Most health and fitness writers don’t spend a lot of time on cartilage. As tissues go, it’s fairly isolated. It doesn’t contain blood vessels, so we can’t deliver blood-borne nutrients to heal and grow it. Cartilage has no nerve cells, so we can’t “feel” what’s going on. Doctors usually consider it to be functionally inert, a sort of passive lubricant for our joints. If it breaks down, you’re out of luck, they say.
But that’s what people used to think about bone, body fat, and other “structural” tissues: that they are inert rather than metabolically active. The truth is that bone is incredibly plastic, responding to activity and nutrition, and that body fat is an endocrine organ in its own right, secreting hormones and shaping the way our metabolism works. What about cartilage? Can we do anything to improve its strength and function?
Cartilage is made of water, collagen, and proteoglycans, a protein-polysaccharide bond that provides elasticity. Right there we see one avenue for altering cartilage health—hydration.
Go down to the pet store and look at the dehydrated tendons. They’re dry, stiff, and completely unmanageable. Go down to the Asian market and check out the fresh beef tendons. They’re slippery, pliable, and still tough as nails. Now consider that cartilage and tendon are made of very similar stuff. Without hydration, cartilage doesn’t slide as easily. It can’t do its job.
And once you have cartilage damage, hydration is even more important because damaged cartilage is harder to hydrate. In one study, researchers dehydrated and then rehydrated damaged pig cartilage and intact pig cartilage, finding that the damaged cartilage absorbed far less water than the intact cartilage.
Eat extra collagen/gelatin.
Our need for and collective failure to obtain adequate dietary glycine underpins the growing bone broth/supplemental collagen industry. The reason why drinking broth and eating collagen makes so many people feel better is that we are providing a fundamental nutrient: glycine. See, our bodies need about 10 grams of glycine each day to maintain basic metabolic functions. We only make 3 grams, so 7 grams must come from the diet. A major function of glycine is to maintain and repair cartilage. If you’re training hard or trying to recover from existing damage, your glycine needs skyrocket.
Conclusive studies showing collagen rebuilding or buttressing cartilage are lacking, but we have hints. One study found that supplementary collagen improves joint pain in athletes who complain about their knees. And more recently, a study found that giving dietary collagen alongside Tylenol to patients with osteoarthritis improved joint pain and function over Tylenol alone.
Motion is lotion. You need to walk. You should develop a daily movement practice, even if it’s just bodyweight squats while brushing your teeth and waiting for the train, your favorite VitaMoves routines while watching TV, or a good old fashioned rajio taiso.
Be sure to include mobility work, too, like the aforementioned VitaMoves, KStarr’s MobilityWOD, or MDA writings on joint mobility, foam rolling, and stretching. Many joint injuries occur because the tissues surrounding them—your muscles, your fascia, your major movers—are restricted, placing undo stress on the joint itself.
Walk over varied terrain.
Walking through civilization isn’t the same as ambling across a wild landscape strewn with stones and dips and fallen branches and slippery leaves, inclines and declines and slants. The former is linear and predictable. You just walk without having to think or react. It’s rote.
Walking across varied terrain exposes your cartilage to different positions and different loading patterns.
It starts with the foot’s connection to the ground. If you’ve got a big thick slab of rubber blocking the millions of nerves in your feet from sensing the ground, everything up the kinetic chain suffers.
Do so gradually, though. Going barefoot after a lifetime in protective shoes can be a shock. You don’t want to get injured; being sedentary is terrible for cartilage (and everything else).
Travel back in time and quit the soccer team.
If you have kids, don’t force them to specialize. Playing a variety of sports and activities early on and waiting to specialize until later adolescence is better for future athleticism and safer for the joints. Let them be kids. Let them play and cavort and explore multiple sports. Or no sports, just movement, if that’s what they want.
“Chronic repetitive loading” of the joints associated with intense sport practice reliably produces cartilage damage in adults, too. We can’t travel back in time, but we can eliminate any chronic repetitive loading our joints are still subject to.
Osteoblasts are to bone as chondrocytes are to cartilage. Just like an osteoblast responds to load by increasing bone mineral density, chondrocytes respond to load by increasing cartilage growth and repair. You have to load it or lose it. Studies in cows find that cartilage is most robust in joints that actually receive loading.
Endogenous growth factors like human growth hormone play major roles in cartilage repair. And absent pharmacological assistance, we get the largest bolus of growth hormone at night, during sleep. Whether we’re recovering from the microdamage caused by smart training and regular loading or the degenerative damage caused by poor mechanics and outright injuries, sleep is where most of the repair happens.
Read my post from a couple years back on slacklining. I still have the same one set up in my backyard, and I still take frequent breaks to hop on and balance and walk.
Slacklining forces your body to make micro corrections constantly. That’s why a first timer putting foot to slack line will wobble uncontrollably and feel like they don’t know their own body: they’re placing enormous demands on a neuromuscular system that’s never encountered so unstable and dynamic an environment. It takes a while to get their bearings. And all the while, the knees, hips, and ankles are facing very unique loading patterns.
Plus—and this isn’t “scientific” or cited, just personal instinct—anything that puts a smile on your face while it forces a training adaptation will be more effective than one that makes you grimace. Teach your cartilage that work is fun.
Lose excess weight.
There can be too much load. We want the application of loading to be acute and intermittent. We want to control it. So, workouts, hikes, jumping, squatting, climbing, running and other short term activities generally improve cartilage health, particularly when using proper technique and allowing for ample recovery. But carrying 20-30 extra pounds is chronic loading because it never goes away. You can’t take that pack off.
Research shows that weight loss can really improve cartilage health. In one study, obese people with arthritis who lost a large amount of weight (5-10% of their bodyweight) greatly reduced cartilage degeneration. For many of them, it stopped entirely. If weight loss has that big of an effect on existing cartilage damage, imagine how it would affect healthy cartilage.
Those are 13 practices I find most useful in buttressing cartilage against damage and degeneration.
Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.