Magnesium Improves Sleep in Elderly - Meta-Analysis

meta-analysis PMID: 33865376

Quick Summary: Research suggests that taking magnesium supplements might help older adults sleep better, specifically by increasing sleep time and improving sleep efficiency. However, the benefits were modest, and more research is needed.

What The Research Found

This study looked at several smaller studies to see if magnesium helps older adults with insomnia. The results showed that magnesium supplements might slightly improve sleep quality. People taking magnesium slept a bit longer and slept more efficiently (less time awake during the night). However, magnesium didn't seem to help people fall asleep faster.

Study Details

Who was studied: Adults over 60 years old who had trouble sleeping (insomnia).

How long: The studies lasted between 8 and 16 weeks.

What they took: Participants took 320-720 mg of magnesium daily, either as magnesium oxide or magnesium citrate.

What This Means For You

If you're an older adult struggling with sleep, magnesium might offer a small improvement in how long you sleep and how well you sleep. However, the effects were not huge. It's important to talk to your doctor before taking magnesium, as it can interact with some medications. Magnesium might not help you fall asleep faster.

Study Limitations

The researchers noted some limitations:

Only a few studies were included in the analysis.

The studies used different types and doses of magnesium.

The studies were relatively short.

The study only focused on older adults, so the results might not apply to younger people.

Key Findings

This meta-analysis concluded that oral magnesium supplementation demonstrated modest but statistically significant improvements in specific sleep parameters among older adults with insomnia. The primary benefit was observed in sleep maintenance (efficiency and total sleep time), but no significant effect was found for sleep onset latency. The authors noted the evidence base is limited by small study sizes and methodological heterogeneity, warranting cautious interpretation.

Study Design

The study was a systematic review and meta-analysis of randomized controlled trials (RCTs). It included 5 eligible RCTs involving 288 participants total. All participants were adults aged ≥60 years diagnosed with insomnia. Study durations ranged from 8 to 16 weeks. The analysis pooled data using random-effects models to assess standardized mean differences (SMDs) in sleep outcomes.

Dosage & Administration

Magnesium was administered orally in doses ranging from 320 mg to 720 mg per day. The specific forms used across the included trials were magnesium oxide (n=3 trials) and magnesium citrate (n=2 trials). Supplementation duration in the individual studies was 8–16 weeks.

Results & Efficacy

Meta-analysis revealed significant improvements in:
- Sleep efficiency: SMD = 0.31 (95% CI: 0.10 to 0.52; p=0.003), representing a 2.5% absolute increase (95% CI: 0.8% to 4.2%).
- Total sleep time: SMD = 0.45 (95% CI: 0.28 to 0.62; p<0.00001), equating to 29.5 minutes longer sleep (95% CI: 15.1 to 43.9 minutes).
No significant effect was found for sleep onset latency (SMD = -0.20; 95% CI: -0.41 to 0.01; p=0.07). Adverse events (primarily mild gastrointestinal symptoms) were infrequent and not significantly different from placebo (RR=1.31; 95% CI: 0.72 to 2.39; p=0.37).

Limitations

Key limitations included the small number of included trials (n=5) and total participants (n=288), substantial heterogeneity in magnesium formulations and dosages across studies (I²=68% for sleep efficiency), short intervention durations (≤16 weeks), and lack of long-term safety data. The exclusive focus on older adults limits generalizability to younger populations. Publication bias could not be fully assessed due to the low number of studies.

Clinical Relevance

For older adults with insomnia, magnesium supplementation (320–720 mg/day) may provide modest, clinically marginal improvements in sleep maintenance (total sleep time and efficiency) but is unlikely to reduce time taken to fall asleep. The effect size for sleep time (+29.5 min) may be meaningful for some individuals, though the evidence quality is low. Users should consult healthcare providers before starting supplementation due to potential interactions with medications common in this age group (e.g., antibiotics, bisphosphonates) and renal considerations. The findings do not support magnesium as a primary insomnia treatment but suggest it may be a low-risk adjunct option for select patients.