Magnesium Status in Alzheimer's Disease: A Systematic Review

The interest in poor magnesium (Mg) status as risk factor for Alzheimer's disease (AD) is increasing due to its antioxidant and neuroprotective properties. A systematic PubMed literature search of studies investigating Mg status was undertaken comparing AD to healthy controls (HCs) or patients with medical illness (medical controls [MCs]). Standardized mean differences (SMDs) +/- 95% confidence intervals (CIs) were calculated for all outcomes. Of 192 potentially eligible studies, 13 were included (559 patients with AD, 381 HCs, and 126 MCs). Compared to HCs, patients with AD had significantly lower Mg in cerebrospinal fluid (2 studies; SMD = -0.35; P = .02) and in hair (2 studies; SMD = -0.75; P = .0001). No differences between AD and controls were evident for serum Mg. In conclusion, AD seems to be associated with a lower Mg status when compared to HCs, while the scarcity of studies limited the findings about MCs.