2012

The effect of magnesium supplementation on primary insomnia in elderly: a double-blind placebo-controlled clinical trial

Abbasi B, Kimiagar M, Sadeghniiat K, Shirazi MM, Hedayati M, Rashidkhani B

Published in Journal of Research in Medical Sciences

Abstract

Higher magnesium intake was associated with better sleep quality and reduced insomnia symptoms.

Methodology

Double-blind, placebo-controlled randomised trial in elderly adults with primary insomnia; 500 mg magnesium daily versus placebo for 8 weeks; outcomes were the Insomnia Severity Index, sleep time, sleep efficiency, sleep onset latency, early morning awakening, and serum renin, melatonin and cortisol.

Key Findings

Magnesium significantly increased sleep time and sleep efficiency and reduced Insomnia Severity Index scores, sleep onset latency and early morning awakening compared with placebo. Serum renin and melatonin increased and serum cortisol decreased in the magnesium group.

Conclusions

Eight weeks of 500 mg/day magnesium improved subjective and biochemical measures of insomnia in older adults, supporting magnesium as a low-cost option in this population.

Limitations

Very small single-centre trial (n=46) in elderly Iranian adults; sleep outcomes were largely self-reported without polysomnography; short duration; findings have not been robustly replicated, and this trial is frequently over-cited as evidence for magnesium in the general population.