Like many of its fellow proteins, collagen takes on several roles in the human body.
Beyond its ever-popular cosmetic applications (hair, skin, and nails), this protein can help with joint pain, gut health, and even muscle building, among other uses.
We’ll explore each of these contexts throughout this category, but for now, consider this comprehensive guide a starting point.
Here we will define what collagen is, how it works, how it benefits the body, and more.
What Is Collagen?
The Building Block of Building Blocks
There’s a reason collagen is so abundant throughout mammals. Without it, we wouldn’t have strong, healthy skin.
Collagen is the most plentiful protein in the human body and most other mammals, comprising roughly a quarter of the entire protein content.
There are 28 known varieties of collagen, differing slightly in their internal structure as well as the larger structures they form in our tissues, with types I through IV being the most common.
Like all other proteins, this one is composed of amino acids.
According to this StatPearls entry by Lake Erie College of Osteopathic Medicine and Campbell University authors, the amino acid sequence required to synthesize collagen is glycine-proline-X or glycine-X-hydroxyproline, where X can be any of the other 17 amino acids.
Unlike globular proteins, which differ both in form and function, this protein is characterized by a tightly woven band of microfilaments, like a high-tensile rope.
Collagen is so ropelike, in fact, that clusters of this protein are often referred to as fibers.
Where Is Collagen Found?
This vital connective tissue building block lives in the matrix, but not the sci-fi dystopia we millennials keep struggling to explain to our Gen-Z friends.
No, we’re referring to the extracellular matrix, which is the space outside of our cell bodies (but still within the tissues they make up).
As detailed in-depth by this article from the University of California San Francisco, substances in the extracellular matrix exert several very important effects on nearby cells, including:
Providing the “essential physical scaffolding” for cell components
Contributing to the formation, differentiation, and maintenance of cells
Acting as a chemical buffer and water retainer
In other words, the extracellular matrix is kind of like a pit crew, staying just off the “track” that is the cellular makeup of the tissue and providing vital support services as needed.
For the most part, collagen shares this space with other proteins, water, and polysaccharides, which are clumps of sugar molecules.
How Does Collagen Work?
The primary function of this protein is to strengthen and support connective tissue, including those found in skin, bone, tendon, muscle, and more.
It’s a bit of a ‘meta’ analogy, but think of collagen as the ‘skeleton’ of skin and connective tissue; it provides a strong framework.
In this case and with many other proteins, the body naturally produces its own—which is one reason why well-crafted supplements are so safe—but as we age into our late 20s and early 30s, production begins to wane.
It’s no coincidence that early signs of aging like wrinkles can begin to show up at this time.
As foundational science and dozens of supporting studies have confirmed, collagen is what keeps the wrinkles at bay, promoting skin elasticity, hydration, and to a degree, resilience.
Beyond Cosmetic: Collagen’s Benefits Throughout the Body
Between the many types of collagen and the protein’s roles both outside of the cell (majority of well-known benefits) and inside the cell, it has been strongly implicated as beneficial for joint pain, gut health, muscle hypertrophy, and many, many other issues.
In some cases, researchers have noted beneficially altered production or uptake of pro-inflammatory substances, development and differentiation of lung tissues, and other varied functions.
It would take the better part of a textbook to go through its roles in every one of these cases, but we’ve outlined some of the most salient and concretely evidenced benefits of collagen below.
Without question, skin health benefits are the most well-known and solidly proven, so we’ll start there.
Collagen Can Improve Skin Health
A randomized study by Dermatest GmbH in Munster, Germany found that a “drinkable nutraceutical” product containing collagen, zinc, biotin, vitamin E, and a few other nutrients markedly improved several aspects of skin health among participants.
Half of the 72 total study participants—healthy women aged 35 or older—were given the test beverage, and the other half were given a placebo for the duration of the 12-week trial period.
The researchers then performed a series of assessments on both groups, including “corneometry (skin hydration), cutometry (elasticity),” and other tests that measured skin roughness and density.
After the trial period had concluded, researchers observed that the experimental group showed substantial improvements in all four of these skin health indicators as compared to placebo.
Furthermore, these benefits persisted throughout the four-week follow-up, indicating that the changes were both significant and well-supplemented by the body’s own collagen synthesis.
Another eye-opening finding published in the Journal of Drugs in Dermatology found that this foundational protein also shows promise in some wound healing applications.
In addition to the above-mentioned benefits (skin elasticity, etc.), this systematic review of eleven studies and 805 total participants found that collagen could safely and successfully treat pressure ulcers.
Another interesting observation that surfaced from the review is the consistency of anti-aging effects, and that the “anti-aging efficacy is proportional to collagen dipeptide content.”
As more applications for this hard-working protein are suggested (e.g., dermatitis), we hope to see more concrete evidence pointing to effectiveness, optimal dose range, safety, and so forth.
Collagen Supports Muscle Growth
It’s not too often that beauty vloggers and bodybuilders share the same affinity for supplements, but there’s a reason that collagen is bridging these two communities.
As mentioned, this protein isn’t just a key constituent of skin, but of skeletal muscle, tendons, and other connective tissues as well.
As the sports nutrition community is beginning to understand, this bodes well for building muscle and even preventing soreness.
On the muscle-building side, this finding from Ruhr University in Bochum, Germany found that supplementation with collagen peptides by young men (25 participants in their mid-twenties) over a twelve-week period enhanced overall body mass and fat-free mass when paired with strength training.
Both the placebo and the experimental group also increased in strength, thanks to the training, but this increase was slightly larger in the latter.
Interestingly, the researchers found that collagen supplementation caused “upregulation” (increase in uptake of a particular substance) of proteins that specifically served the “contractile fibers.”
In other words, this protein goes to work directly in your muscle tissue without increasing fat.
If you’re still reeling from that first post-lockdown visit to the gym, collagen may also help you recover from soreness, says this randomized trial from Newcastle University.
According to the results of the 24-participant trial, in which active men consumed either a collagen supplement or a placebo one week prior and two weeks after a physical fitness test (drop jumps), the experimental group experienced shorter bouts of less intense post-exercise soreness.
As a result, participants given the protein-rich supplement were able to recover their full jump height sooner than placebo participants.
It’s important to note that these effects were not clearly evident until 48 hours after the fitness test, so a bit of planning is required.
Ask any returning gym-goer about their soreness two to three days after a full leg workout, however, and they’ll assure you that it’s no picnic.
Collagen May Relieve Arthritis Pain and Stiffness
You don’t have to be a gym-goer or a mirror primper to benefit from hydrolyzed collagen supplements, because promising results are turning up in the area of osteoarthritis treatment.
The more than 50 million Americans suffering from rheumatic conditions like arthritis just may have a non-pharmaceutical option for staving off pain and improving their ability to get up and moving.
This review from the University of Illinois College of Medicine at Chicago that examined the results of seven studies and trials found that hydrolyzed collagen “stimulates a statistically significant increase in synthesis of extracellular matrix macromolecules by chondrocytes.”
In English, this means that this protein helps cells called chondrocytes to more efficiently do their job, which is to produce substances like glycoproteins and others that help to support healthy cartilage and swap out damaged molecules in the extracellular matrix that we covered earlier.
For osteoarthritis patients, preserving cartilage is crucial to preserving mobility and eliminating pain, so this is a potentially powerful opportunity.
Another review, this time from the Autonomous University of Nueve Leon, Mexico, breaks down the anti-arthritis action of collagen more specifically with the help of the WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) scale.
According to this review, collagen supplementation “revealed a significant decrease in the stiffness subscore (of the WOMAC)” as well as marked improvements in visual analog scores, which is when patients report their pain from 1-10.
Collagen May Help Gut Health
So far, the connections between collagen and its benefits for the above conditions/issues haven’t been too abstract, as these issues all clearly involve muscle, joint, and skin health, but did you know that this protein can help with inflammatory bowel disease?
Indeed, this study from the Ocean University of China found that collagen has an anti-IBD effect, but the science gets more than a little technical.
Basically, there’s a pro-inflammatory compound called tumor necrosis factor alpha, or TNF-α, that can harm the mucous lining surrounding our intestines in a way that promotes inflammatory bowel disease.
When the researchers applied collagen from the skin of Alaskan pollock to cells that were exposed to TNF-α, they discovered that the resulting destruction of proteins and other damages normally caused by this inflammatory compound were less severe than the control cells exposed to TNF-α (and not treated).
The extent to which this effect improves symptoms in real human subjects is a matter to be explored, hopefully in another study soon, but this study may provide a solid groundwork for collagen-based IBD therapeutics in the future.
Dietary Sources and Supplements
Never Fear, You Have Options
Vegeterians, vegans, carnivores, and the majority of us who are too busy to cook fresh meals every night can still get our collagen in—here’s how.
There are several ways to derive collagen from food and supplements.
First, the most efficient way to increase your dietary intake of this protein is to seek out “native” sources (i.e., to simply eat meat).
Foods With Collagen
As mentioned, this protein and several others are ubiquitous in the connective tissues of most mammals, so as long as the meat isn’t highly processed, you should be taking in a fair amount of connective tissue—sorry for the image, but it’s true.
Foods with collagen naturally built in, i.e., native sources, include pork, beef, chicken, fish, and some other seafood dishes.
Remember: the less processed, the better.
Another way to up your body’s production of collagen is to simply provide the “pieces,” i.e., the peptides made from amino acids, since our bodies are equipped to synthesize this protein.
There are dozens of foods (some of them plant-based) with high amounts of collagen building blocks, such as glycine, proline, and hydroxyproline, as well as the other amino acids (remember, there’s an “x” in the required amino acid sequence) used to make peptides.
These foods include legumes, sunflower seeds, pistachios, peanuts, and soy proteins, to name a few.
In order for this synthesis to occur successfully and efficiently, there are a few “cofactors” required, kind of like catalysts for chemical reactions.
Chief among these is vitamin C, which can be sourced from citrus fruits, strawberries, broccoli, peppers, potatoes, and many more.
In summary, look for minimally processed meat sources, other protein-rich foods with collagen building blocks (including vegan-safe options), and don’t forget about vitamin C.
If it’s difficult to up your intake through diet, supplements provide an excellent opportunity, because many of them come with other beneficial compounds included.
There are hydrolyzed collagen bars, powders, gummies, liquid supplements, and capsules widely available at top-tier supplement manufacturers across the country.
That said, in this market and all others, not all supplements and brands are created equal.
In addition to thoroughly researching the brand behind the product, it’s also important to make sure you can recognize when a supplement is geared towards the cosmetic side or the performance side.
For example, hyaluronic acid is typically used in conjunction with hydrolyzed collagen to better support skin health, where a performance supplement might include more protein/aminos, vitamin C, etc.
What Are Collagen Peptides?
With all this talk of hydrolyzed collagen, peptides, and so forth, it’s easy to get lost in the vernacular.
Collagen peptides and hydrolyzed collagen are essentially the same thing.
Peptides are strings of amino acids, like proteins, but much shorter and easier to digest.
Peptides are still functional, and can still be differentiated to the point where they mimic the effects of larger structures they’re named after.
The process of hydrolysis entails the application of a water molecule to break one or more chemical bonds in a given molecule.
This process is used in the case of collagen to form more easily digestible versions of the protein that are still biologically active, i.e., peptides.
What are collagen peptides doing in that supplement, you ask feeling snubbed?
They’re making it easier for you to digest and access this protein.
Is Collagen Safe?
The widely agreed upon consensus is that yes, collagen is very safe.
That said, there have been adverse collagen side effects, including:
Kidney problems (the disease process has to be already underway)
Feelings of fullness
These side effects are extremely rare, and almost always mild.
To learn more about the potential side effects of this protein, feel free to consult this article on that very subject.
With a balanced approach prioritizing exercise, dietary collagen intake and/or smart supplementation, anyone can benefit from this miraculous protein.
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TNI Editorial Team
We're health-conscious people who want to help others take control of their nutrition by offering spin-free, hype-free information that is medically accurate, confirmed by doctors.
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