Keeping it real: magnesium and tendonitis

There’s been a lot of talk lately around the internet about taking magnesium for tendon pain, specifically tendonitis. Let’s take a (scientific) look at the facts about magnesium and tendons, and see if we can come to any firm conclusions about this stuff.

First, let me say that a search of PubMed turned up nothing for the keywords “magnesium” and “tendonitis”. There was one hit for “magnesium” and “tendons”: a study done on dogs that showed a severe lack of magnesium can (and probably will) lead to problems with your tendons much like those caused by Levaquin and other quinolones. (If you’ve never taken Levaquin and/or don’t know what a quinolone is, don’t worry. They’re prescription drugs that have been implicated in causing some really horrific tendon destruction in certain patients. You can read a little more about it here, but for the purposes of this post just know that they’re very bad drugs for some people, and can cause tendon damage that in some cases is impossible to repair.) While I think that the study was good, it’s still just one study. And not one that shows that supplementing with magnesium will help to cure tendon pain, only that having an extreme deficiency in magnesium will probably cause tendon issues. These are not the same thing.

So, not much in the way of real research. But there’s quite a bit around the internet. Let’s start with one guy who calls himself an “expert” on tendonitis. His argument is this: Lots of people are magnesium-deficient in western society, mostly because of the crappy food that they eat (more on this in a moment). Further, while calcium is necessary to contract a muscle, magnesium is necessary to release that contraction. (This part is true.) So, according to him, if you exercise or perform repetitious movements like knitting on a regular basis, you’re using up both calcium and magnesium. Combine this with a supposedly magnesium-deficient diet, and you have a recipe for muscle tightness (all contraction, no release), which — again, according to him — is inextricably connected to tendon pain, because “If you have tendonitis pain, then you have muscles that are chronically too tight.”

Let me detour here for just a moment to address this last point. If, in fact, tightness really were a precursor to tendon pain, then you would expect athletes who are flexible and do lots of stretching not to suffer from tendonitis, tendonosis, or any other tendon condition. But the reality is different. Ballet dancers, for example, certainly some of the most flexible athletes around, have lots of tendon issues. In fact, according to the British Journal of Radiology, tendonitis accounts for 9% of all ballet injuries. Rock climbers get tendon conditions, gymnasts get them…the list really goes on and on. About the only group that doesn’t get tendon issues is the yoga folks, and it’s pretty obvious that this is because they don’t do a lot of repetitious/impact type exercise, not because of their flexibility.

Okay, anyway. Back to magnesium…

If you look at the Wikipedia entry for magnesium deficiency, it says a couple of interesting things. One, about 57% of the US population doesn’t meet the US RDA for magnesium. Aha! Deficient, right? well, not necessarily. The US RDA is just a number, and a very broad one at that. It is ONE NUMBER that tries to say how much of a certain vitamin or nutrient is “necessary” for everyone in the entire United States of America. That’s right, over 360 million people…all described by one single number.

Does anyone out there really believe that a 250-lb man needs the same amount of any nutrient, much less magnesium, as a woman who weighs half that? I hope not. Does it make sense that two people of the same size and gender need the same amount of a given nutrient if one of them is a triathlete and the other sits in an office all day? How about if one of them is pregnant and the other isn’t? If one is 20 years old and the other is 70…?

I hope you see my point. The US RDA is, for all intents and purposes, a useless number for any given individual. (Unfortunately, lots of bloggers pick up on that one number and use it to try to prove things.) But fortunately, Wikipedia gives you a much better way to judge whether you have a magnesium deficiency in your own body. It gives a long list of symptoms that typically are seen when someone really isn’t getting enough of the metal in their diet. To wit:

Symptoms of magnesium deficiency include: hyperexcitability, dizziness, muscle cramps, muscle weakness and fatigue. Severe magnesium deficiency can cause hypocalcemia, low serum potassium levels (hypokalemia), retention of sodium, low circulating levels of parathyroid hormone (PTH), neurological and muscular symptoms (tremor, muscle spasms, tetany), loss of appetite, nausea, vomiting, personality changes and death from heart failure. Magnesium plays an important role in carbohydrate metabolism and its deficiency may worsen insulin resistance, a condition that often precedes diabetes, or may be a consequence of insulin resistance. Deficiency can cause irregular heart beat.

(Notice that there’s nothing in there about tendonitis. Hmm…)

I’ve taken out the references, but if you check out the actual Wiki page they’re all listed. The above is supported by science, not just some blogger’s fantasy. So if you think that you have a magnesium deficiency, you might want to see if you have any of these symptoms. If you don’t, there’s probably no need to worry.

So here’s the wrap-up. As shown immediately above, most people (given that they don’t exhibit any of the Wiki-symptoms above) actually do NOT have a magnesium deficiency of any importance. If you take a multivitamin, you can be even more sure that you’re okay in this area, since most formulations include 50mg of magnesium in addition to whatever you’re getting from your diet. Further, there’s nothing in the scientific literature that shows going overboard and taking extra magnesium helps with tendon pain. Yes, if you’re chronically deficient, if you never eat any leafy greens, or drink coffee or tea, or use spices, or eat chocolate, or nuts, or frickin’ bread, then maybe you need some extra help, and a supplement might do you some good. But unless you’re getting muscle spasms and cramps along with your tendon pain, it’s a pretty safe bet that your magnesium levels are okay.

Magnesium food chart
Some values for common, high-magnesium foods

If you’ve had tendon pain for a while, do yourself a favor. Stop placing your hope in exotic remedies and take the free, one-minute tendon test located here. It will tell you, in plain English, what sort of tendon pain you have, and what you can do about it.