Association of magnesium depletion score with cognitive function in older adults: An analysis of US National Health and Nutrition Examination Survey (NHANES) 2011 to 2014.
Level 4 - case-series / case-control
Cross-sectional observational study
PubMed 41189251 · doi:10.1097/MD.0000000000045231
What was done
A cross-sectional analysis evaluated 768 participants aged 60 years and older from the 2011 to 2014 National Health and Nutrition Examination Survey (NHANES). Participants were categorized by Magnesium Depletion Score (MDS): none-to-low (0–1), moderate (2), and high (3–5). Cognitive performance was measured using the Digit Symbol Substitution Test (DSST), Animal Fluency Test (AFT), and Consortium to Establish a Registry for Alzheimer's Disease (CERAD) Word Learning subtest. Sample-weighted multivariable linear regression calculated β coefficients (95% confidence intervals), adjusting for age, sex, race, education, income, body mass index (BMI), smoking, and hypertension.
What was found
In fully adjusted models, participants in the high MDS group had significantly lower cognitive scores compared with the none-to-low group: - DSST: β = -4.91 (95% CI: -7.73 to -2.08, P = .0007) - AFT: β = -2.09 (95% CI: -3.25 to -0.93, P = .0004) - CERAD: β = -0.96 (95% CI: -2.25 to 0.33, P = .1445; not statistically significant) Stratified analyses showed stronger associations in participants with BMI > 30 kg/m² and current smokers. Meeting the dietary magnesium Recommended Dietary Allowance (RDA) significantly attenuated risks for DSST (interaction P = .022) and AFT (interaction P = .015).
Why it matters
This study suggests that a higher estimated risk of magnesium depletion is linked to poorer processing speed and executive function in older adults, while meeting dietary magnesium guidelines may help mitigate these cognitive deficits.
Limits
The study's cross-sectional design prevents establishing causal or temporal relationships between magnesium depletion and cognitive decline. Findings are based on brief screening batteries rather than comprehensive clinical neurocognitive diagnoses. Potential residual confounding from unmeasured dietary factors, medications, or comorbid health conditions cannot be ruled out.
Cited by
- supports Studies show that individuals with lower dietary magnesium intakes tend on average to perform less well on cognitive function tests.