The cheapest magnesium supplements contain magnesium oxide, which the body does not absorb well. They cost next to nothing at a drugstore, yet they can improve the quality of your sleep – and they don’t cause side effects. Researchers at Shahid Beheshti University of Medical Sciences in Teheran, Iran discovered this when they did an experiment on insomniac over-60s.
Sleep is an important factor in our health, but the older you get the more the quality of sleep declines. This might be, the Iranians write in the Journal of Research in Medical Sciences, because the amount of magnesium available to the body decreases with age. This is a result of osteoporosis – bones are the main store of magnesium in the human body – but also because the body’s uptake of magnesium declines.
If this theory holds water, then over-60s with a sleep problem could benefit from magnesium supplementation. So the Iranian researchers gave two dozen subjects, average age 65, who complained of sleeplessness, two pills containing 250 mg magnesium in the form of magnesium oxide twice a day for eight weeks. An equal-sized control group took a placebo.
The subjects’ diet provided less than the amount of magnesium recommended by nutritionists. This is normal in countries where modern food industry determines food consumption. Foods containing magnesium include wholegrain products, nuts, fruit, dark chocolate, leafy green vegetables such as spinach, soya, dairy products and meat, and foods that have not been highly processed.
Supplementation resulted in the subjects lying awake for less time [their sleep time was half an hour longer], and they also fell asleep a little faster [their sleep onset latency was 12 minutes shorter].
Magnesium supplementation improved the subjects’ Sleep efficiency. In addition, the subjects that had been given magnesium complained less of sleeplessness after eight weeks. Their Insomnia severity index was lower.
So while magnesium supplements didn’t solve the subjects’ sleeplessness, they did help reduce the problem.
If the researchers had given their subjects magnesium for a longer period of time, or used higher doses, or given them a more easily absorbable form of magnesium, they might have obtained better results. The table below suggests this. It shows that the magnesium level rose by a meagre 4 percent in the subjects that had received magnesium.
So what would have been the effect on sleep quality if the magnesium level had risen not by 4, but by 8 percent? Or by 12 percent?
The effect of magnesium supplementation on primary insomnia in elderly: A double-blind placebo-controlled clinical trial.
Nearly 50% of older adults have insomnia, with difficulty in getting to sleep, early awakening, or feeling unrefreshed on waking. With aging, several changes occur that can place one at risk for insomnia, including age-related changes in various circadian rhythms, environmental and lifestyle changes, and decreased nutrients intake, absorption, retention, and utilization. The natural N-methyl-D-aspartic acid (NMDA) antagonist and GABA agonist, Mg(2+), seems to play a key role in the regulation of sleep. The objective of this study was to determine the efficacy of magnesium supplementation to improve insomnia in elderly.
MATERIALS AND METHODS:
A double-blind randomized clinical trial was conducted in 46 elderly subjects, randomly allocated into the magnesium or the placebo group and received 500 mg magnesium or placebo daily for 8 weeks. Questionnaires of insomnia severity index (ISI), physical activity, and sleep log were completed at baseline and after the intervention period. Anthropometric confounding factors, daily intake of magnesium, calcium, potassium, caffeine, calories form carbohydrates, and total calorie intake, were obtained using 24-h recall for 3 days. Blood samples were taken at baseline and after the intervention period for analysis of serum magnesium, renin, melatonin, and cortisol. Statistical analyses were performed using SPSS19 and P values < 0.05 were considered as statistically significant.
No significant differences were observed in assessed variables between the two groups at the baseline. As compared to the placebo group, in the experimental group, dietary magnesium supplementation brought about statistically significant increases in sleep time (P = 0.002), sleep efficiency (P = 0.03), concentration of serum renin (P < 0.001), and melatonin (P = 0.007), and also resulted in significant decrease of ISI score (P = 0.006), sleep onset latency (P = 0.02) and serum cortisol concentration (P = 0.008). Supplementation also resulted in marginally between-group significant reduction in early morning awakening (P = 0.08) and serum magnesium concentration (P = 0.06). Although total sleep time (P = 0.37) did not show any significant between-group differences.
Supplementation of magnesium appears to improve subjective measures of insomnia such as ISI score, sleep efficiency, sleep time and sleep onset latency, early morning awakening, and likewise, insomnia objective measures such as concentration of serum renin, melatonin, and serum cortisol, in elderly people.
PMID: 23853635 [PubMed] PMCID: PMC3703169