Nutrition Notes

Collagen Makes a Comeback

It’s hard to miss the exploding popularity of collagen proteins these days. Whether it’s in the form of homemade bone broth or collagen powders, collagen-rich items as foods or supplements are certainly experiencing a resurgence. Some people choose to get collagen by way of long-simmered animal bones (like our grandmothers did, and knowledgeable chefs still do), while others opt for adding collagen protein powder to coffee, tea, desserts, and other foods and beverages. Whether gotten the old-fashioned way or through the more modern method, dietary collagen can be helpful for supporting body collagen structures.

Why would you want to support collagen synthesis and maintenance? Well, collagen accounts for as much as 30-40% of all the protein in the human body, especially connective tissue, including blood vessels. Here’s how collagen stacks up as a percentage of the protein in the following tissues:

  • Skin: 75%
  • Tendons: 65-80%
  • Ligaments: 70%
  • Corneal tissue: 64%
  • Cartilage: 50%
  • Tooth dentin: 30% (That’s right; even your teeth have protein in them!)
  • Bone: 16% (Yep, bones are protein, too. Not just calcium!)
  • Muscle: 10-11%
  • Lung: 10% 

Compared to other proteins, collagen has a unique amino acid composition and a distinct role in human anatomy. The underlying structure of collagen is a braid—three protein strands woven together. This is what lends collagen its strength as well as its flexibility, which we see in some of the tissues above. We can stretch, run, do yoga, and our blood vessels expand and contract because of the structural properties of collagen.

Collagen proteins are rich in hydroxyproline. This is the amino acid proline, modified by adding an additional component. Hydroxyproline accounts for around 12% of the amino acids in collagen. Collagen also contains a high amount of the amino acid glycine (about 22%). Any complete dietary protein, such as meat, fish, dairy, poultry or seafood can provide these building blocks for collagen, but ingesting collagen itself ensures a pool of these critical raw materials. If you’re looking to support specific tissues in the body, it makes sense to consume those same tissues from animals in your diet, or products made from them. (Vegetarian and vegan diets also provide protein, of course. But in order to get the full complement of amino acids found in animal foods, vegetarian sources of protein should be varied and combined properly, as certain vegetarian sources are low in some of the essential amino acids.)

Many individuals—the elderly in particular—do not consume adequate protein. Even among people with a higher protein intake, unless nose-to-tail eating is emphasized, the richest sources of collagen—animal skins, bones, and tendons—are not typically part of the modern Western diet. (Tendon soups and stews are popular in East Asia.) Fortunately, you don’t need to babysit a stockpot on the back of your stove to reap the benefits of collagen in your diet. (Don’t forget, though, that you can make bone broth in a slow cooker or pressure cooker, so it’s pretty foolproof and requires very little hands-on time.)

Powdered collagen protein is now available, and it can be incorporated into shakes, smoothies, and other foods and beverages. (You can use it to make homemade jello, gummies, puddings, and other gelatin desserts.) Collagen protein powder is most often made from beef, but fish collagen is available for those who avoid beef for religious or cultural reasons. Collagen powder is a convenient way for us skittish North Americans to enjoy the benefits of these unique amino acids and protein fragments. Collagen powder is also an easy (and tasty) way to get higher doses of this kind of protein than you might be able to get from sipping broth or eating chicken skin.

You may come across the term “hydrolyzed” collagen peptides on containers of collagen powder. This means the proteins have been broken down into smaller pieces (called “peptides,” which are two or more amino acids string together). Hydrolysis means the proteins were broken down using water in the process: hydro (water); lysis (break apart). This makes them easier to digest and absorb, which might be especially helpful for people whose digestive function isn’t at its best, but who would likely benefit from increased protein, such as the elderly and people recovering from physical injury.

Collagen proteins are helpful for a number of issues. Because of its primary structural role in certain tissues, collagen has been shown to help increase bone mineral density, support healthy blood pressure, improve nail growth and the appearance of skin wrinkles, and reduce some of the symptoms associated with osteoarthritis.



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  2. König D, Oesser S, Scharla S, Zdzieblik D, Gollhofer A. Specific Collagen Peptides Improve Bone Mineral Density and Bone Markers in Postmenopausal Women—A Randomized Controlled Study. Nutrients. 2018;10(1):97.
  3. Hexsel D, Zague V, Schunck M et al. Oral supplementation with specific bioactive collagen peptides improves nail growth and reduces symptoms of brittle nails. J Cosmet Dermatol. 2017 Dec;16(4):520-526.
  4. Proksch E, Schunck M, Zague V et al. Oral intake of specific bioactive collagen peptides reduces skin wrinkles and increases dermal matrix synthesis. Skin Pharmacol Physiol. 2014;27(3):113-9.