Collagen: a Brief Review of the Research
Collagen is a supplement that has maintained popularity for quite some time.
With that, many glamorous claims have been made around the subject.
Some of these claims have good evidence backing them, others have good evidence refuting them.
In this article, I aim to breakdown and explain the research on collagen from a musculoskeletal health & fitness perspective.
I will touch on areas outside of this, but only briefly since that would imply leaving my area of expertise.
As always, if you have questions you feel are unanswered, you are welcome to comment below or email me at info@fitnesssimplified.org.
What is collagen?
To understand what collagen is, you should understand these definitions:
amino acid: individual constituents that are the building blocks of protein
Protein: long chain of amino acids bound together; like beads on a chain
Collagen is a protein comprised of a specific order & combination of amino acids. This specific combination leads it to have a hard, fiber-like structure.
With this characteristic, it is the largest component and provides structure to tendons, bones, skin, cartilage, and other connective tissue.
As such, collagen supplementation most commonly aims to alleviate this issue, among other problems to be discussed here soon.
Collagen supplementation’s effect on pain, injury, and rehabilitation, and quality of life
The research in this area is relatively early.
A recent study published in august 2023 studied this in active populations aged 40-65.
The researcher’s gave 0 (placebo), 10, or 20 grams of collagen per day to the subjects. The researchers then measured symptoms of pain from knee osteoarthritis, ease of activities of daily living, and and general measures of quality of life.
They found that 6 months into the intervention, the groups taking the collagen supplements experienced significant improvements compared to the group not taking collagen. 10 grams per day was shown to be better than 20 grams per day, and the effect was more pronounced in females than males.
The effect was also only shown in individuals participating in a rehabilitation program. In sedentary subjects, there was no improvement with collagen supplementation.
Another systematic review looked at collagen supplementation’s effect on recovery from joint injury & joint pain. 15 randomized control trials were included containing recreational athletes, elderly populations, and pre-menopausal women.
The researchers found improvements in joint pain both at rest and and during movement. They also found improved return-to-play time for young athletes who incurred ankle sprains, indicating collagen can help improve recovery from injury.
Conclusions & take home:
Collagen may be an effective intervention to improve joint pain and expedite recovery from injury occurring at tendons or ligaments.
The benefits of collagen are only experienced when its supplementation is accompanied by a rehabilitation program.
10 grams per day seems to be sufficient for men, but women may do better with 15-20 grams. More research is needed in the area of dosing.
Collagen supplementation’s effect on muscle growth, body composition, and recovery from exercise
With collagen being a protein, there is certainly an interest in how it can influence muscle growth, performance, and body composition overall.
So, let’s discuss what the research says.
This study from the American Journal of Clinical Nutrition compared collagen to whey protein in trained and untrained populations in regard to its ability to stimulate muscle protein synthesis (the process of muscle building).
The results showed that collagen supplementation has virtually no effect on increasing muscle protein synthesis, and whey protein is significantly better.
Why is this? because of one amino acid: leucine.
Leucine is the amino acid that provides the signal to your muscles to begin the process of building muscle.
Whey protein has ~4x the amount of leucine per gram than collagen protein does. As a result, whey is significantly better at simulating muscle growth.
Other research on muscle specifically has shown that collagen supplementation has no effect on muscle soreness, muscle recovery, muscle growth, or body composition overall.
Conclusions & take home:
Collagen supplementation has no effect for improving muscle or strength, improving body composition, or improving recovery by any measure.
If you are supplementing with collagen, it should NOT be included into your total protein intake for that day. It should be seen as separate.
Collagen supplementation’s effect on skin
As a disclaimer: we are now entering a topic that is a bit more out of my wheel-house.
Nonetheless, it is a topic that fascinates me, and the research seems to be promising; so let’s discuss.
This systematic review and meta-analysis included 19 different studies, totaling 1,125 participants aged 20-70.
The main findings showed that 3 months of collagen supplementation improved skin hydration, elasticity, and reduced wrinkles.
Why does this happen? As we lose collagen with aging, a result of this can be less structure in our skin; which leads to wrinkles. Sun exposure can also breakdown collagen, which leads to wrinkles and dehydration.
The role collagen serves here is to help replenish this broken down collagen due to aging and lifestyle.
Overall conclusions and take-homes
Given the data previously presented, collagen seems to be a supplement worth its while.
The main benefits seem to be improved health of non-muscle connective tissue including tendons, ligaments, bone, and skin.
The benefits of collagen on joint pain & injury are only in terms of enhancing the benefits of a rehabilitation program. In sedentary individuals, there is seemingly no benefit.
Despite collagen being a protein, it has virtually no benefit on stimulating muscle growth due to its low leucine level. Therefore, it should not be included in your daily protein intake.