

That gap matters, especially when it comes to inflammation!

Collagen Structure: Why Glycine Matters

Collagen is built primarily from three amino acids:

• Glycine
• Proline
• Hydroxyproline

Glycine alone accounts for approximately one-third of collagen’s total amino acid content.

Structurally, glycine’s small size allows collagen fibers to pack tightly and maintain tensile strength. But its role doesn’t stop at building connective tissue.

Glycine is also a bioactive signaling molecule, particularly within the immune system.

Glycine as an Immune Signal, Not Just a Building Block

Glycine does more than contribute raw material for proteins. It actively communicates with immune cells. (ref, ref)

Research has shown that glycine activates glycine-gated chloride channels (GlyRs) expressed on immune cells, including macrophages. These channels are best known for their role in the nervous system, but they are also present in non-neuronal tissues, where they regulate cellular excitability.

When glycine binds to these receptors, chloride ions flow into the cell. This hyperpolarizes the cell membrane, making immune cells less excitable and reducing excessive inflammatory signaling. (ref)

In simple terms, glycine helps tell overactive immune cells to calm down.

Evidence for Glycine’s Anti-Inflammatory Effects

Across cell culture studies, animal models, and select human contexts, glycine has demonstrated consistent anti-inflammatory effects, including: (ref, ref, ref, ref, ref)

Chronic inflammation isn’t just an immune issue, it’s a metabolic one.

Activated immune cells are highly energy-demanding, drawing from the body’s limited energy supply.

When inflammation remains elevated, energy is diverted toward immune activity, and other systems are down-regulated as a result.

Overactive macrophages shift toward increased glycolytic flux, a less efficient way to produce energy that generates excess lactate. That lactate interferes with optimal mitochondrial function and contributes to insulin resistance and metabolic issues in surrounding tissues.

Chronic immune activation pulls energy away from other systems, lowering overall metabolic efficiency and systemic function.

Glycine helps apply the brake, not by shutting down the immune system, but by preventing unnecessary over-activation. 

These effects are not explained by antioxidant activity ('fighting free radicals'). Instead, they stem from electrophysiologic immune regulation, where immune cell signaling is directly modulated through ion channels.

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Immunomodulation, Not Immunosuppression

It’s important to distinguish between suppressing inflammation and regulating it.

Glycine does not eliminate inflammation, nor should it.

Inflammation is a necessary and protective response.

What glycine appears to do is modulate immune activity, reducing excessive or pathological activation while preserving normal immune defense.

This distinction matters. Immunomodulation supports resilience; immunosuppression compromises it.

What This Means for the Modern Diet

Modern diets are often heavily skewed toward muscle meat (for ex: chicken breasts and steaks), which are rich in the amino acid methionine but relatively low in glycine.

Historically, humans consumed the entire animal: skin, joints, tendons, connective tissue, and bones, which naturally balanced methionine intake with glycine.

Today, that balance is often lost: modern diets tend to emphasize muscle meat while leaving out the collagen-rich parts of the animal our ancestors relied on.

Over time, a chronic mismatch between methionine and glycine intake may increase metabolic strain, especially during periods of illness, stress, or inflammation when glycine demand rises.

Glycine-Rich Foods to Re-Incorporate

Restoring glycine intake doesn’t require eliminating muscle meat. It simply means including connective tissue regularly, especially during times of higher inflammatory load.

Traditional, glycine-rich foods include:

> Bone broth and slow-simmered soups
> Gelatin-rich cuts (skin, tendons, joints)
> Collagen-dense meats like: Beef, lamb, and pork shanks, Beef and pork cheeks
> Skin-on cuts
> Chicken wings, drumsticks, and gizzards

Bone Broth Isn’t Trendy, It Supports Your Physiology

Bone broth isn’t a wellness fad. It’s a glycine-rich, anti-inflammatory food that supports immune regulation and metabolic balance.

Your great-great grandmother didn’t drink bone broth for collagen peptides or gut protocols... She drank it because it was nourishing, restorative, and made full use of the animal!

As it turns out, physiology agrees.

These are the parts our ancestors valued, and modern food culture largely abandoned.

>> Interested in learning about the numerous other benefits of bone broth? Check out this blog post I wrote.

Ready to put this into practice? 

Stock up on glycine-rich, collagen-dense foods and build your next Nourish Food Club cart with cuts that support immune balance and recovery:

• Build-your-own bone broth box (ships separate since the collagen-rich broth is canned in glass)
• Beef Shanks
• Lamb Shanks
• Pork shanks (skinless or skin-on shanks)
• Chicken wings
• Chicken drumstick
• Chicken gizzards

• Beef cheeks and pork cheeks

Choose your favorite, and try to have at least one collagen source per day!

(Yes you can use collagen or gelatin powders. But it is always best to get your nutrients in through the whole-food matrix!)

These are the traditional cuts that naturally balance modern, muscle-meat-heavy diets, especially helpful during illness, stress, or recovery.