What is Collagen?
Collagen is a protein found ubiquitously throughout the human, and other mammals, bodies. Collagen is unique because it very resilient with great tensile strength. That is why we find collagen primarily in our tendons, ligaments, cartilage, and skin. Like other proteins, collagen is made up of amino acids – the building blocks of all proteins in essential bodily structures. Some of the key amino acids found in collagen are glycine, proline, and hydroxyproline. Collagen is found primarily in animal products, such as chicken and beef, including animal-sourced products, like bone broth or gelatin. However, there are at least 28 different kinds of collagen!
What Types of Collagen are Found in Supplements?
The most common types of collagen found in supplements are types I, II, III, and IV.
- Type I – Type I collagen is the most abundant in the human body. It is a very strong type of collagen with great elasticity. It is primarily found in tendons, ligaments, and skin. Its elastic properties allow the stretch that we can observe when pinching and pulling on our skin!
- Type II – Type II collagen is found in the cartilage that covers the ends of our bones. Where our individual bones come together and form joints, cartilage protects the bones from wearing each other down. Too little cartilage in our joints causing pain is known as osteoarthritis.
- Type III – The third type of collagen is a major component of bone and blood vessels and is the primary collagen found in bone broth. It usually accompanies Type I collagen in skin and joints.
- Type IV – Type IV collagen mostly populates the basal lamina of the extracellular matrix. The function of the extracellular matrix is to control and regulate cell signaling, which can also be referred to as cell-to-cell and intracellular communications, primarily with tissue growth and healing.
What are the Benefits of Collagen?
Collagen supplementation has been proposed to help with sorts of health-related matters. Some of its benefits are well-supported by the science and other are more hype than bona fide fact. Let’s review some of the most popular collagen claims.
Collagen Improves Joint Health, and Collagen Decreases Joint PainThis one is true. Collagen proteins in the human body are highly concentrated in the joints as several different tissues including bone, tendon, ligament, and cartilage. Hydrolyzed type II collagen supplementation has been found to be quite effective for reducing joint pain, theoretically by restoring and strengthening the tissues in joints. The good news is this is true for both young athletes playing college sports and older individuals with osteoarthristis and joint pain.
Collagen Heals the GutThis one is maybe true but very much exaggerated. Part of the problem with evaluating collagen and gut health is that the science isn’t settled on how to define what is a healthy or an unhealthy gut. We have some good indications, but there is still much to learn on the gut and the microbiome. That being said, low concentrations of collagen are associated with intestinal diseases, such as inflammatory bowel disease. Associated does not imply causation, so this should be taken with a huge grain of sea salt, but adding more collagen into the diet may restore some of the “missing” intestinal collagen. However, that may do nothing in terms of disease severity. We simply don’t know, and not enough research has looked at gut health in response to collagen supplementation.
Collagen Makes Hair, Skin, and Nails more BeautifulThis one actually seems like it could be true. Beneath the skin and other epithelial tissues, there is a lattice-pattern of collagen. As old skin cells die and fall off (which happens quite often), new skin cells rise to the surface. If these skin cells are rich with healthy and abundant collagen, they can help “lift” the valleys of fine lines, wrinkles and cellulite, but not fissures (creases; e.g., most males’ foreheads). One study has verified that UVB radiation damage is reduced with a collagen peptide supplement, and another found collagen to reduce skin water loss (moisturize), improve elasticity, and decrease wrinkle size vs. placebo.
Collagen Improves Metabolism and Body Composition, Decreases Toxicity, and “Protects”
We can’t definitively say that these claims are untrue, but we believe them to be unlikely, exaggerated, and/or nonspecific to collagen. These claims are mostly based on the fact that collagen contains certain amino acids, often glycine, because collagen supplements have not been studied for these effects. Glycine, and other amino acids, are abundant in many proteins – not just collagen. However, collagen provides some unique peptides, such as proline-hydroxyproline dipeptide, that are less common in other proteins, and this may actually be a major reason collagen supplements help with joint and skin health. Collagen may contain some other peptides that are of interest, but again, they have not been researched for the claims above. It is unlikely collagen is even as efficacious as most other proteins for improving metabolism and body composition, as that is largely predicated on the amino acid, leucine, but collagen is a low-leucine protein. Likewise, it cannot be ruled out that, versus another protein, a greater concentration of glycine, glutamine, or another amino acid present in collagen or collagen supplemented on a low-protein diet may help with some of these health matters.
How Cool is Collagen?
It’s almost too cool for school, but like any idolized high schooler, the stories are much more exciting than the reality. Collagen can help with joint pain and weakness. Collagen may also help improve skin health. However, it’s not a going to stir up any miracles and make your knee pain disappear instantly. Most studies examine collagen over long periods of time, such as 3-6 months. Long story short, collagen can HELP (just help) with joints and skin, but probably won’t do much for healing any other tissues.
- Pyun, H. B., Kim, M., Park, J., Sakai, Y., Numata, N., Shin, J. Y., ... & Hwang, J. K. (2012). Effects of collagen tripeptide supplement on photoaging and epidermal skin barrier in UVB-exposed hairless mice. Preventive nutrition and food science, 17(4), 245.
- Kim, J. K., Lee, J. H., Bae, I. H., Seo, D. B., & Lee, S. J. (2011). Beneficial effect of a collagen peptide supplement on the epidermal skin barrier. Korean Journal of Food Science and Technology, 43(4), 458-463.
- Clark, K. L., Sebastianelli, W., Flechsenhar, K. R., Aukermann, D. F., Meza, F., Millard, R. L., ... & Albert, A. (2008). 24-Week study on the use of collagen hydrolysate as a dietary supplement in athletes with activity-related joint pain. Current medical research and opinion, 24(5), 1485-1496.
- Schauss, A. G., Stenehjem, J., Park, J., Endres, J. R., & Clewell, A. (2012). Effect of the novel low molecular weight hydrolyzed chicken sternal cartilage extract, BioCell Collagen, on improving osteoarthritis-related symptoms: A randomized, double-blind, placebo-controlled trial. Journal of agricultural and food chemistry, 60(16), 4096-4101.
- Choi, S. Y., Ko, E. J., Lee, Y. H., Kim, B. G., Shin, H. J., Seo, D. B., ... & Kim, M. N. (2014). Effects of collagen tripeptide supplement on skin properties: A prospective, randomized, controlled study. Journal of Cosmetic and Laser Therapy, 16(3), 132-137