Collagen has exploded on to the functional food market in the form of powders, capsules, and additives that all promote smoother skin, shinier hair, healthier joints, and more lean muscle mass. To understand how collagen might work, we must first understand where it comes from and how our body uses it.
Collagen is a type of protein. The word collagen comes from the Greek work kolla, that means glue. True to its definition, collagen in the body is like an adhesive that holds many of the body’s tissues together. It is a major component in tendons, skin, ligaments, bones, and cartilage. Collagen in the body is synthesized from the protein that we eat and is the most abundant protein in the body.
There is no question that having ample collagen in our bodies is important. But the main question is, do collagen supplements directly translate into more collagen in the body?
All protein we consume is digested in the same way. Whether you are consuming a collagen shake, chicken breast, or bowl lentils, they are digested and broken down into individual amino acids in the body.
When we consume collagen, the body doesn’t magically recognize “this is collagen” and send it straight to your hair and joints. There is no evidence for that.
The argument exists that the body needs more of the specific amino acids present in collagen (glycine and proline) to make collagen, and this is true. But what supplement companies don’t want you to know is that you don’t need special foods to do these. These amino acids are found in abundance in the foods we eat every day, due in part to the abundance of collagen in the meat that we eat. You don’t need to ruin your morning coffee with powdered animal product to get in glycine and proline.
As far as single source protein sources go, collagen is one of the worst. It has a very poor amino acid profile and contains almost none of what we need to build muscle tissue. Whey, beef, soy, rice and pea are all far superior. Plant based eaters would do well to stick to more well-rounded plant-based proteins.
Are there studies that show a benefit to collagen consumption? Absolutely. But most of these studies suffer from a one or more limitations. Namely funding bias (they are funded by collagen companies), poor control (like daily protein not controlled), poor design, 24 hour food recall, small sample size, and no repeatability.
If the science ever catches up with the claimants, we will be the first to change our tune on this, as good scientists do. But right now, there is no evidence that supplementing collagen stands up to the claims made by supplement companies and there is an abundance of evidence that it is one of the worst single protein sources for regular consumption.
In a classic move by the supplement industry, companies have used a very thin veil of scientific evidence to convert a literal waste product of the food industry into a consumer product, sold in massive amounts thanks to very clever marketing and the fact that most people don’t know how protein works. This is hard news to hear if you are someone who has taken or is currently taking collagen protein for any of the above reasons. But now you know and you can use this information to inform your protein choice in the future.