Collagen, one of the most abundant proteins in the body, is also widely available as a supplement. Yet, questions remain about its effectiveness, particularly in supporting connective tissue and muscle growth.
Connective tissues play essential roles in the body, including protecting, supporting, and providing structure to various tissues and organs. Does collagen supplementation truly deliver benefits for connective tissue health?
On Nov. 20th, 2024, Dr. Layne Norton discussed a study conducted by a reputable research lab examining the link between collagen supplementation and connective tissue growth.
[Related: Better Understanding “Calories In, Calories Out” for Weight Loss (or Gain)]
Does Collagen Supplements Increase Connective Tissue Synthesis?
A recent study examining the effects of collagen peptide supplementation on connective tissue synthesis in resistance-trained young men employed an innovative method for measuring protein synthesis using heavy water, offering a perspective on long-term protein synthesis rates. (1)
Researchers have traditionally utilized labeled amino acids to measure protein synthesis, allowing for shorter monitoring periods. However, deuterated heavy water enables scientists to track protein synthesis over days or weeks, providing a more comprehensive understanding of longer-term synthesis rates.
The resistance-trained participants were given either a placebo or 15 grams of collagen peptides for one week. Despite collagen supplement companies sponsoring these studies, the results showed no significant differences in connective tissue synthesis between the placebo and collagen groups.
While Dr. Norton expressed skepticism regarding the overall benefits of collagen supplementation, he acknowledged randomized studies that suggest improvements in specific areas, such as skin elasticity and pain management. However, these studies don’t demonstrate notable increases in connective tissue synthesis. Norton supported this stance by referencing a second study published in Medicine & Science in Sports & Exercise, reinforcing his concerns about collagen’s touted benefits. (2)
“I give a lot of weight to these studies because they’re from very, very credible labs that have consistently shown over decades that they produce some of the highest quality research and protein metabolism,” Norton stated.
Collagen comprises about 33% glycine, meaning one in every three amino acids in its structure is glycine. Another 20% consists of proline and hydroxyproline. Supplementing with collagen, rich in these amino acids, can promote collagen synthesis. However, studies indicate that while supplementation increases glycine and proline levels in the blood, it doesn’t lead to measurable improvements in connective tissue synthesis.
How Collagen Supplementation Works
Many assume that taking collagen directly increases the collagen in their bodies, but this isn’t accurate. Dr. Norton clarifies that during digestion and metabolism, collagen is broken down and doesn’t enter the system in its pure form. “If it did, your cell wouldn’t even be able to take it up,” Norton explained.
Dr. Norton explained that the body breaks down collagen supplements through hydrolysis, reducing them into amino acids, much like any other protein. “When it enters the stomach, you have high concentrations of hydrochloric acid, which is going to cause that protein’s three-dimensional structure to begin to unfold; it’s called denaturation.”
When amino acids from collagen are broken down, the body absorbs them into the bloodstream, making them accessible to skin cells. However, according to Dr. Norton, this process doesn’t contribute to increased synthesis of connective tissue.
Dr. Norton concluded that while those who claim collagen supplements make them feel younger or experience fewer injuries are free to continue using them, he can’t recommend them. The current research fails to provide convincing evidence to support their effectiveness.
“When there is disagreement in the literature, I tend to default to the most tightly controlled well-done studies, and thus far, the most tightly controlled well-done studies show no effect,” Norton said. “I am airing more to the side of the very objective research outcomes showing no effect, and I can be swayed based on new evidence.”
According to Dr. Norton, collagen is the least effective protein supplement. Compared to other protein sources like whey, pea, egg, soy, plant, and wheat protein, collagen contains the lowest levels of amino acids. Additionally, it offers little to no benefit for muscle protein synthesis, making it a poor choice for those seeking to support muscle growth or recovery.
References
- Kirmse, M., Lottmann, T. M., Volk, N. R., de Marées, M., Holwerda, A. M., van Loon, L. J. C., & Platen, P. (2024). Collagen Peptide Supplementation during Training Does Not Further Increase Connective Tissue Protein Synthesis Rates. Medicine and science in sports and exercise, 10.1249/MSS.0000000000003519. Advance online publication. https://doi.org/10.1249/MSS.0000000000003519
- Aussieker, T., Hilkens, L., Holwerda, A. M., Fuchs, C. J., Houben, L. H. P., Senden, J. M., VAN Dijk, J. W., Snijders, T., & VAN Loon, L. J. C. (2023). Collagen Protein Ingestion during Recovery from Exercise Does Not Increase Muscle Connective Protein Synthesis Rates. Medicine and science in sports and exercise, 55(10), 1792–1802. https://doi.org/10.1249/MSS.0000000000003214
Featured image via Shutterstock/Miljan Zivkovic
