Written By: Josh Kreifels MS,CISSN, Dietetic Intern, University of Houston (@josh.kreifels)
Edited by: Brett Singer MS,RD,CSSD,LD with Memorial IRONMAN Sports Medicine Institute
- Collagen protein supplementation appears to be growing in popularity for sports performance and rehabilitation as well as its perceived health benefits
- Collagen supplementation may support collagen synthesis strengthening bone, tendons, and ligaments
- Collagen supplementation is unlikely to support muscle strength or growth due to its amino acid makeup
There has been growing popularity in the media regarding collagen supplementation for joint health. While evidence is limited, there is emerging research which indicates some potential benefits related to collagen supplementation and the health of bone, ligaments, and tendons.
To understand connective tissues’ role and opportunity to become compromised, it is important to first differentiate tendons from ligaments. Tendons attach muscles to bone and ligaments attach bone to bone. It is important for ligaments to be stiff and strong, however, tendons must be a bit more pliable in order to act as shock absorbers for muscle tissue.
Opportunities for injuries to both of these tissues is dependent on the structure and health of the attached tissues. Tendons may be damaged due to overly tight muscles creating excessive pull in the connective tissue or from trauma. Ligaments can be damaged primarily through excessive torque or trauma.
Interest in nutritional support for these tissues has become a focal point in athletic populations. The scientific evidence of collagen support through nutritional supplements is limited due to its limited history in sports rehabilitation.
There are numerous studies looking at the composition of connective tissue in vitro, however, extensive human studies are just not available. An in vitro study looking at a collagen supplement showed promising effects for reducing inflammation by suppressing inflammatory cytokines (1). The results from this study are important when considering the synthesis of collagen in human connective tissues.
What exactly is collagen? Collagen is a structural protein located in tendons, ligaments, skin and bones. These tissues are under significant stress and load on a daily basis which indicate a high demand for recovery and repair of these proteins. Tendons and ligaments are not well vascularized meaning injuries to these tissues can take significantly more time to heal than a muscle or bone injury.
In order to synthesize collagen, Vitamin C must be present which is why collagen powder is most effective when mixed with some fruit juice like orange juice that has higher quantities of Vitamin C. A dose of 15 g of Vitamin C enriched gelatin or hydrolyzed collagen similarly increased a plasma protein that is an indirect marker of collagen synthesis (2). The difference between the method of administrations did not statistically vary, it is just important to note that both tests contained vitamin C when measuring collagen synthesis.
Although nutritional status is a concern for preventing connective tissue injuries, age and gender are also significantly players in the health and integrity of these tissues. The collagen protein core in these connective tissues has a slow turn over rate making it difficult to completely isolate nutritional status as a cause for tendon and ligament injuries (3).
With growing population data, it is estimated that 80% of the population in their 80s have had some sort of connective tissue injury in their lifetime (3). This would suggest that age has a role on the integrity of the tissues due to the rate at which collagen is synthesized and turned over.
Another major factor on collagen strength and flexibility is gender. Connective tissue injuries are more prominent in women than in men which would indicate there is a hormone response on tendons and ligaments. During the beginning of a woman’s menstrual cycle, a surge of estrogen is released into circulation which actually causes the collagen matrix of these tissues to soften (3). This is an important physiological reaction during childbirth to allow the hips to soften in order to deliver a baby, but this softening of the connective tissue can put athletes at risk for serious injuries.
We now understand the complexity of collagen through nutrition, gender, and age, it is important to understand how collagen is synthesized and how to maximize an athlete’s health and return to play following an injury.
Collagen synthesis does not occur without stimulation of the connective tissue indicating a time sensitive effect of administration. The study previously mentioned gave the subjects the collagen plus vitamin C supplement in conjunction with a 6 minute low intensity exercise. Low intensity exercise is key to the delivery and synthesis of the key amino acids found in collagen to the connective tissue site (1).
Collagen is most effective when consumed thirty to sixty minutes prior to exercise (3). A randomized, double-blind, crossover study found 15 grams of gelatin consumed one hour before jumping rope for six minutes was able to significantly increase N-terminal peptide of pro-collagen 1 (PINP), a marker a bone formation (4).
In addition, collagen consumed after exercise or as a recovery supplement has not shown to be effective for muscle repair or tendon and ligament health.
Although there is currently limited research regarding benefits for athletes for return to play, there is some promising evidence that would suggest collagen supplementation to be effective for reducing injury time. Collagen supplementation seems to be under the umbrella of “it could help, but it certainly won’t cause harm” making it a potential tool for physical therapists and athletic trainers.
Athletes looking to supplement with collagen should ensure the product is approved for sport with a third party verification stamp. The research surrounding collagen nutritional products is limited as stated before, but there appears to be growing interest in its use to improve athletes’ return to competition.
Have questions? Please feel free to talk to an Athlete Training and Health Performance Coach or Brett Singer, Sports Dietitian MS, RD, CSSD, LD with the Memorial IRONMAN Sports Medicine Institute. Brett can be reached at firstname.lastname@example.org or can be found on Twitter at @bsinger10.
- Shakibaei M, Buhrmann C, Mobasheri A. Anti-inflammatory and anti-catabolic effects of TENDOACTIVE® on human tenocytes in vitro . Histology and Histopathology. 2011;26:1173-1185.
- Lis DM, Baar K. Effects of Different Vitamin C–Enriched Collagen Derivatives on Collagen Synthesis. International Journal of Sport Nutrition and Exercise Metabolism. 2019;29(5):526-531. doi:10.1123/ijsnem.2018-0385.
- Baar K. Minimizing Injury and Maximizing Return to Play: Lessons from Engineered Ligaments. Sports Medicine. 2017;47(S1):5-11. doi:10.1007/s40279-017-0719-x.
- Shaw G, Lee-Barthel A, Ross M, et al. Vitamin C-enriched gelatin supplementation prior to intermittent activity augments collagen synthesis. Am J Clin Nutr. 2017;105:136–43.