A Better Kind of Protein?

When we talk about protein, the conversation often comes down to how many grams we consume. Protein has become something we count, compare and constantly aim to get more of.

But what if there is an equally interesting question: what kinds of protein are we eating?

Collagen is the most abundant protein in the human body. It is found in our skin, tendons, joints, bones, blood vessels and the tissues that support our organs. Yet it often gets overlooked when we talk about the protein in our diets.

We became curious about why. And about what happens when we start thinking of protein as more than just fuel for our muscles.

The body’s most abundant protein isn’t muscle protein

Collagen accounts for around 30 percent of the body’s total protein. It is primarily a structural protein. You could think of it as part of the body’s natural scaffolding.

There are many different types of collagen, each specialised for different tissues. Together, they help give the body strength, shape and support.

Skin: Collagen contributes to the skin’s structure and strength.
Tendons and ligaments: Collagen fibres help transmit forces and hold tissues together.
Joints and cartilage: Different types of collagen form an important part of cartilage.
Bones and teeth: Collagen provides an organic framework that works together with minerals.
Blood vessels and organs: Collagen forms part of the supporting tissue that gives structure to vessel walls and surrounding tissues.
The gut: Collagen is part of the connective tissue and extracellular matrix that support the intestinal lining and surrounding tissues.

For a useful overview, see Cleveland Clinic.

A very different amino acid profile

Proteins are made up of amino acids, but their proportions can vary considerably. Whey protein and muscle meat, for example, are relatively rich in essential amino acids that we need to obtain through food.

Collagen stands out in a different way. It is especially rich in glycine, proline and hydroxyproline. These amino acids help give collagen its distinctive structure, in which three chains twist together into a strong triple helix.

Glycine occurs at roughly every third position along collagen’s chains. That small detail says a great deal about how different collagen is from other proteins.

Collagen differs from complete protein sources, which provide all the essential amino acids in sufficient amounts. Its unusual amino acid profile is precisely what makes it an interesting complement to a varied diet.

Why does collagen get a poor reputation in fitness circles?

In strength training, proteins are often judged by how effectively they stimulate muscle protein synthesis. That makes sense when the goal is to build muscle.

For that specific purpose, whey protein is generally better suited than collagen. Collagen contains relatively little leucine and no tryptophan, which gives it a low score in traditional measures of protein quality.

But building muscle is only one of the many functions in which the body’s proteins play a role. Collagen’s amino acid profile tells a different story, with clear connections to skin, tendons, ligaments and other connective tissues.

Collagen peptides are also of interest in relation to tendons, ligaments, joints and skin. They invite us to take a broader view of protein rather than focusing on muscles alone.

A review in Nutrition Reviews explores this perspective: collagen and the adaptation and remodelling of connective tissue.

When we ate more of the whole animal

Historically, people made use of far more parts of an animal than the neatly trimmed cuts of meat commonly sold today. Bone broth, slow-cooked cuts rich in connective tissue, skin and other collagen-rich parts have long been part of food traditions around the world.

Muscle meat and connective tissue have different amino acid profiles. When we eat mostly fillets and other lean cuts, we get plenty of protein, but relatively less collagen than we would if collagen-rich parts were also on the menu.

At the same time, a growing share of many people’s protein intake comes from plant-based foods. Plant proteins contain no collagen, although they do provide amino acids that the body can use to make its own.

That raises an interesting question: has the composition of the protein we eat changed more than we tend to realise?

Could we benefit from more collagen in our diets?

Our bodies continually produce their own collagen from amino acids, with help from nutrients including vitamin C. As with other processes in the body, the food we eat helps provide the building blocks.

Glycine is particularly interesting. The body can make glycine itself, but researchers have also discussed whether its own production always meets the body’s many needs. Collagen is unusually rich in glycine, giving us another reason to pay attention to the kinds of protein we consume.

Studies of collagen peptides have, among other things, shown improvements in measures of skin hydration and elasticity. Joints, tendons and other connective tissues have also become interesting areas of collagen research.

This raises an intriguing thought: perhaps a thoughtful diet is not only about eating enough protein, but also about making room for proteins with different amino acid profiles.

And what does collagen have to do with the gut?

When we think about the gut, we often focus on bacteria, fibre and digestion. But the intestinal wall itself is a remarkably complex tissue, made up of cells, blood vessels, nerves and connective tissue.

Collagen is part of the extracellular matrix that gives tissues structure and helps anchor cells to their surroundings. Different types of collagen are found in the basement membranes and supporting tissues of the intestine.

The gut’s supporting tissue is not static. It is remodelled and renewed throughout life, and collagen is an important part of the structure that holds it together.

The connection between collagen, tissue structure and the gut’s normal architecture is fascinating in its own right. It is another reminder of the many jobs that proteins perform in our bodies.

Why we chose collagen for GO100

When we developed GO100, we wanted to create a functional bar with the gut in mind, using ingredients that complement each other.

Collagen became part of that choice. Not to compete with conventional protein bars for the highest possible protein content, but because we wanted this particular kind of protein and its distinctive amino acid profile.

In GO100, collagen is combined with resistant starch, fibre, MCT and carefully chosen ingredients that contribute flavour and texture. Each bar contains approximately 9.6 grams of protein in total.

Collagen plays one role. The resistant starch and fibre play others. It is the combination that makes GO100 what it is.

For more on the thinking behind the recipe, read our earlier article: We Developed GO100 with the Gut in Mind: Why We Chose Collagen.

Perhaps we should be asking a different question

Protein matters, and there are many good sources of it. But perhaps we oversimplify things when we judge every protein by the same measure.

Muscles have their needs. Connective tissues have their own structure. And the proteins in our food do not all have identical properties.

So is collagen a better kind of protein? Perhaps not better at everything. But different in ways that deserve much more attention.

Frequently asked questions about collagen and protein

Is collagen a protein?

Yes. Collagen is the most abundant protein in the human body and is found in skin, tendons, cartilage, bones and supporting tissues.

Is collagen inferior to whey protein?

Whey is generally a better choice for stimulating muscle protein synthesis. Collagen has a different amino acid profile and is also studied in relation to other tissues and functions.

Can the body make its own collagen?

Yes. The body makes collagen from amino acids and needs nutrients including vitamin C for the process. You do not have to consume collagen itself for your body to produce it.

Do plant proteins contain collagen?

No. Collagen is an animal-derived structural protein. Plant-based foods can, however, provide amino acids and other nutrients needed for the body’s own collagen production.