What’s the truth about magnesium and sleep?
You may have read in the past that taking a magnesium supplement can help aid a more restful night in the land of nod, but is there any truth in this?
We know that magnesium contributes to the reduction of tiredness and fatigue, and is required for normal psychological function and the normal functioning of the nervous system.* But does it do this by increasing the amount or quality of our sleep? The answer to this may be complex.
You may know that any kind of inflammation is not a good thing, especially when it continues chronically. It involves swollen tissue and the release of inflammatory markers leading to a state called ‘inflammatory stress’. For example, someone who has an inflamed skin condition, or gum disease. One factor that may increase inflammatory stress is disrupted sleep/sleep deprivation. Inadequate sleep duration has been associated with increases in several inflammatory biomarkers including plasma C-reactive protein (CRP). Sleep quality also has been associated with increased morning concentrations of inflammatory biomarkers IL-6 in healthy adults, elderly women and spousal Alzheimer’s caregivers. Higher circulating levels of IL-1β have been seen in women, but not men. Magnesium intake has been found to be inversely related to elevated circulating CRP concentrations, a marker of acute stress to the body. Thus, subclinical magnesium deficiency through exacerbating a low grade inflammation could be a factor in sleep disruption or deprivation. The possibility that magnesium deprivation affects sleep quality is supported by a few human and animal studies:
A study found 27 patients with unusual behaviours of the nervous system during sleep (parasomnias) displayed low blood magnesium, and also had nocturnal EEG abnormalities occurring during slow wave sleep.
In a placebo-controlled, randomised cross-over experiment with 12 older patients (aged 60 to 80 years), magnesium supplementation significantly reversed brainwave electroencephalogram (EEG) changes, including decreased slow wave sleep, that occur during aging.
Magnesium treatment of alcohol-dependent patients (who often have magnesium metabolism disturbances), significantly decreased sleep onset latency and improved subjective sleep quality as assessed by the Pittsburg Sleep Quality Index (PSQI).
In rats, magnesium deficiency significantly increased wakefulness at the expense of slow wave sleep; magnesium supplementation restored sleep organization to its original pattern.
In addition to a chronic inflammatory stress relationship, sleep architecture and magnesium may have a biochemical relationship. It has been suggested than magnesium regulates sleep because it is an N-methyl-D-aspartate antagonist and a γ-aminobutyric acid (GABA) agonist. Sleep architecture, especially slow wave sleep, apparently is closely associated with the glutamatergic and GABAergic system.
So how do I improve my own sleep?
If you have a poor diet, high intake of alcohol, or any reason to believe you’re not absorbing food properly, and you have poor sleep, it may be worth a trial of a magnesium supplement. You may want to get your blood levels measured first. The nutrient reference value is 375mg per day for magnesium so you, unless you have a proven deficiency you wouldn’t want to go too much higher than this, or for too long.
* EU REGISTERS ON NUTRITION AND HEALTH CLAIMS