Let’s have a chit chat about collagen. Like many nutrients before it, collagen is having a MAJOR moment in the health and wellness industry. It seems almost every friend, relative, and celebrity is hopping on the collagen train for various reasons – primarily in regards to skin, hair, and joint health.
More recently, there has been buzz about the benefits that collagen might contribute to our gut health as well. Of course, as a digestive health dietitian, I got curious (and a tad bit skeptical), so I decided to dive into the research. Let’s start by first reviewing exactly what collagen is and the role it plays in the body before we jump into some of the claims about collagen in the gut!
What is collagen?
At its core, collagen is simply a protein. It is the primary type of protein that makes up our connective tissues such as skin, tendons, ligaments, cartilage, and even our internal organs. To put it very plainly, it’s what holds our bodies together. Collagen has a fiber-like structure which helps to make strong, stretchable tissues that bounce back from tension and pressure.
Collagen is made up of 19 different amino acids. A quick science lesson: amino acids are the tiny building blocks that make up all proteins. There are 20 amino acids that contribute to all types of protein – the only one missing from collagen is tryptophan, which is an essential amino acid (ie. we can’t make it ourselves and can only get it from foods).
Collagen in its whole form can’t be absorbed. Instead, collagen protein must be broken down into smaller fragments in order to get digested and absorbed into the bloodstream. This is why many collagen supplements come in a hydrolyzed form, which means that the longer chains of amino acids have already been broken down into something called peptides (small chains with 2-3 amino acids each). However, the human body can break down collagen on it’s own terms as well – so supplements aren’t the only way to access easy-to-absorb collagen peptides.
If it wasn’t already clear, collagen is an important building block in many of our organs and systems. It is the most abundant type of protein in the body and actually makes up more than 30% of the whole protein content of our bodies!
Collagen in the diet
Since collagen is a type of protein, we can get it from protein-rich foods. Some foods contain collagen in its immediate form, while other foods allow us to make collagen – ie. They contain the 19 amino acids that are required to produce collagen in the body. In short, some foods have collagen, while others help us make collagen.
Foods that contain collagen – meat, poultry, or fish with connective tissue and muscle, bone broth, egg whites.
Foods that support collagen production – various plant-based sources of protein such as nuts, seeds, legumes, and soy, as well as other animal protein sources like different cuts of meat, eggs and dairy products.
Really, any protein source can contribute to collagen production, as long as the body has access to the amino acids needed to build collagen. In addition to these protein sources, some other nutrients such as vitamin C and zinc play an important role in the production of collagen, so foods rich in these nutrients are also a worthwhile addition!
Current research about collagen in the gut
As we’ve established, collagen plays an important role in the human body, but can it actually help with our gut health? Many bloggers and influencers are totally convinced that collagen is THE thing for a healthy gut, but the research isn’t so clear at this point.
For starters, the term ‘healthy gut’ is entirely arbitrary – so let’s get more specific.
Those who are big believers in collagen supporting gut health, claim that collagen can:
- Cure leaky gut and gut permeability, therefore optimizing the immune function of the intestine
- Reduce inflammation in the gut
So is this true? While I can understand the theory behind some of these claims, theory is certainly not fact.
Collagen and leaky gut – what’s the evidence?
One of the primary theories is that some of the amino acids in collagen – particularly glycine and glutamine, will strengthen the lining of the gastrointestinal tract. By doing so, this would theoretically improve the tight junctions in our gut and prevent endotoxins from “leaking” into our bloodstreams through the gut walls. While that dramatic sentence makes it sound like collagen is a hero, there simply isn’t evidence to prove the amino acid profile of collagen can improve the lining of our intestines. And it certainly doesn’t provide insight into why collagen is considered the “best” compared to simply eating any other protein-containing foods like chicken or legumes.
So no, collagen doesn’t ‘cure’ leaky gut.
What about taking collagen for inflammation?
One study did find that serum collagen levels were lower in patients who had inflammatory bowel disease than healthy controls, but this is certainly not enough to assume that lack of collagen equals risk of IBD or any other inflammatory digestive disorders for that matter.
Another study (in rats) found that when the rats were chronically inflamed, it deteriorated collagen in their bodies. In this case, the inflammation came first, so we can’t assume that supplementing with collagen would reverse or prevent the inflammation. PLUS, we’re not rats. Again, simply NOT enough research to make any sort of claims about collagen helping with gut inflammation.
When we look deeper into the research, most of the studies used to support the above gut health collagen claims are very questionable, particularly because most of the evidence is coming from animal studies or in-vitro studies (ie. test tube experiments). I’ll say it one more time – we’re not rats! PLUS many of the studies on collagen in general have been funded by the collagen industry – which could be a red flag. While many studies funded by invested companies are still strong studies, it’s important to recognize the conflict of interest this could present and analyze this type of research closely.
Should you take a collagen supplement to support your gut?
No. It’s absolutely not necessary. When we consume collagen supplements, it’s like consuming any other protein – the collagen peptides get broken down into amino acids and just end up in the same amino acid pool that all of our other proteins do.
In fact, as mentioned above, collagen is actually missing one of our essential amino acids called tryptophan, so pinning all your hopes and dreams on collagen supplements means you might be missing out on other complete proteins (ie. protein sources that DO have all the essential amino acids we need). Collagen does not target specific areas like our gut, our skin, or our joints – it’s all just one mosh pit of amino acids regardless of whether it’s coming from a supplement or the foods we eat. I don’t know about you, but I’d rather spend my hard earned money on delicious food rather than supplements I don’t necessarily need!
At the end of the day, if your body needs collagen, it will make collagen from the amino acid pool. That being said, you do still need to consume an adequate amount of protein and a balanced diet to fill up the amino acid pool to begin with, so chat with a dietitian if you feel you need extra help with protein balance in your diet.
Collagen supplements don’t present a lot of risk and you’re certainly welcome to try them. However, there’s a lot more to research and understand before we can lock collagen peptides in as any kind of super-supplement!
FAQ’s about Collagen for Gut Health
Collagen is a type of protein that makes up connective tissues in the human body. It is made up of 19 different amino acids that help to maintain healthy tissues including skin, hair, tendons, ligaments, and the lining of the gut.
Foods that contain collagen include meat, poultry, or fish with connective tissue and muscle, as well as bone broth and egg whites. Other foods can support collagen production in the body including nuts, seeds, and legumes. See the full list here: Collagen Benefits for Gut Health