By Whitney Crouch, RDN, CLT
Collagen: It’s the most abundant structural protein in the body, and it’s more than just a hip, new trend popularised by different lifestyle personalities and brands. It takes the shape of a triple helix composed of the continuous repetitive motif, Gly-X-Y, where Gly is glycine, X is proline (Pro), and Y is hydroxyproline (Hyp).1 The latter two amino acids are specific to collagen structures. These protein building blocks make up the structure in skin, tendons, bones, and teeth and are integral in the health and maintenance of these structures over our lifetime.
Collagen is found naturally in the connective tissue of land animals such as humans, cows, and chickens, as well as some marine life, including fish. It makes up about 25% of our bodies’ protein content and is helpful in soft-tissue repair.2-3
People who consume animal protein regularly in their diet are consuming some collagen; however, muscle-meat proteins largely lack the rich proteins found in connective tissue. Individuals who routinely sip traditionally prepared bone broth benefit from the collagen extracted from the cartilaginous tissue used in the broth’s preparation. Furthermore, studies show that easily digested and absorbed forms of collagen, like those found in quality dietary supplements, can have an even greater rate of absorption than traditionally prepared foods.
Different types of collagen
Whether from animal or marine sources, all collagen comes from amino acids, the building blocks of protein in the body. Animal and marine collagens are constitutionally the same—that is, they’re made up of the same amino acids—however, animal sources have a larger quantity of some amino acids (proline and hydroxyproline, specifically).4
Research shows there are more than 28 different types of collagen, but the three most abundant are Types I, II, and III. These collagen types form the structural fibrils of tissues, while the others take part in the association of these fibrils with other tissues.2
What is the difference among hydrolyzed collagen, collagen peptides, and gelatin?
In addition to improving structural integrity and elasticity of the skin, the consumption of Types I and III collagen also improves skin’s ability to retain moisture and may fight UVB photodamage, which in turn promotes healthier and younger looking skin, according to studies.8-10
There is also mounting clinical evidence of collagen’s benefits in strengthening the collagenous structures of hair and nails. A study in the Journal of Investigative Dermatology reveals that collagen is strongly deposited in hair follicles, and the lack of collagen delays hair cycling and growth, suggesting that collagen could be a potential area warranting further investigation.11
In a six-month study looking at brittle nails, researchers found that daily supplementation with collagen resulted in increased nail growth and improved brittle nails in conjunction with a notable decrease in the frequency of broken nails.12
Inner strength and resilience
Additional evidence shows that supplementing with oral collagen stimulates collagenic tissue regeneration by increasing not only collagen synthesis, but minor components (glycosaminoglycans and hyaluronic acid) synthesis, as well. One such study used validated self-perception questionnaires to measure joint comfort and overall joint health in study subjects. After 90 days of intervention, 78% of subjects in the test group reported to have less joint discomfort, and more than 60% of the subjects agreed their joint health improved by increasing joint flexibility, mobility, and reducing joint stiffness. There were no statistically significant changes in the control group.13
As if the benefits of adequate dietary collagen seen in hair, skin, nails, and joints aren’t enough, there is also evidence to support collagen and gelatin’s role in bone health. In bone, approximately 95% is Type I collagen, providing viscoelastic strength, torsional stiffness, and load-bearing capacity. Type II collagen is also involved in bone formation, even though it is mainly found in cartilage.14
While the body of evidence around collagen supplementation continues to grow, the benefits of daily supplementation with collagen peptides (hydrolyzed collagen) can already be seen. There are uses for both gelatin and collagen peptides in cooking, baking, smoothies, and other means; however, the higher rate of digestion and bioavailability of the peptide form makes this supplement a great addition to anyone’s health routine.
Whitney Crouch, RDN, CLT
Whitney Crouch is a Registered Dietitian who received her undergraduate degree in Clinical Nutrition from the University of California, Davis. She has over 10 years of experience across multiple areas of dietetics, specializing in integrative and functional nutrition and food sensitivities. When she’s not creating educational programs or writing about nutrition, she’s spending time with her husband and young son. She’s often found running around the bay near her home with the family’s dog or in the kitchen cooking up new ideas to help her picky eater expand his palate.
Whitney Crouch is a paid consultant and guest writer for Metagenics.