Magnesium and Cognitive Health in Adults: A Systematic Review and Meta-Analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of randomized controlled trials and cohort studies.
PubMed 39009081 · doi:10.1016/j.advnut.2024.100272
What was done
A systematic review and meta-analysis of studies indexed up to May 3, 2024 across PubMed, Embase, PsycINFO, and Cochrane Central evaluating magnesium forms (supplements, diet, biomarkers) and adult cognitive outcomes. Three random-effects models were conducted: linear meta-regression, quadratic nonlinear meta-regression, and categorical meta-analysis based on standard reference ranges (0.75–0.95 mmol/L).
What was found
Included 3 RCTs and 12 cohort studies. RCT evidence was insufficient to evaluate supplement efficacy. Dietary magnesium showed inconsistent dose-response relationships with high heterogeneity across cohorts. Serum magnesium displayed a U-shaped association with dementia and cognitive impairment (P quadratic = 0.003), with an optimal concentration of ~0.85 mmol/L. Compared with 0.85 mmol/L, pooled hazard ratios were 1.43 (95% CI: 1.05, 1.93) for <0.75 mmol/L and 1.30 (95% CI: 1.03, 1.64) for >0.95 mmol/L.
Why it matters
Demonstrates a nonlinear U-shaped relationship where both low and high serum magnesium concentrations are associated with increased dementia risk, while revealing a stark lack of randomized trial evidence for magnesium supplementation.
Limits
Only 3 RCTs were available, precluding conclusions on supplementation. Cohort dietary findings had high heterogeneity, lacked repeated intake measures, and omitted absorption factors (such as calcium-to-magnesium ratio). Total participant count was not reported in the abstract.
Cited by
- context Studies show that individuals with lower dietary magnesium intakes tend on average to perform less well on cognitive function tests.