Are Collagen Supplements the Cure-All We Think They Are? What Science Says

6 min read

It seems like it was just recently that bone broth was the craze, touted for boosting immunity, promoting gut health, and as the fountain of youth to protect skin from the common signs of aging. Most of the bone broth benefits were centered on one important component—collagen—and now that same component has become the go-to supplement on store shelves. Collagen peptides are everywhere, from the grocery store checkout line to the beauty counter at national store chains. With claims to enhance hair, skin and nails, and improve joint health and digestion, it’s hard to pass them up as the next big thing to add to your routine. But are these claims backed by the science?

Keep reading for what science says about collagen.

Let’s Start With Protein Basics

To understand collagen, you must first understand protein. Protein is found in a variety of foods including plants and animals. Amino acids are the building blocks of protein, nine of which are essential, meaning they must be consumed in the diet. Some sources of protein have all of the essential amino acids while others are missing one or more.

Protein quality can be assessed using a measurement known as the protein digestibility-corrected amino acid score (PDCAAS). This score is assigned to protein sources based on the amino acid profile and digestibility. As the score gets closer to 1.0, the digestibility improves and so does the essential amino acid profile. For example, dairy contains all nine essential amino acids and has a PDCAAS of 1.0. This score is important when evaluating quality sources of protein and is key to understanding collagen.

What is Collagen?

“Collagen is a protein that you find in connective tissue, as well as many organs, of animals,” explains Dr. Rachele Pojednic, assistant professor of Nutrition at Simmons College. It can be consumed in the diet, but it’s also synthesized in the body. “The creation of collagen,” she continues, “is many steps long and requires vitamin C.” Dr. Pojednic further explains that a deficiency of vitamin C leads to a condition called scurvy where the body cannot create enough collagen and therefore tissues start to breakdown. So, true to trend reporting, collagen is important stuff!

Is Collagen the Anti-Aging Secret Everyone Thinks It Is?

Collagen is a primary component of all tissues, including skin, and it plays a direct role in skin aging, i.e. wrinkles (or lack thereof!). As Dr. Pojednic mentioned, our bodies can make collagen, but a part of aging includes collagen breakdown and slowed production. So, to combat this natural process, many people are turning to collagen supplements.

“You’re probably familiar with injectable collagen that is used as a facial filler and lip plumper,” says Katie Andrews, registered dietitian and founder of Wellness by Katie. “The edible form of collagen is being marketed as a replacement to those painful and invasive injections, the theory being that if you consume the collagen it will produce younger looking skin, stronger nails, and even help relieve arthritis pain.”

Great, so if we eat collagen, we will produce more collagen, right? Not so fast. “The data we have on collagen supplements doesn’t really support that claim,” Dr. Pojednic says (while simultaneously crushing our anti-aging dreams). However, Katie provides a glimmer of hope for those looking to use collagen as an anti-aging supplement by pointing to a single study that found a connection between ingesting collagen and improved skin elasticity. “It is very challenging to ‘prove’ anti-aging claims, but a 2014 double-blind, placebo study (the gold standard!) did find that, in women ages 35 to 55 years, those who supplemented with collagen over a four-week period achieved greater skin elasticity than those in the placebo group,” she says.

But before you run to the closest shop to buy this supplement, Katie cautions that “there has been little other concrete scientific data to prove the benefits of ingestible collagen.” In other words, the evidence on these claims is limited.

What Actually Happens When You Eat Collagen

“We have good data to show that collagen can be absorbed, particularly hydrolyzed collagen found in supplements, but we don’t really have good data to show that it reassembles as collagen in the body,” says Dr. Podjednic. So, you can eat it, but there is no guarantee that it will do what you want it to do, which is make more collagen in the body.

Dr. Podjednic also points to an interesting fact: Naturally occurring collagen has a PDCAAS score of 0. This is primarily due to the fact that collagen does not contain all of the essential amino acids (it is lacking in tryptophan). And she says there are a few additional limiting factors of collagen supplements, beyond their lack of the essential amino acids. “You can’t guarantee these amino acids are going to be used to make new collagen in your body, because amino acids are used everywhere (there is some early and very small sample size studies that show athletes may benefit, but even that is very preliminary).”

So, Should You Take a Collagen Supplement?

We can’t lose sight of the basics when it comes to why we are taking supplements in the first place. Katie stresses the importance of remembering where collagen is naturally occurring. “Collagen is a protein, specifically a protein found in animal bones and tissues. Making your own soups or stocks with animal bones would be a significantly less expensive way to ingest collagen. In fact, if you are someone who includes meat in your diet, you are probably getting plenty of collagen already!”

While there are no known risks to taking collagen supplements, the Food and Drug Administration does not regulate supplements in the same way it does prescription medications, so there is no direct oversight that the supplement contains what it says it contains. The convenience of a supplement is difficult to pass up, but Dr. Pojednic recommends a more holistic view of the nutrients you’re consuming. “Grandma’s [soup] recipe is probably still the best and allows you to fully use (and honor) the animals you are eating,” she says.

The Bottom Line on Collagen

As with many trendy supplements, the scientific evidence to support collagen supplement intake will take a while to catch up to the hype—and there’s no promises that when it does, it will prove the claims. Dr. Pojednic bluntly points to the lack of science as a consideration when deciding to include a collagen supplement in your diet. “While there may be times when a supplement may work, we just don’t have the data to show the strength of the claims that are being made,” she says.

Katie makes a similar recommendation and stresses that the science is still new. “There is no clear mechanism that would explain why oral collagen supplements would have benefits for the skin beyond the amino acids we consume in our other protein-containing foods,” she says. “While there is no clear and present danger, I would still proceed with caution and maybe save your grocery dollars for something else.”


Still want to add that collagen to your diet? Try our smoothie recipes, featuring hydrolyzed collagen.

About The Author

Allison Knott

Allison Knott

Allison Knott, MS, RDN, CSSD is a registered dietitian and board certified specialist in sports nutrition based in New York City. Allison is an experienced nutrition consultant, speaker, and writer. She has a demonstrated history working in the food and beverage industry supporting corporate wellness initiatives. Allison has been featured in multiple television segments and in national publications including EatingWell, POPSUGAR, TIME Health, Shape, and Boston Magazine. In 2016, Allison started ANEWtrition, a consulting practice dedicated to delivering authentic, relatable, and consistent nutrition and wellness solutions.



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