After I finished writing my glucosamine and chondroitin supplement guide and follow-up executive overview, I realized that what I had written could be disheartening. I don’t want to be solely the bearer of bad news, and I’ve also experienced firsthand how presenting only the negatives can fail to inspire change. Since one of the foremost goals of Climbing Nutrition is to improve your nutrition (and thereby your climbing), this isn’t ideal—and so I want to provide some tips on how you can hopefully improve the health and tenacity of your connective tissue.
To be certain, I also don’t want to provide false hope; if a diet or supplement does not or cannot work, I’m not going to hedge about it. The world of nutrition is filled with implausible and unproven advice, and it will remain a secondary goal of this website to actively fight against pseudoscientific nutrition, especially as it relates to climbers. But in many cases, if there is a worthless recommendation to debunk, there is also something of worth to recommend.
The unfortunate truth is that these recommendations are rarely, if ever, as strong or sexy as their pseudoscientific counterparts (hence the “might” in the post title). That’s the reality of science-based nutrition, though—there are no guarantees, and many areas that are potentially promising have a dearth of evidence, making it hard to know whether they’ll actually pan out. Regardless, these same recommendations are often healthy or helpful in at least some known factor, unlike many pseudoscientific recommendations that have virtually no worth when removed from their false promises.
Enough preamble, though! Here are four frequent tendon-related recommendations that have no scientific merit that should be skipped, and four changes I can recommend in their place.
Don’t Do: Supplement with Vitamin C
Vitamin C is commonly recommended for connective tissue health and healing because it’s a necessary ingredient in the formation of collagen—but if you don’t have enough vitamin C to effectively maintain your collagen, a strained pulley is the least of your worries because you’ll be bleeding from the gums and losing teeth as well.
Why would this happen? Well, let’s first examine how vitamin C actually influences the formation and final structure of collagen.
The complete protein “collagen” is a complex cord formed of numerous fibrils of tropocollagen that are themselves formed of three twisted polypeptide strands. On a molecular level, these twists in a chain of amino acids don’t “just happen”—they require special amino acids. In the case of collagen, the tight twists rely on the amino acid hydroxyproline, and the formation of hydroxyproline requires vitamin C.
Without sufficient vitamin C, the body cannot effectively form hydroxyproline, and without sufficient ability to form hydroxyproline the structure of collagen is compromised as the hydroxyproline is replaced with other amino acids that are less capable of twisting. This reduces the strength of the final collagen in the same way the strength of a rope would be compromised if none of the individual strands were twisted or braided together. And just like a weak rope, the weakened collagen breaks easily.
When our diet is severely vitamin C-deficient, we produce only weak collagen, resulting in the disease scurvy. Because our collagen is weak, wounds heal poorly (because our skin contains collagen), bruises occur regularly (because our blood vessels contain collagen), the gums begin to bleed and you might even lose teeth (because collagen helps hold our teeth in place). Thankfully, scurvy is rare today in the developed world because vitamin C is present in sufficient amounts.
The RDA for vitamin C is 90 milligrams for adult men and 75 milligrams for adult women, and you will easily get this much from your daily diet provided you have a single serving of fruits or vegetables; if you’re meeting the actual recommendation of 5-9 combined servings daily, there’s a very good chance you’re getting somewhere in the range of 200-400% the RDA for vitamin C. To protect your tendons, though, you don’t even need this much because scurvy can be prevented by consuming only roughly 10 milligrams of vitamin a day!
This isn’t to say you shouldn’t strive to get the full RDA of vitamin C daily (or at least as a weekly average)—you should for other health-related reasons—but rather that healthy collagen formation is one of the first functions of vitamin C, and that your body isn’t going to compromise on the integrity of your connective tissue unless it absolutely has to. Assuming you get at least minimal amounts of vitamin C a day, you are all but guaranteed to have sufficient vitamin C for the formation of hydroxyproline, and thus have nothing to worry about.
Do Instead: Eat More Phytonutrient-Rich Foods
Instead of worrying about a lone nutrient like vitamin C, you’d be better off simply increasing the amount of fruits and vegetables in your diet. Fruits and vegetables contain numerous phytonutrients, which are non-essential, non-vitamin, non-mineral nutrients that may augment our health in subtle ways. Some of these phytonutrients, such as the flavonoids proanthocyanidin (found in numerous fruits, but particularly berries) and quercetin (found in numerous vegetables, but particularly alliums), could have a special affinity for both connective tissue and muscle tissue.
Phytonutrients aren’t magic bullets against injury. At best we have limited in vivo, human data that suggests they may help—such as by increasing the speed at which musculoskeletal function returns to normal (outside of other antioxidant activity). This isn’t enough for me to tell you that any phytonutrient is guaranteed to to improve your connective tissue, but it is a start.
The thing is, though, even if future research shows that flavonoids and other phytonutrients do little to nothing for the tendons and ligaments, the foods you have to eat to get those phytonutrients are still great to have in your diet for other reasons. Unlike a recommendation for vitamin C—which is more likely to result in the purchase of some Emergen-C or vitamin C capsules than a bag of oranges—a recommendation to eat more phytonutrients can only be accomplished by making dietary changes. This means eating more fruits and more vegetables, and that’s an intervention I can rally behind regardless of whether they’ll have a direct, phytonutrient-related effect on your connective tissue.
Don’t Do: Supplement with Manganese
Manganese is a trace essential mineral that acts as a cofactor for prolidase, an enzyme important to collagen formation and breakdown. Inadequate dietary manganese would hypothetically cause issues with collagen metabolism, leading to symptoms akin to those of the genetic disease prolidase deficiency, such as skin lesions, ulcers, and rashes. I say “hypothetically” because we’ve never once witnessed an inadequate intake of dietary manganese in the wild!
In a controlled lab setting, we’ve experimentally induced manganese deficiencies by providing humans with ultra-low manganese diets—and sure enough, these diets result in scaly skin and rashes (among other issues). But in the real world, where manganese is an abundant mineral that is only needed by the human body in trace amounts, deficiencies just don’t happen!
Furthermore, even if you wanted to increase your daily manganese intake, you really wouldn’t be able to because the absorption of manganese probably relies on an easily saturatable transporter, which is basically like a single lane road—easily clogged. If that road can only handle 1,000 cars per hour then it doesn’t matter if 500,000 cars are lined up because only 1,000 are going to get through. Ergo, only a small amount of manganese can be absorbed per meal.
In fact, when all sources of dietary manganese are accounted for across a day, less than 5% of the manganese present is absorbed. This is common among the trace and ultratrace minerals because biologically there is no reason for why we should absorb a lot—we don’t need the excess trace minerals, they increase the risk of food-related nutrient toxicity, and they would increase the burden on the kidneys to excrete what we cannot use.
I’m not a fan of supplementing with any vitamin or mineral because research doesn’t support it outside of an acute deficiency, but in the case of manganese I’m doubly against it. Even if you take a 50 milligram supplement (over 2000% the AI), you’re unlikely to absorb more than around 0.015 milligrams—about the same amount you would absorb from any dietary source. That’s a pretty poor return on your investment.
Do Instead: Consume Sufficient Calories (and Carbohydrates)
You can’t increase collagen production in your tendons and ligaments above normal, healthy levels—it’s a basic tenet of science-based biology that “healthy” is optimum, and there’s no further level to be achieved—but there are ways you can decrease or impair your collagen production. One potential way is by increasing your resting cortisol levels, which can happen dietarily by consuming inadequate calories or carbohydrates.
It’s repeatedly been found that not consuming sufficient calories increases resting cortisol levels (two studies linked here for reference). Generally, these studies use a greater degree of caloric restriction in order to produce weight loss, which is a greater degree of restriction than most climbers adhere to. Cortisol doesn’t suddenly spike when calories drop below a certain threshold, however, but increases gradually as it slowly becomes more necessary.
Beyond the effects of caloric restriction, the restriction of carbohydrates is likely to produce even further increases in cortisol. Cortisol helps prevent our blood glucose from dipping (and thereby harming our brain) by increasing insulin resistance and catabolizing skeletal muscle in order to free up amino acids for gluconeogenesis (literally, “new glucose creation”). Thus, for obvious reasons cortisol becomes more and more necessary as dietary carbohydrates become scarcer because because our body is forced to produce more and more of its own glucose.
(This is also why cortisol spikes during exercise, particularly long-lasting endurance exercise—after we exhaust our muscle glycogen, the muscles start taking glucose from the blood. Eventually the body is forced to respond by cutting off the muscles’ glucose supply through cortisol release, thereby preserving the remaining glucose for the brain and increasing the creation of new glucose.)
In the past, cortisol (hydrocortisone) and cortisone shots were a standard treatment for tendon injuries, but they’ve fallen out of favor in light of significant evidence that tendon healing and strength are actually impaired by the hormone. In general, cortisol is also an anti-anabolic hormone, meaning it downregulates the production of new proteins. This suggests that tendon production and repair could be compromised when cortisol levels are unnaturally high for significant periods of time (though local levels in the tendons will never be as high as during a shot).
Now, I don’t want to oversell the calorie/carbohydrate/cortisol/connective tissue connection; I just want to highligh a potential area for improvement, an area that I frequently see climbers lack in. Cortisol can spike due to numerous other causes (lack of sleep, general life stress, excess exercise without rest), and there are also numerous, more important factors in all tendon and ligament injuries. It’s still a potential risk factor, however, and when combined with the other general downsides of not consuming sufficient calories for your level of activity (such as increased muscle fatigue, weakness, and recovery time)—all of which can also predispose one to injury—it might be something to think about. And since a higher-carbohydrate diet is likely to provide performance benefits as well, there’s no real downside.
Don’t Do: Take Vitamin or Mineral Supplements (Including Multivitamins)
Occasionally, other vitamins and minerals are also noted for their connective tissue health properties. Instead of going through them one at a time as I did with the pro-collagen favorites vitamin C and manganese, I’m going to approach and debunk them en masse.
The #1 problem with recommending any vitamins and minerals to improve connective tissue health or healing is that deficiencies are relatively uncommon (just as we saw with vitamin C and manganese). And when we then move away from the nutrients that play direct roles in the biology of your connective tissue and towards the ones that play at best minor and indirect roles, it just becomes less and less likely that supplementation can change or influence anything pertinent. It’s beyond grasping at straws; it’s essentially saying “vitamins and minerals are important to your tendons because you need vitamins and minerals to live.”
Contrary to what is commonly believed, vitamins and minerals are not capable of improving health beyond normal levels of intake, which are reflected through scientifically established RDAs and AIs. Just like you can’t improve the health of your car by doubling the amount of oil or coolant, you can’t improve your health by doubling your vitamin or mineral intake. Each vitamin and mineral has a role to play in our health, and once we have sufficient amounts of a nutrient to perform those tasks there is no benefit to consuming more.
If you suspect you have a vitamin or mineral deficiency, go to a doctor and get tested. Such deficiencies are rare today, however, with our abundant and diverse diets—not to mention food fortification and enrichment—so the chances of being diagnosed with one are slim.
Do Instead: Eat a Diverse, Healthy Diet
There isn’t a single vitamin or mineral supplement that works to do anything aside from replete nutrient levels in an acute deficiency. Whenever we see positive results in the scientific literature for a particular vitamin or mineral, it’s inevitably in a population that has dietary deficiencies or insufficiencies in regards to the nutrient in question.
On the other hand, there is a plethora of research out there to support eating a healthy diet that contains a diversity of whole foods. From the standpoint of general health, we know that eating more fruits and vegetables, legumes, whole grains, mushrooms, roots, and fish is beneficial. We might not have specific data on these diets in terms of tendon and ligament health, but we can say for certain that eating more of the above foods will be far more likely to increase your connective tissue health than taking a supplement that has virtually no supporting evidence (and certainly none in regards to the connective tissue).
So ditch the multivitamin and individual vitamin/mineral supplements and use the money to buy more healthy, whole foods instead. You’ll enjoy them more, and they’ll do a lot more for your health in general.
Don’t Do: Consume Collagen-Based Proteins
There’s a term for the type of belief that underlies collagen-based proteins: sympathetic magic. Sympathetic magic is, simply put, the belief that like influences like. A common example is the belief that certain foods are aphrodisiacs because they superficially resemble the genitalia—but in this case, it’s the idea that consuming something made of collagen will be good for your own collagen.
Unfortunately, there’s no evidence that consuming a collagen-based protein is really good for anything because collagen-based proteins are merely poor-quality proteins. Poor-quality proteins only contain a limited amount of essential amino acids, and while they may be rich in the particular amino acids found in collagen there is no evidence that they will actually increase collagen production.
Beyond the false concept of sympathetic magic, there’s really no reason to believe that eating collagen would increase collagen production anymore than there’s a reason to believe eating liver would be helpful for cirrhosis or eating eyeballs would improve your sight. Proteins are made of amino acids, and the source of those amino acids is mostly irrelevant; as long as you get all the amino acids you need in the amounts your body needs them, then your collagen production will be ideal.
Do Instead: Eat More High-Quality Proteins
Collagen-based proteins are just poor quality proteins. When you eat a high-quality protein, you get everything you’d get from a collagen-based protein and then some.
A high-quality protein is also more likely to stimulate collagen production in the connective tissue in the first place. Much less work has been done on tendon protein synthesis than on muscle protein synthesis, but some research suggests they are connected, which carries the implication that the same things that are good for muscle protein synthesis (notably leucine-rich proteins) would be good for tendon collagen synthesis as well.
This muscle/connective tissue relationship has been further demonstrated by a rat study in which a leucine-rich diet increased the hydroxyproline content of tendon collagen (remember how hydroxyporoline is necessary for tendon strength?). Rat studies do not always translate well to humans, but in the case of generic muscle and tendon protein synthesis it’s likely there is significant crossover since it’s a pathway common to all mammals.
To be sure, there’s nothing wrong with eating collagen-based foods. You can enjoy broths and gelatins in a healthy diet without believing they’ll simultaneously improve your tendons and ligaments (or skin, or hair, or whatever else they’re advertised to improve). But going out of your way to eat foods you don’t enjoy just because they’re rich in collagen—I’m thinking about the steamed fish skins my friend’s Taiwanese girlfriend insisted were good for my skin—isn’t worth your while. You should definitely avoid collagen-based protein powders like so-called “beef protein”, because these are the height of worthlessness.
In short, stick with high-quality proteins and leave the poor-quality, collagen-based ones alone for the foods you enjoy.
There are many recommendations for tendon and ligament health that are useless. They’re unsupported by science, and often lack even basic scientific plausibility. Sympathetic magic is a fun concept for science fiction, but less so for science reality.
There are also many things you can do that may positively influence your tendons and ligaments tissue. What’s even better is that these same recommendations are broadly supported by science-based nutrition research to be healthy, even if they don’t wind up being specifically beneficial to your connective tissue. This is the type of recommendation I favor—the type that has no downside and many upsides.
I cannot promise that you’ll render yourself impervious to elbow tendonosis, strained pulleys, or rotator cuff tears if you follow my recommendations—science-based nutrition never makes these sorts of promises. What I can promise is that you’ll be doing more for your health (and by extension, your connective tissue) by eating more, healthier foods than by singling out “pro-collagen nutrients”.
So here’s to your tendons and ligaments! Eat right, and eat enough, and they’ll take you far.
The following common recommendations have no scientific evidence:
- Vitamin C: The majority of individuals in developed countries consume enough vitamin C, and virtually all of them consume enough vitamin C to encourage normal collagen formation. When we lack sufficient vitamin C for normal collagen formation, we develop scurvy.
- Manganese: Manganese is one of the most uncommon mineral deficiencies, and has never been encountered in humans outside of the laboratory. Supplements are probably worthless because it’s unlikely we can absorb more than a tiny fraction in a single serving.
- Vitamin and Mineral Supplements in General: Vitamins and minerals are required by the human body for normal function, but once you consume enough to meet the levels needed for normal function (reflected by RDAs and AIs) then there is no evidence they can improve health further. Most vitamins and minerals play only minor or indirect roles in collagen formation, and even in the case of an acute deficiency most would not significantly affect your tendon or ligaments.
- Collagen-Based Proteins: Collagen-based proteins are low-quality proteins that lack most essential amino acids. There is no evidence they increase collagen formation (there is actually evidence they don’t), and they’re a waste of time and money unless they happen to be in a food you enjoy like broth or gelatin.
The following recommendations are scientifically evidenced to improve your health in general and have plausibility for improving tendon and ligament health:
- Phytonutrients: Some phytonutrients like proanthocyanidins and quercetin (found in berries and alliums, respectively, as well as other fruits and vegetables) have preliminary research suggesting they may influence tendon and ligament cells.
- Calories and Carbohydrates: Diets that are low in calories and carbohydrates can cause resting cortisol levels to increase. Cortisol can inhibit the formation of new tendon collagen and potentially increase breakdown. Increasing calories to sufficient levels to support your activity level and consuming enough carbohydrates to maintain normal blood glucose levels throughout the day can decrease resting cortisol levels.
- Eating a Healthy and Diverse Diet: A healthy and diverse diet containing fruits and vegetables, legumes, whole grains, mushrooms, roots, and fish is much more likely to improve your health and by connection connective tissue health than vitamin or mineral supplements.
- High-Quality Proteins: High-quality proteins contain the essential amino acids necessary to encourage normal protein formation. There is also evidence that muscle protein synthesis (which requires leucine-rich high-quality proteins) and tendon protein synthesis are linked, suggesting that high-quality proteins should encourage better collagen formation.