Research & Education

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 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.

Compared to other proteins, collagen has a unique amino acid composition and a distinct role in human anatomy. Collagen proteins are rich in the modified amino acid hydroxyproline (which accounts for approximately 12% of the amino acids in collagen), and they have an unusually high content of glycine and proline (around 22% and 13%, respectively). Any complete protein can provide these building blocks for collagen, but ingesting collagen itself ensures a pool of these critical raw materials. Collagen is a more concentrated source of these, especially hydroxyproline, and as such, it may be a more effective choice when the goal is related to collagen as a structural protein, such as in supporting the strength of bones, tendons and cartilage, as well as the appearance and underlying health of skin.

Collagen accounts for as much as 30-40% of the body’s total protein, 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%
  • Bone: 16%
  • Muscle: 10-11%
  • Lung: 10% 

The amino acid and peptide compositions of dietary collagens are very similar to those in human collagens, making dietary collagen peptides ideal for supporting body collagen turnover and renewal.

Many individuals—the elderly in particular—do not consume adequate protein. Even among those with a higher protein intake, 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.) Since collagen powder can be incorporated into shakes, smoothies, and other foods and beverages, it’s a convenient way for us culinarily squeamish North Americans to enjoy the benefits of these amino acids and peptides. Using collagen powders is also an easy way to titrate to higher doses when appropriate.

The benefits of collagen peptides are explained by the fact that they are absorbed and transported to cells in various amino acid sequences and lengths. Endogenously produced collagen peptides are viewed as signals for stimulating repair or renewal of connective tissues. Diet-derived collagen peptides act in concert with endogenous peptides to enhance this type of signaling. Collagen peptides are eventually broken down to individual amino acids inside cells, providing building blocks for new collagen synthesis. Cofactors such as vitamin C, silicon, iron, sulfur and copper are crucial for stabilizing newly synthesized pro-collagens, a process that converts them to tissue-usable collagens.

Vitamin C is an interesting issue with regard to collagen synthesis. It’s an essential cofactor in prolyl and lysyl hydroxylase enzymes, which create hydroxyproline and hydroxylysine, respectively. With the growing numbers of people adopting low-carb or ketogenic diets, what about vitamin C? Well, for starters, even without orange juice or grapefruit, low carbers and keto dieters can get plenty of vitamin C from low-carb vegetables, such as broccoli and bell peppers. But what about the growing popularity of all-meat diets? Even there, there might be more than enough vitamin C to go around. Let’s not forget that glucose competes with vitamin C for cellular uptake, so people consuming a high-carb diet might have a greater requirement for vitamin C than those who consume very low to no carbohydrates. Plus, it’s possible that when people consume more pre-formed collagen peptides, they may need less vitamin C because they’re getting hydroxyproline and hydroxylysine directly. 

Future posts will dive more deeply into specific roles for collagen peptides, including maintenance of lean muscle mass, increasing bone mineral density, supporting healthy blood pressure, improving nail growth and the appearance of skin wrinkles, and reducing symptoms of osteoarthritis.

By Amy Berger, MS, CNS