If you’ve read any of my books, you’re probably already familiar with collagen. This is a type of protein found within our body and it is also something we can consume from food sources. 

First off, let’s define the term collagen. Collagen is a structural protein found in the body’s connective tissues, including skin, tendons, ligaments, and cartilage. It provides the framework that supports strength, elasticity, and firmness in tissues, making it essential for skin, joint, and bone health. It is also found in high amounts in certain organs, especially the uterus.

Collagen is the most common protein in the human body, accounting for about one third of the body’s total protein content. This protein is so prevalent because of its role in the repair and maintenance of structural tissues.

I’ll cover the benefits of collagen in more detail later in this article, but I want to get right to the main question we’re covering, which is whether or not you can count collagen toward your total protein intake. 

Does collagen count toward your protein intake?

This is a common question I receive about collagen. Technically speaking, collagen is an incomplete protein because it is lacking in one of the essential amino acids; namely, tryptophan. Given the lack of tryptophan, some have raised concerns that relying on collagen for protein intake might disrupt the balance of amino acids.

Luckily, a team of researchers have looked at this.

A 2019 study from the journal Nutrients looked at whether including collagen in the diet at levels that have been shown to have clinical benefits (which they defined as 2.5 to 15 g per day) would disrupt amino acid balance if it replaced a significant portion of the amino acid intake in people who consume adequate protein (their definition: consuming the recommended dietary allowance — or RDA — each day).

Now, many of you may not be aware that the RDA is set at a very low level; an amount that prevents overt deficiency, but may not be optimal. The RDA for protein for adult men is 56 g and non-pregnant adult women is 46 g per day. In other words, this is actually a very low protein intake!

This study found that including collagen in the diet resulted in no disruption in the balance between indispensable (essential) and dispensable (non essential) amino acids, when approximately one third of the total protein in the standard American diet was replaced with collagen peptides.

In other words, the protein in your diet could be about ⅓ from collagen and you wouldn’t run into any issues. This is true even though the protein intake of participants was so low (as I discuss in Real Food for Fertility, protein researchers have been trying to significantly increase the RDA for protein for decades).

This means that — yes — collagen does count toward your total protein intake, even though it is not a “complete” protein.

But remember, because collagen is not a complete protein, it should not be our sole source of protein. I recommend collagen as an adjunct to a diet that contains a variety of plant and animal sources. This ensures that you are not coming up short on any one amino acid (more on the importance of protein & specific amino acids in this article).

What are the benefits of consuming collagen?

Collagen has some unique benefits. Despite the lack of tryptophan in collagen, the other amino acids in it are essential for the repair and maintenance of structural tissues that help support both skin and bones — these include high concentrations of glycine, proline, and hydroxyproline.

• Glycine – Glycine is the most abundant amino acid in collagen, making up about one-third of its total amino acid content. Glycine is important for the formation of collagen’s triple-helix structure and is critical for maintaining collagen stability and strength. It is also a key component of our body’s major detoxification enzyme, glutathione.
• Proline – Proline is another key amino acid in collagen and helps provide structural integrity. It’s often found in a modified form, hydroxyproline, which is unique to collagen. 
• Hydroxyproline – This amino acid is a hydroxylated form of proline and is essential for collagen’s stability and durability. The presence of hydroxyproline in collagen distinguishes it from most other proteins.

Collagen also provides an array of other amino acids, including glutamine (again the only one entirely missing is tryptophan). Glutamine is important for maintaining gut integrity and supporting immune function, which indirectly supports overall tissue health and may benefit collagen-rich tissues by reducing inflammation and aiding recovery.

As one research study notes on the overall benefits of collagen: 

“Numerous studies have shown an improvement in skin elasticity, the recovery of lost cartilage tissue, reduced activity-related joint pain, strengthened tendons and ligaments, increased lean body mass in elderly men and premenopausal women, and increased bone mineral density in postmenopausal women.” – Nutrients, 2019

While you may be familiar with the typical highlighted benefits of collagen for skin, joint, and skeletal health, these amino acids also play important roles in a number of additional bodily functions, including detoxification, digestive health, and protection against inflammation and oxidative stress.

Benefits of collagen during pregnancy

Not only do protein requirements increase in pregnancy, but the quality of proteins becomes even more important. Protein quality —- as determined by the amino acid profile, digestibility, and availability for protein synthesis — is essential for optimal maternal health and fetal development. 

And this is where collagen shines, as it contains a number of both essential and non-essential amino acids that play an important role for both mom and baby.

More specifically, the requirement for a number of amino acids, including glycine and proline — both found in collagen — increases during pregnancy. So much so, that some of them, such as glycine, become “conditionally essential.” A conditionally essential amino acid is one that must be obtained from the diet during times of stress, illness, or growth when the body can’t produce enough to meet increased needs.

And the richest dietary source of glycine is: collagen.

Collagen and fetal development

Collagen supports fetal development by providing essential amino acids for processes such as methylation, cell differentiation, embryonic development, and fetal growth. 

Specifically, these amino acids support the formation of organs, connective tissues (such as tendons and cartilage), skin, blood vessels, and the skeletal system (bones and teeth). 

Collagen and maternal health during pregnancy

For the mother, the amino acids in collagen are just as important to support all the ongoing changes in the body including growing breasts, uterus, placenta, as well as the increased demands on the cardiovascular system and the stretching of skin. Most notably, by the end of pregnancy, collagen content in the uterus is 800% higher compared to pre-pregnancy.

Some of these amino acids (especially glycine) have even been shown to reduce blood pressure and blood sugar, as well as play a protective role against oxidative stress — a defining characteristic of preeclampsia. 

And as an added bonus, due to the role that collagen plays in skin health, adequate collagen intake can help support your skin’s ability to stretch without damage. Remember, bodily expansion is a natural part of pregnancy. There is limited scientific evidence — and a ton of anecdotal reports — that collagen can help prevent or lessen the appearance of stretch marks. There’s genetic and other factors at play with regards to the risk of stretch marks, but it’s certainly a potential benefit.

As you can see, higher collagen consumption during pregnancy can help meet the increasing demands for protein and specific amino acids. And don’t forget about postpartum! Protein needs are even higher during postpartum than they are during the third trimester of pregnancy.

Many of the amino acids in collagen are considered “non-essential”, but don’t let that word fool you. As I discuss in this article (and in Real Food for Fertility), newer research has shown that the concept of non-essential amino acids is scientifically unproven. There’s studies showing that many of these amino acids have their own unique biological functions and still must be obtained through diet for optimal health.

And nowadays we’re consuming far less collagen than we used to. In centuries past, animal foods were consumed nose-to-tail, including the parts that contain the highest proportion of collagen. Speaking of which, let’s dive into collagen-rich foods!

What foods are high in collagen?

Although collagen supplements often get a lot of attention, let’s not forget where collagen naturally comes from — and the traditional cooking methods that best break down/extract this essential protein.

If you think about what parts of the body that collagen benefits (skin, tendons, ligaments, cartilage, etc.), you can easily remember what food sources to include for increasing collagen in your diet — the connective tissues, skin and bones of animals.

And to be clear: collagen is only formed within animals, so animal foods are the only source of collagen. Any products claiming to contain “vegan collagen” are lying to you. There is no such thing!

Modern methods of meat processing that remove the bones, skin, and connective tissue of meats are throwing away some of the most nutrient-dense parts of the animal. In order to get the most collagen, these are the exact parts that you should be consuming. 

This is something that traditional cultures knew very well, as they consumed all parts of the animal (nose-to-tail), and made soups/stews from the tougher cuts, bones, and skin. It was probably more a matter of avoiding food waste than anything, but there are nutritional benefits to returning to these practices.

Here are some of the best food sources of collagen:

• Bone-in and tough cuts of meat (like bone-in pork shoulder to make pulled pork, beef shank or ox tail to make stew, or chuck roast to make pot roast)
• Ribs — short ribs, pork ribs, etc.
• Ground meat — oftentimes, the trim goes into ground meat, making it a surprisingly rich source of collagen!
• Skin-on, bone-in poultry (chicken/turkey thighs, wings, drumsticks, or a whole roasted bird — and save the bones to make bone broth later!) 
• Bone broth — include parts that are high in connective tissues (such as chicken feet, beef knuckles, necks, etc.) to increase collagen content of your broth
• Fish broth — use all parts of fish, including the head, bones, and skin
• Skin-on fatty fish (like salmon and cod) — pan-frying the skin until crispy is tasty!
• Pork rinds, cracklings, or chicharones (check the ingredients; it should be just pork skin and salt)

The next time you’re choosing meat, opt for bone-in, skin-on cuts, or those with intact connective tissue (like tougher cuts) to naturally boost your collagen intake. Tougher cuts of meat (as opposed to a fancy steak or pork chops) are often cheaper, more flavorful, and actually easier to cook! You get even more use out of your bone-in meats by saving the bones and any tough connective tissues after your first meal and using those leftovers to make broth (instead of tossing them like many people do). I keep a gallon-sized ziplock bag in my freezer for this exact purpose; when the bag is full, I make bone broth!. You can also purchase soup bones on their own, which are often fairly inexpensive from local farmers, or available from some online retailers. 

Once you get the hang of making your own broth (see here for a how-to) it’s fairly easy to include regularly. However, if you simply would rather have someone else do the work, FOND provides broths made from grass-fed beef or pasture-raised chicken with amazing flavor (use code LILY for 10% off sitewide). This is a super convenient option for early postpartum — and makes a great gift for new moms!

Connecting with local farmers may offer an opportunity for buying in bulk and help you build a relationship with your food. Or you can order high quality meat and have it delivered to your doorstep from companies like Wild Pastures or Butcher Box.

If you’re looking for meal inspiration, I include many recipes that feature tougher cuts of meat in my e-cookbook (such as beef short ribs and Mexican shredded beef), as well as in the recipe appendices of my other books.

Does everyone needs a collagen supplement?

Not necessarily. I’m a “food first” kind of dietitian, meaning if I can get nutrients readily from food, that’s always my first choice. 

Now, if I’m finding it hard to include a lot of collagen-rich foods in my diet — or if my collagen needs are higher than usual (injury, pregnancy, or early postpartum) — then I’m more likely to include collagen supplements. I also generally see no downsides with collagen supplementation, assuming you’re using a good quality brand that’s free of contaminants.

I haven’t eaten this way forever, and it’s an ongoing process to continuously source and cook foods that contain collagen. It does come more naturally and feel less intimidating over time, but if you are simply not able to fit these types of foods and recipes into your weekly rotation, or just want an added boost of collagen in your diet, a good quality collagen supplement could be helpful.

If you are looking for a quality collagen supplement source, FullWell makes my favorite. It has a clean flavor (virtually no flavor), it is sourced from 100% pasture-raised, grass-fed cattle, it’s third-party tested for pesticides (including glyphosate), top allergens, and heavy metals (Prop 65 compliant), and it’s pregnancy and breastfeeding safe. Use my affiliate link to get 20% off your purchase (new customers only). 

You can also check out my recommendations on Fullscript for some more options. Once you log in through my Fullscript link, go to the “my health” tab, click “community plans” and you’ll see categories for a huge array of supplements that I cover in my books. Collagen is one of those categories.

Some common questions about collagen supplements

Ok before I close out this article, let me answer some common questions

1. What’s the difference between gelatin and collagen?

The main difference between gelatin and collagen lies in their structure and how they’re processed/used in the kitchen. They are otherwise nutritionally equivalent.

• Collagen is the raw, intact protein found in connective tissues, bones, skin, and cartilage of animals. It has a strong, triple-helix structure that provides strength and elasticity to these tissues. When it comes to collagen supplements, the collagen is typically hydrolyzed (broken down into smaller peptides), making them highly digestible and easy to absorb. These smaller peptides are more bioavailable, meaning the body can use them quickly to support skin, joints, and other tissues. Collagen dissolves in liquids (it will not gel, unlike gelatin).
• Gelatin is a partially broken-down form of collagen. When collagen is cooked (e.g., by boiling bones into bone broth), it breaks down into gelatin, which has a less structured form and dissolves more easily in hot liquids. This is what gives gelatin its characteristic gel-like consistency when cooled. When you’ve made a particularly rich batch of bone broth, the liquid will solidify in the refrigerator (it looks like Jello!), but will reliquify upon heating.

By the way, if you’ve never tried making homemade gummies, this is your reminder to try it! The mango gummy bear recipe in my e-cookbook are a huge hit with my kids — and a great way to sneak in extra protein. My e-cookbook also includes a great anti-nausea gummy featuring lemon, honey, and ginger — it’s perfect for pregnancy-related nausea.

2. Does the source of collagen matter?

Great question. The 2019 study covered earlier in this article used 6 different collagen products (4 from pork, 1 from bovine, and 1 marine) and the results were essentially equivalent.

Although there is some research on specific collagen peptides and their bioactive properties, as a whole your choice of collagen product really depends on your preferences and budget.

For example, if you are pescatarian or choose to not consume beef or pork, you might prefer a marine collagen. The marine collagen from Vital Proteins, for example, is sourced from the skin and scales of wild caught Pacific cod from Alaska. The downside of marine collagen is that it’s often more expensive.

For those who eat beef or pork, collagen sourced from those animals is widely available. I personally prefer bovine collagen sourced from grass-fed cows.

Most collagen supplements are what’s called “hydrolyzed,” meaning they’ve been broken down into smaller peptides for easier absorption. Whether you’re consuming a collagen supplement in powder, liquid, or capsule form, bioavailability is the same. Don’t fall for deceptive marketing trying to claim otherwise.

That said, I prefer powdered collagen. It is not only the most economical option, but it makes it really easy to mix into other foods and liquids (think anything from coffee to baked goods or any meals that could use a protein boost!).  

Final thoughts on collagen as a protein source  

• Collagen, while not technically a complete protein, does not cause an amino acid imbalance — even when it makes up to 36% of total dietary protein. So yes, you can count it toward your total protein intake (yay!). Just remember, it shouldn’t be your sole source of protein.
• Consuming collagen offers many benefits for our skin, joint, and skeletal health, as well as for bodily functions such as detoxification, digestive health, and protection against oxidative stress.
• During pregnancy, collagen helps meet the increasing demands for protein and specific amino acids (like glycine and proline), which support the baby’s development as well as the mother’s physiological changes.
• When it comes to food, collagen is found in highest amounts in the connective tissues of animal foods, including skin, tendons, ligaments and cartilage (think skin-on, bone-in, and tougher cuts of meat). 
• Not everyone needs a collagen supplement, but if you are struggling to get enough collagen-rich foods in your diet, or if you like to boost your intake during times of increased needs (injury, pregnancy, or postpartum) then you could benefit from supplementation. 
• When it comes to the type of supplementation – I prefer powdered collagen (like this one), but any other form that is hydrolyzed is just as good and really up to personal preference (assuming you’re using a good quality brand that’s free of contaminants).

Let me know in the comments if you found this article helpful, and whether you currently — or plan to — include collagen as a part of your daily protein intake.

Until next time, 

Lily

PS – If you found this article helpful and are looking for more ways to incorporate collagen-rich foods into your weekly routine, I include a number of recipes in my e-cookbook that can help. Not only do they feature cuts of meat and cooking methods that can help boost collagen intake, but they won’t have you spending hours in the kitchen or shopping for obscure ingredients. Read the reviews and grab a copy here.

 

References

• Li, P., and G. Wu. “Roles of dietary glycine, proline, and hydroxyproline in collagen synthesis and animal growth.” Amino Acids 50(1) (2018): 29–38.
• Paul C, Leser S, Oesser S. Significant Amounts of Functional Collagen Peptides Can Be Incorporated in the Diet While Maintaining Indispensable Amino Acid Balance. Nutrients (2019) May 15;11(5):1079.
• Pencharz, P.B., et al. “Recent developments in understanding protein needs: how much and what kind should we eat?” Applied Physiology, Nutrition, and Metabolism 41(5) (2016): 577–580.
• Morrione, Thomas G, and Sam Seifter. “Alteration in the collagen content of the human uterus during pregnancy and postpartum involution.” The Journal of Experimental Medicine 115.2 (1962): 357-365.
• Friesen, Russell W et al. “Relationship of dimethylglycine, choline, and betaine with oxoproline in plasma of pregnant women and their newborn infants.” The Journal of Nutrition 137.12 (2007): 2641-2646.
• Aziz, Jazli, et al. “Molecular mechanisms of stress-responsive changes in collagen and elastin networks in skin.” Skin Pharmacology and Physiology 29.4 (2016): 190-203.