Magnesium, in its various supplemental forms, occupies a number of spots on Amazon.ca’s top selling vitamin and mineral supplement list.
It also happens to be one of the more under consumed minerals at population level.
These two characteristics make it a topic of extra intrigue, especially when I observe some of the evidence around supplemental magnesium for relevant conditions like migraine.
But I’ve also regularly observed anecdotal accounts of magnesium usage for relaxation purposes in the evening, but wasn’t aware about the state of the evidence in this area so I tasked my intern and colleague Evan of Kunutrition to take a closer look at magnesium’s potential role for both physical & mental relaxation.
I will let him take it from here.
Can Magnesium Help You Relax?
By Evan Huang Ku, RD, CDE, CBE
Magnesium is an essential mineral required for healthy bones and teeth, muscle functions, and metabolism of macronutrients.
But does its role in these capacities translate into a meaningful relaxing effect, as it is sometimes used for?
I took a look at the best available evidence to try to find out.
Can magnesium help you physically relax?
Magnesium is essential for the regulation of muscle contraction and relaxation. Magnesium deficiency can certainly cause muscle spasms or cramps, basically the extreme opposite of physical relaxation.
This begs the question, can magnesium supplement prevent muscle cramping?
Everyone has likely experienced cramping in the past. However, cramping is more often associated with older age, pregnancy, or exercise.
According to a Cochrane review published in 2020, magnesium supplementation did not reduce the frequency, duration, and intensity of idiopathic muscle cramps, or cramps without apparent causes, in older adults.
In pregnant women, the results are also inconclusive.
And unfortunately, no randomized controlled trials evaluated magnesium’s effectiveness against exercise-induced cramping.
Now, you may be rightfully thinking, being a little tense doesn’t mean you are experiencing something extreme like muscle spasms or cramping.
Unfortunately, there is just no research on whether magnesium will help if your body is feeling a bit tense.
Here’s what we do know. Magnesium supplements reduced exercise-induced muscle soreness, according to a small double-blinded trial. Only two of the twenty-two participants met the Recommended Daily Allowance (RDA) for magnesium intake, indicating some potential inadequacy in intake.
So, if you aren’t consuming enough magnesium, taking supplements may improve muscle soreness from physical activity.
But, keep in mind this is a very small-scale study, and more research is needed for me to make a confident recommendation.
Can magnesium help you mentally relax?
Anxiety & Stress
Relaxation is more than physical relief, what about mental relaxation?
Several studies have found associations between magnesium status with anxiety and stress.
However, the real question is, can magnesium supplementation reduce anxiety or stress, causing one to relax?
The most recent systematic review to date examining this relationship was published in 2017. This review included studies on people with mild to moderate subjective anxiety and people vulnerable to anxiety, including those with premenstrual syndrome, mild hypertension, and postpartum mothers.
Some studies, not all, found a modest effect in improving mild anxiety. However, all these studies administered magnesium with other ingredients, like vitamin B or Hawthorn. Therefore, it’s impossible to say the improvement is attributed to magnesium alone.
For premenstrual syndrome, magnesium has a potentially positive effect on anxiety. However, these studies have design issues lacking appropriate placebo controls, making it difficult to form a definitive conclusion. Moreover, only one randomized control trial met the inclusion criteria for postpartum mothers and found no improvement in subjective anxiety using magnesium.
Lastly, magnesium reduced blood pressure but not subjective anxiety levels in hypertensive people.
The authors of this systematic review find magnesium to have a “suggestive but inconclusive” beneficial effect for people with mild anxiety or premenstrual symptoms, suggestive and inconclusive because of the poor-quality study designs.
In terms of stress, none of the studies included in this systematic review used a validated measure for stress. This means there was not enough evidence to say magnesium can reduce stress.
Since the publication of this systematic review, a randomized clinical trial that used a validated stress assessment tool was published. It included study participants with suboptimal serum magnesium levels and moderate to severe stress.
In eight weeks, supplementing with 300mg improved stress by 40%, suggesting magnesium to be quite helpful with stress, especially if you have inadequate magnesium intake.
For those under severe stress, a combination of magnesium and vitamin B6 are even more effective.
However, this study was not a double-blinded clinical trial, introducing some bias risk. Also, it did not include a placebo group to evaluate the actual effectiveness of magnesium supplementation.
Magnesium has a role in regulating the central nervous system excitability. Naturally, scientists were curious if supplementation could improve sleep. One double-blinded clinical trial found 500mg of magnesium supplementation for eight weeks improved sleep time and efficacy in adults aged 65 years with moderate to severe insomnia.
A very recent meta-analysis that pooled the data from this study and two more randomized control trials found magnesium supplements to be able to reduce sleep onset latency time by 17 minutes. In other words, study subjects were falling asleep sooner.
However, all three clinical trials were critiqued to be at high risk of bias, and a recommendation to use magnesium for insomnia could not be made by the meta-analysis.
Magnesium supplements cannot help you prevent muscle cramping but may help you alleviate some soreness from exercising if you have inadequate intake.
In terms of helping your mind relax, magnesium may have a beneficial effect if you have mild anxiety or premenstrual syndrome-related anxiety. However, the evidence is still inconclusive. Regarding stress, there is some potential that magnesium can make a difference.
If you are trying to improve your sleep quality, it definitely doesn’t hurt to give magnesium a try.
All things considered, it’s not a bad idea to pay attention to your magnesium intake, whether through diet or supplements, given that more than 45% of Canadians have inadequate dietary intake.
The recommended daily intake is 420mg for adult male and 320mg for adult females. Requirements for pregnancy may be higher. If you want to eat more magnesium food, try pumpkin seeds, spinach, soy milk, or edamame.
This blog post is written by Evan Huang-Ku, a dietitian helping to incorporate your favorite cultural food into a healthy diet.