I’ve found that websites will publish “this or that supplement does or doesn’t work for testosterone” based on the evidence of one or two studies; the truth of all science is that many studies are needed before anyone in the clinical community feels comfortable with even a “perhaps,” one way or the other.
Case in point, the essential mineral Magnesium. No matter how someone feels about their testosterone, most Americans are falling 33% short of their recommended Magnesium intake. This has devastating impacts on protein synthesis and muscle performance. Not only that, the science does indeed support the correlation between Magnesium levels and higher testosterone. Let’s get to the data.
✲ Magnesium has been seen in multiple studies to correlate to higher testosterone in athletes.
✲ Following studies of athletes, one important study gave Magnesium to “sedentary” individuals–and saw their testosterone go up, too.
✲ Magnesium intake, already low, decreases sharply as men age.
✲ A groundbreaking study of older men found substantial hormone increases when they started taking Magnesium supplements.
It Usually Starts with Athletes
I sometimes hear people question a study of supplements or nutrition because the research is only conducted on bicyclists, runners, or some other athlete-type. But we all need to give these scientists a break: it’s a lot easier to recruit people for sports-medicine research when they’re already active, versus asking a group of men who aren’t exercising at all to jump on a treadmill with electrodes on their chests.
It makes sense, then, that the first real credible study of Magnesium’s effect on testosterone was done with elite college football players. They’re young, they’re right there on University campus where the research takes place, and they already have good baselines to study.
Well, the study found their testosterone went up–significantly. Total testosterone, free testosterone, insulin-growth-factor (IGF) hormone went up, and even their strength increased significantly over the control group. This was one of the first human trials that showed a direct link between magnesium intake and testosterone.
What About Non-Athletes?
Glad I asked for you. Several years after the college athlete study, another study was conducted with three groups of males:
- A sedentary group that the researchers gave Magnesium.
- An exercise group that also took Magnesium.
- And an exercise group that took no Magnesium.
At the end of the 4 week study, the second group had far and away the largest increases in free and total testosterone. It should be noted, though, that the sedentary group did see a statistically significant increase in their resting testosterone and their “exhaustion” testosterone (levels taken after an exercise period). That means that even with zero fitness training in the intervening 4 weeks, sedentary men saw a substantial boost to their exercise capabilities.
Most Important Study
For the sake of my readers’ time, I did not include the literally dozens of other studies and literature reviews corroborating these data. There are more studies on animals–from mice to camels, of all things–but there were no real data showing a failure of Magnesium, or lowering of testosterone.
What I will end on, however, is a study that had the farthest reach, and the most impact for everyday men. In the study, 399 men above the age of 65 were selected for blood sampling; several other tests were taken, including a strength test.
In the data, scientists were able to establish a clear connection between higher levels of Magnesium in the blood and higher testosterone. These data also correlated to higher grip strength and lower risk of Parkinson’s disease.
This correlation was “independent” of other variables. Verifying the independence of a variable requires a large sample size, such as this one, and is an incredibly useful tool for researchers establishing a link between Cause A and Effect B.
In brief, to verify independence, researchers isolate the sample population by a third factor, like body weight. Then they test for the Magnesium/testosterone relationship. They then must go through that process with every other factor–height, age, race, anything distinguishing. If all the third-tier sample populations show the same correlation, then it is the Magnesium, and nothing else, causing the effect of higher testosterone.
As I mentioned earlier, data from the Journal of Nutrition indicates that as men age, they take in less Magnesium–the same time period when their testosterone begins to drop. Supplementing with Magnesium appears to be an effective remedy.
In my research on this important mineral, I came across a warning about Magnesium toxicity–according to the Harvard Medical School, the safest upper limit of supplementation is 350 mg/day, depending on body weight. You can ingest more if the rest comes from food, but no more than that by vitamin/pill. However, the study of college athletes took 450 mg/day, and the study of sedentary and exercising men took 10 mg per kg of body weight (a whopping 770 mg for a 170 lb. man).
Also, any readers interested in some science for fun can read an article here briefly detailing how Magnesium plays a role in the “unzipping” of protein RNA; it is the same mechanism by which it increases testosterone in men, but helping the partner proteins of the hormone (literally) express themselves.