Ca:Mg Ratio, APOE Cytosine Modifications, and Cognitive Function: Results from a Randomized Trial

Area of Science:

• Neuroscience
• Nutritional Science
• Epigenetics

Background:

• Impaired calcium (Ca2+) regulation in neurons is linked to neurodegenerative diseases.
• Magnesium (Mg) counteracts Ca2+ in physiological processes, including energy metabolism and DNA demethylation (5-methylcytosine to 5-hydroxymethylcytosine).

Purpose of the Study:

• To investigate if reducing the dietary Ca:Mg ratio via Mg supplementation enhances cognitive function.
• To determine if epigenetic modifications in Apolipoprotein E (APOE) mediate this cognitive improvement.

Main Methods:

• A double-blind, 2x2 factorial randomized controlled trial nested within the Personalized Prevention of Colorectal Cancer Trial (PPCCT).
• 250 participants from Vanderbilt University Medical Center received personalized Mg or placebo doses.
• Analysis focused on individuals aged over 65 with a high Ca:Mg diet.

Main Results:

• Reducing the Ca:Mg ratio to approximately 2.3 through Mg supplementation significantly improved cognitive function by 9.1% in participants over 65 (p=0.03).
• This reduction also significantly decreased 5-methylcytosine (5-mC) levels at specific sites (cg13496662, cg06750524) in the APOE gene (p=0.02, p=0.03).
• The cognitive benefits were partially mediated by reduced 5-mC levels in APOE (p=0.05 for indirect effect).

Conclusions:

• Optimal Mg status may enhance cognitive function in older adults with high dietary Ca:Mg ratios, potentially via APOE methylation changes.
• These findings suggest a novel preventative strategy for cognitive aging and Alzheimer's disease.
• Further research is needed to confirm these implications.