For years, the bodybuilding, protein-gorging community has maligned collagen for its inessentiality  and lack of input into the muscle-protein synthesis process. From their perspective, it sort of makes sense. Why bother with “low quality” protein like gelatin/collagen when you can pound the whey, eat the meat, and focus on other sources of the essential amino acids directly involved in building muscle ?
Except the research is showing that these “nonessential” proteins are actually pretty darn useful.
A while back, I suffered an Achilles injury during of one of my Ultimate Frisbee  matches. In my attempt to speed recovery time, I did some research and started supplementing with collagen . The results, in my personal n=1 experiment, were pretty dramatic. Once I added collagen to the mix, my healing kicked into overdrive. As I’ve dug deeper into this topic to uncover the many benefits dietary collagen can bestow upon us, I’m convinced collagen/gelatin is an essential part of the human diet. And yes, even—or especially—bodybuilders, power lifters, and other athletes concerned with performance, muscles, and optimizing swoleness can benefit from eating more collagen . But why?
1. We don’t make enough glycine to cover our body’s needs
Most people view amino acids in one of two ways: either they’re essential, meaning our bodies can’t synthesize them, or they’re inessential, meaning our bodies can. In actuality, there’s a third category: amino acids can be conditionally essential. Glycine, the primary amino acid in collagen, is synthesized from the amino acid serine to the tune of 3 grams per day. That’s not nearly enough. The human body requires at least 10 grams per day for basic metabolic processes , so we’re looking at an average daily deficit of 7 grams that we need to make up for through diet. Even more in disease states that disrupt glycine synthesis, like rheumatoid arthritis .
2. We’re wasting half the animal otherwise
The average cow is half muscle meat and half “other stuff.” Most people only eat the muscle meat and ignore the other stuff, which includes bones, connective tissue, cartilage, tendons, and other collagenous material. The other stuff ends up in pet food or used by other industries, but we could be eating it, getting healthier, and wasting less food in the process.
3. It balances out our meat intake
The more meat we eat, the more glycine our bodies utilize. This has been shown in rodent studies. Rats on high methionine (the amino acid most prevalent in muscle meat) diets die earlier than rats on low methionine diets. Keeping the methionine high while adding glycine, though, abolishes the reduced longevity . In human terms, this would be like continuing to eat muscle meat while adding in collagen or gelatinous meats. If the same holds true in humans, it means low-animal protein diets aren’t necessary to live longer, healthy lives. It means all those atrophied calorie restriction folks are doing it wrong. They could be eating meat—deriving the “short-term” benefits like increased lean mass, better athletic performance, and lower fat mass—and living long, healthy lives.
4. It might explain the “meat-disease” links
We like meat around here. We make no bones  about it. And whenever a questionable observation study comes out claiming a link between meat and disease or death, we’re quick to show why it’s spurious or explained by variables the researchers failed to control for. But there’s another possibility: what if there is a connection between meat and certain diseases, like diabetes, and eating collagen is the key to severing that connection? In one recent study , the relationship between red meat and diabetes was abolished after controlling for low-glycine status. People with low glycine levels and high meat intakes were more likely to have diabetes; people with higher glycine levels could have higher meat intakes without any issues. In another study, low circulating levels of glycine predicted diabetes risk . It may very well be that the way most people eat meat in developed countries—eating chicken breasts over chicken wings and skin, lean steak over oxtails and shanks, muscle meat over bones, skin, and tendons—is unhealthy. Increasing your collagen, then, could balance out the meat intake.
5. It’s protein-sparing
Eating gelatin reduces the amount of muscle meat required to maintain muscle mass and perform your regular protein-related physiological functions. We don’t need so much of the expensive muscle protein when we’re eating enough collagenous materials. Most recently , elderly men who supplemented with collagen experienced greater anabolic responses to resistance training than elderly men who didn’t take any collagen. Note: this was collagen, not whey, or beef, or eggs, or any of the other rich sources of essential amino acids normally associated with muscle building. The increased dietary collagen was likely sparing the amount of “meat protein” used for daily maintenance and allowing its greater utilization for putting on lean muscle mass.
6. It improves sleep quality
One of my go-to “sleep hacks ” is a big mug of bone broth about an hour before bed. It always knocks me out (in a good, non-narcotic way). And according to research, I’m not making this up or suffering from placebo. Human studies show that 3 grams of glycine taken before bed increases the quality of your sleep  and reduces daytime sleepiness following sleep restriction .
7. It’s good for your joints
Remember that study showing how we need at least 10 grams of glycine each day for basic metabolic processes? One of those processes is the maintenance of the collagen in our body (the most abundant protein we carry, in fact). Collagen is everywhere through the human body, but it concentrates where joints meet and in the connective tissue binding us together. Those 10 grams of glycine is just for maintenance, not repair after catastrophic injury or recovery from intense loading. If you’re a heavy exerciser or are recovering from joint damage, supplementary collagen /gelatin/glycine will improve your resilience. One recent study  found that a glcyine-rich diet made the Achilles’ tendon stronger and more resistant to rupture in rats, increasing tendon remodeling in response to injury faster than rats on a low-glcyine diet. A 2008 human study  found that giving collagen hydrolysate supplements reduced pain in athletes complaining of joint pain.
8. It’s good for your skin
Your face is made of collagen. Your underarms are made of collagen. All the problematic swathes of skin liable to descend into wrinkly parchment are made of collagen. Collagen provides body and bounce. Just like it keeps the integrity in a bowl of jello, collagen keeps skin buoyant. And when collagen levels in the skin drop, the skin droops . The studies bear this out:
- In middle-aged Korean women , a collagen supplement (6 g per day) reduced skin cracking and increased serum collagen.
- Collagen peptides reduced wrinkling .
- Collagen improved skin elasticity .
And since the apparent age of your face is actually a good barometer of your longevity , increasing collagen consumption to maintain skin appearance may be way more than just a cosmetic intervention.
9. It improves wound healing
Makes sense, right? Our collagen requirements increase during wound healing (which involves laying down collagen to build new tissue ), so a little extra in the diet can make a big difference. In patients recovering from ulcers, collagen supplementation sped up healing time . Some clinicians are even packing collagen directly into the wound dressing  to speed up the healing process.
10. It enhances cooking
The foundation of many classic cuisines and dishes is gelatin-rich bone and meat broth. Soups, sauces, demi glace, curries, Jell-o Americana Egg Custard. Go to a high-end French restaurant and everything you eat—except maybe the dessert—will involve gelatin-rich stock. I’ve even used straight gelatin powder to enrich sauces and curries.
Okay, okay. Sisson, I’m convinced. How do I get more collagen in my life? Here are a few ways.
Eat gelatinous meats. Many meats are low in collagen, but not all. Shanks, necks, feet, cheeks, oxtails, ribs, and all the other cuts that take extra time in the slow cooker to become tender are high in collagen. Favor these meats instead of yet another chicken breast.
Clean your bones. You know those crunchy caps at the end of chicken drumsticks? That’s cartilage, a big whopping dose of concentrated collagen. Eat it.
Eat skin. Skin is almost pure collagen. Eat it, and eat the discarded skin from finicky dinner mates.
Drink bone broth. Bone broth is trendy right now, and for good reason; it’s a rich source of collagen. Bone broth is simple to make  but takes valuable time. If you can’t do it yourself, there’s a budding bone broth industry more than willing to ship frozen or shelf-stable broth to your door.
Use powdered gelatin. I always keep a can around. You don’t have to make jello with it. My favorite use is a quick 10-minute Thai curry: toast the spices and curry powder in coconut oil, add coconut milk, reduce, and whisk in a couple tablespoons of gelatin powder to obtain the desired texture and mouth feel. Delicious and a huge dose of collagen.
Use collagen hydrolysate. (Update) Following my Achilles injury, I was moved to create my own collagen powder with 20 grams of collagen protein (more collagen than 2 cups of bone broth), that’s now available for purchase .
Eat Primal Kitchen bars. Each of my PRIMAL KITCHEN® bars  contains 8 grams of pure collagen from grass-fed cows  (it’s what gives the bar its unctuous chewiness). With collagen being about 33% glycine, that’s over 2.6 grams of glycine in each one—almost enough to satisfy those 3 grams used to improve sleep quality and reduce joint pain in studies.
Eating more collagen is a worthwhile, delicious undertaking, and after today’s post, you should have all the tools and reasons you need to start doing it.
Thanks for reading, folks. Take care!
Prefer listening to reading? Get an audio recording of this blog post, and subscribe to the Primal Blueprint Podcast on iTunes for instant access to all past, present and future episodes here .