Collagen: The hidden Framework

When we think about what holds the human body together, we usually think of the skeleton. But bones are only part of the story. Throughout the body is an intricate extracellular matrix—a three-dimensional framework that surrounds our cells and helps give tissues their shape, strength, and organization. One of its most important structural proteins is collagen.

Collagen is an animal-structured protein that helps form skin, bone, cartilage, tendons, ligaments, fascia, blood vessels, discs and the structural framework of our organs. Different types of collagen are designed for different jobs.

While writing Aging Like a Fine Fiddle, I included collagen as one of the nutritional considerations for healthy aging. Recently, I met a lovely woman named Annette from the Health Bug Halifax health food store. She told me about a supplement called Natural Eggshell Membrane (NEM®) that customers were using for osteoarthritis with very positive feedback.  My first thought was... couldn't I simply eat the membrane from my eggs? But getting the 500mg of egg membrane the research suggests would require consuming numerous eggs (maybe a dozen), and the amount in each egg can vary considerably. That conversation inspired me to dig deeper into the research and write this article- to sort through the different types of collagen, their food sources and supplements to better understand what each may have to offer. 

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Collagen: One Family, Many Jobs

Scientists have identified more than 20 types of collagen. A handful make up most of the collagen we encounter in the body.

Type I is the most abundant and is prominent in skin, bone, tendons and ligaments.
Type II is particularly important in cartilage and is therefore of special interest when we're talking about joints.
Type III commonly accompanies Type I and is found in skin, blood vessels and internal organs.
Type IV forms specialized sheet-like networks called basement membranes that support and organize cells.
Type V occurs alongside Type I in many tissues and helps regulate the formation of collagen fibrils.
Type X is associated particularly with cartilage development and mineralization.

This is why the words "collagen supplement" don't tell us the whole story. The source, type, and—perhaps most importantly—how the collagen has been processed can make a substantial difference! 

Three Very Different Ways of Taking Collagen. 

1. Collagen Peptides: Building Materials
Hydrolyzed collagen has been broken into small peptides that are readily digested and absorbed.
Bovine collagen generally supplies predominantly Types I and III, while marine collagen is predominantly Type I.
These products provide collagen-derived peptides and amino acids—particularly glycine, proline and hydroxyproline—that the body can use as nutritional raw materials. Some collagen-derived peptides may also have biological signalling effects.
Bone broth fits primarily into this nutritional category.

Slow cooking extracts gelatin and collagen-derived proteins from connective tissues and bones. Once eaten, these proteins are digested rather than being transported intact from the soup directly into your knee.
Think of collagen peptides and bone broth primarily as raw materials for rebuilding.

2. UC-II: An Immune Message: Undenatured Type II collagen is quite different.
Rather than being hydrolyzed into small peptides, UC-II® retains aspects of the native three-dimensional structure of Type II collagen derived from chicken sternum cartilage.

And the amount used is surprisingly small—typically around 40 mg per day in clinical studies. Why so little? Because UC-II isn't intended primarily to provide bulk amino acids. Its proposed action involves something called oral tolerance.

The intestinal immune system constantly encounters proteins from food and decides which substances require an immune response and which should be tolerated. Small amounts of structurally intact Type II collagen appear to interact with gut-associated immune tissue and promote regulatory immune responses to Type II collagen.

In very simple terms, the message might be thought of as:
"You've encountered this protein through the gut. It is something to tolerate rather than attack."

That's an analogy rather than a literal description, but it helps explain antigen-specific oral tolerance.
This makes UC-II particularly interesting in the context of inflammatory joint processes because Type II collagen is a major structural protein of cartilage. So UC-II is less about supplying bricks and more about influencing the immune conversation around them.

3. NEM: The Natural Matrix. Then we have Natural Eggshell Membrane (NEM®).
If you've ever peeled a boiled egg, you've encountered eggshell membrane—the thin translucent layer immediately underneath the shell. Rather than isolating a single collagen molecule, NEM provides a naturally occurring connective-tissue matrix. Eggshell membrane contains collagens including Types I, V and X, along with other naturally occurring extracellular-matrix components, including glycosaminoglycans and hyaluronic-acid-related constituents.

That makes NEM quite different from both hydrolyzed collagen peptides and UC-II.
Clinical studies of standardized NEM preparations have commonly used approximately 500 mg per day, with some trials reporting improvements in joint pain or stiffness. The research base is still relatively modest, however, and larger independent studies would be valuable.

Think of NEM as providing more of a natural connective-tissue package rather than one isolated form of collagen.
Peptides vs. UC-II vs. NEM. The easiest way to remember the distinction is:

Collagen peptides/bone broth → BUILDING MATERIALS
Provide collagen-derived peptides and amino acids.
UC-II → IMMUNE SIGNAL
A tiny amount of undenatured Type II collagen used to encourage antigen-specific oral tolerance.
NEM → CONNECTIVE-TISSUE MATRIX
Eggshell membrane naturally provides several collagen types plus other extracellular-matrix components.
This also explains why taking one doesn't necessarily make the others redundant. They aren't simply three different brands of collagen powder. They represent different nutritional strategies.

What If You're Vegetarian?

Collagen itself is an animal protein, so traditional collagen, UC-II and NEM supplements are animal-derived.
But humans don't have to eat collagen to manufacture collagen.

Vegetarians can supply the necessary building blocks through adequate dietary protein—particularly foods providing glycine, proline and lysine—along with vitamin C, copper, zinc, iron and other nutrients involved in connective-tissue metabolism. Vitamin C is especially important because it is required for critical steps in collagen synthesis. Most products marketed as "vegan collagen" therefore aren't actually collagen. They are better described as collagen builders, supplying nutrients the body can use to manufacture its own collagen.

Feed the Framework.

Collagen isn't simply a beauty protein for smoother skin. It is woven throughout the architecture of the human body. Our cartilage, tendons, ligaments, bones, fascia, skin, blood vessels and organs depend upon collagen-containing matrices for their organization and mechanical properties. Our bodies continually remodel them. Good nutrition provides the raw materials. Movement and appropriate mechanical loading provide signals for adaptation. Vitamin C and other micronutrients support collagen synthesis. Targeted products such as collagen peptides, UC-II, or NEM may offer additional strategies, depending on what we are trying to accomplish.

Glucosamine sulphate, chondroitin sulphate, hyaluronic acid and other joint-support nutrients deserve their own discussion. But before adding everything in the supplement aisle, it helps to understand the foundation.

When you pick up something labelled collagen, ask a better question:
Am I taking building material, an immune signal, or a connective-tissue matrix?

The body depends not only upon its individual pieces, but upon the integrity of the framework that holds those pieces together. And much of that framework is collagen.  So nourish the framework, keep it moving, and give it what it needs to stay strong and resilient.  The goal is to age like a fine fiddle with beauty and grace. 



Dr. Dena Churchill
Author, Aging Like a Fine Fiddle
healthtruth.blog






Research & References

The following studies provide additional reading on the collagen preparations discussed in this article.
Natural Eggshell Membrane (NEM®)Ruff KJ, Winkler A, Jackson RW, DeVore DP, Ritz BW.
“Eggshell membrane in the treatment of pain and stiffness from osteoarthritis of the knee: a randomized, multicenter, double-blind, placebo-controlled clinical study.” Clinical Rheumatology. 2009;28(8):907–914.
DOI: 10.1007/s10067-009-1173-4.
In this randomized controlled trial, 67 people with knee osteoarthritis received either 500 mg of NEM daily or placebo for eight weeks. Improvements in pain and stiffness compared with placebo were reported at several time points, with some differences appearing by day 10. Overall WOMAC and function scores were not significantly different.
Read the NEM study on PubMed

Undenatured Type II Collagen (UC-II®)Lugo JP, Saiyed ZM, Lane NE.
“Efficacy and tolerability of an undenatured type II collagen supplement in modulating knee osteoarthritis symptoms: a multicenter randomized, double-blind, placebo-controlled study.” Nutrition Journal. 2016;15:14.
DOI: 10.1186/s12937-016-0130-8.
This study randomized 191 people with knee osteoarthritis to UC-II (40 mg/day), glucosamine hydrochloride plus chondroitin sulfate, or placebo for 180 days. At the end of the study, the UC-II group showed greater improvement in overall WOMAC scores than both placebo and the glucosamine/chondroitin group.
Read the UC-II study on PubMed

UC-II and Oral Tolerance.
A recent review of research on undenatured Type II collagen describes oral tolerance as a proposed immune-mediated mechanism for UC-II and identified eight clinical studies that met its inclusion criteria. The authors concluded that the evidence is promising but that larger, longer and better-powered trials are still needed.
Combining UC-II With Hydrolyzed Collagen Yuenyongviwat V, Anusitviwat C, Tuntarattanapong P, et al.
“Efficacy of combined undenatured type II collagen and hydrolyzed collagen supplementation in knee osteoarthritis: a randomized controlled trial.” Scientific Reports. 2025;15:32313.
DOI: 10.1038/s41598-025-17505-0.
This independent randomized, double-blind, placebo-controlled trial studied 68 people with knee osteoarthritis for 12 weeks. Both groups improved, but combining hydrolyzed collagen with UC-II did not produce significantly better pain or functional outcomes than placebo. The researchers noted that longer-term studies are warranted.
Read the 2025 collagen study on PubMed 

A Note About the Evidence: Nutritional research is rarely the final word. Different collagen preparations, doses, study populations and durations make direct comparisons difficult. Some of the earlier research on commercial collagen ingredients has also been industry-sponsored.

For that reason, I prefer to view these products as options to investigate rather than guarantees: establish good nutrition first, introduce one supplement at a time, give it a reasonable trial, and pay attention to measurable changes in pain, stiffness, and function.


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