Recently, collagen protein has garnered quite a bit of attention. Where whey, casein, soy, and maybe a few other proteins were the ones available, you now usually find collagen protein as well. In addition, several studies over the last few years have demonstrated actual increases in fat free mass following collagen protein supplementation, comparable to that of whey protein.
This increase in fat free mass, is it muscle protein? Probably not. Collagen (and gelatin) protein does not provide enough of the essential amino acids to support a robust increase in muscle protein synthesis. Remember that “fat free mass” is everything in the body except fat. This includes the organs and cartilage and connective tissue.
This isn’t a bad thing in and of itself. Even if you shouldn’t expect massive gains in muscle from collagen protein, increasing collagen synthesis in cartilage and connective tissue could help prevent and recover from joint injuries. That is always a welcome thing for an athlete.
A new study provides support for this mechanism. Active males ingested various sources of collagen and dairy proteins, after which the researchers measured the amino acid levels in their blood. The proteins were from collagen powder in the form of several types of gelatin, two types of casein (calcium caseinate amd hydrolysed casein), a liquid collagen supplement, and bone broth, a food that contains plenty of collagen.
Ingestion of all the proteins resulted in pretty similar increases in plasma amino acids, with two notable exceptions:
- The dairy proteins raised blood leucine levels more. Leucine is the trigger for muscle protein synthesis, and the fact that milk proteins contain as much leucine as they do is the number one reason they are so anabolic and suitable for building muscle.
- The bone broth and the collagen and gelatin supplements increased the glycine levels in the blood of the subjects significantly more instead. Previous research has demonstrated that glycine is intricately involved in collagen synthesis.
This means that increased glycine in the diet could be a way to also increase collagen synthesis and cartilage regeneration. This in turn might very well be good for the joints, something the athletic population could make good use of.
In summary, stick to other proteins if you want to build muscle. However, collagen and gelatin are probably good for more than making Jell-O. They could help protect your joints, which sounds good to me. Not as good as a big bowl of cherry Jell-O, but still.
- Plasma Amino Acid Concentrations After the Ingestion of Dairy and Collagen Proteins, in Healthy Active Males. Front. Nutr., 15 October 2019.
- High glycine concentration increases collagen synthesis by articular chondrocytes in vitro: acute glycine deficiency could be an important cause of osteoarthritis. Amino Acids. 2018; 50(10): 1357–1365.
- Collagen peptide supplementation in combination with resistance training improves body composition and increases muscle strength in elderly sarcopenic men: a randomised controlled trial. Br J Nutr. 2015 Oct 28; 114(8): 1237–1245.
- Specific Collagen Peptides in Combination with Resistance Training Improve Body Composition and Regional Muscle Strength in Premenopausal Women: A Randomized Controlled Trial. Nutrients 2019, 11(4), 892.