When a person goes looking for information on “collagen” supplements, they often come out more confused than they went in. There are seemingly dozens of different varieties. There’s gelatin. There’s animal collagen. There’s marine collagen. Hydrolysate and peptides. And then there are all the “types” of collagen: type I, type II, type III, type IV, type V, and on down the line, each with unique properties and applications. Everyone seems to say something different.
What are you supposed to believe? How does a person make sense of it all? What are differences between them?
Let’s do that right now.
Gelatin is heat-treated collagenous animal tissue. Whether you’re a food manufacturer turning raw skin and bones into powdered gelatin for use in jello or a home cook slowly simmering beef knuckles in a pot on the stove to make rich bone broth that gelatinizes when cold, you are using heat to convert collagenous tissue into gelatin.
Gelatin is partially soluble in water. While its chemical structure prevents it from dissolving in cold or room temperature water, it does dissolve in hot water.
The health benefits of gelatin are equal to collagen. They have the same amino acid profile — lots of glycine, proline, hydroxyproline, alanine, lysine, and others. Inside the body, they’re all broken down into those same amino acids and utilized.
Gelatin is fantastic to have in the kitchen. While you can’t just mix it into cold drinks or throw it in a smoothie like you can collagen hydrolysate, you can use it to thicken pan sauces, enrich store bought stock and broth, and make healthy jello treats or luxurious gelatinous desserts.
Whenever I make a curry with coconut milk, as one of the final steps I whisk in a tablespoon or two of gelatin to thicken it up and give the curry that syrupy mouth feel. This is a game-changer, folks. Try it and you’ll see. This is also works in spaghetti sauce, soup, pretty much anything that includes liquid. Frying up a burger? Add some water to the pan, scrape up the fond (brown bits attached to the pan that are full of flavor), whisk in some gelatin, and reduce until it’s a thick sauce.
Collagen hydrolysate and peptides both mix readily into hot and cold liquids, and they give your body what it needs to assemble its own collagen. Hydrolysis is the process, peptides are the end product. Collagen hydrolysate refers to the process of using enzymes to break the peptide bonds to produce collagen peptides.
All collagen you see is animal collagen because there is no collagen that comes from non-animal sources. Plants do not contain collagen. I’m sure some startup is hard at work on producing lab-grown collagen, which ironically might be far less problematic than lab-grown steaks, but it isn’t available for purchase yet. It’s all animals.
What most people mean by “animal collagen” is land animal collagen—by far the most common type. Unless explicitly stated otherwise, the collagen you encounter on the market comes from land animals like cows and pigs.
Animal collagen is the most evolutionarily congruent type on the planet. Because for as long as we’ve been eating animals (well over a million years), we’ve been stripping them of their collagenous tissue for consumption. Even when the collagen wasn’t visible but rather entombed in weight-bearing bones, we would smash those bones with stones and boil them in ruminant stomachs to extract every last drop of fat and collagen.1
Don’t worry about any negative things you might hear about “animal collagen”; it’s what we’re made to eat. Heck, it’s what we’re made of.
Marine collagen is not extra-strong collagen derived from the battle-hardened sinews and bones of fallen heroes from the US Marine Corps. It is collagen derived from marine animals, usually fish but also invertebrates like squid, cuttlefish, and jellyfish.
Marketing types selling fish collagen claim that due to its lower molecular weight, marine collagen will be more bioavailable than collagen from land animals. This could be true. Fish collagen drawn from fish waste does have lower molecular weight than mammalian collagen, and that should lead to slightly higher bioavailability.2 But I wonder of its relevance.
One pro-marine collagen paper that makes a strong case for the use of marine collagen in wound repair, oral supplementation, and other medical applications does not mention increased bioavailability. It may be slightly more bioavailable—the lower the molecular weight, the more true that is—but I don’t think the effect is very meaningful. We know mammalian collagen is plenty bioavailable because most studies use collagen from cows or pigs, even if it’s a few dozen kilodaltons heavier.
Collagenous tissues are not uniform. Cartilage doesn’t look or feel like tendon, which doesn’t feel like skin. They’re all slightly different because there are different “types” of collagen that constitute them. Over two dozen, actually. But if we’re talking about supplementary or dietary collagen, there are three primary types we encounter.
Type I Collagen
Found in skin, bones, tendons, eyes, and many other tissues type I collagen constitutes almost 90% of the collagen in the body. That goes for humans but also cows and pigs and other mammals, meaning throughout the course of meat-eating human history, the vast majority of dietary collagen we’ve consumed has been type I collagen. As such, type I, though “boring and unexciting,” is the form of collagen we should be focusing on.
Type II Collagen
Cartilage is made of type II collagen. If you’re a gristle eater, an end-of-bone scraper, you’re getting type II collagen. You can also get a nice dose of type II collagen by eating the sternum of the chicken carcass—that’s the unctuous morsel of chewy cartilage lying at the end of the chest bone between the ribcages and one of my favorite parts of the chicken.
Type III Collagen
Type III collagen appears alongside type I in skin, bones, and also can be found in blood vessels and other hollow organs throughout the body. Most collagen supplements are type I with a bit of type III.
Types IV and V
Types IV and V aren’t as abundant in the body, and aren’t as widely used in supplements. You may see these in supplements as part of combination collagens. If you eat a varied diet, you’ll probably get enough in your food.
Focus on Types I, II, and III for skin, hair, joints, and other benefits you’re after. How much of each? To be quite honest, it’s not a big deal either way if you get more Type I than Type II or Type III. They’re all made up of the same basic amino acids, and your body knows what to do with them once they’re digested and assimilated. You don’t need to micromanage various collagen types as long as you’re eating some form of the collagen, whether through collagen peptides, gelatin, or gelatinous meats and bones.
I wish it were different. I wish you could get crazily specific effects by eating a lot of a specific collagen type. But, as far as my research shows, you can’t.
Thanks for reading, everyone. I hope it clears some things up and makes your decision a whole lot easier.
Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.