The Relationship Between Dietary Sodium Intake and Cognitive Function: A Narrative Review

This narrative review provides discussion on current evidence regarding the relationship between sodium intake and cognitive function in animal and human studies, as well as potential mechanisms underlying this relationship. Recent evidence suggests high sodium intake is associated with development of cognitive impairment and neural dysfunction. Additionally, studies have proposed that high sodium intake is associated with increased aggregation of Aβ-amyloid and that hypertension (for which high sodium intake is a risk factor) modulates the relationship between Aβ-amyloid and development of cognitive impairment and Alzheimer’s disease. However, while animal studies demonstrate a consistent relationship between high sodium intake and cognitive impairment, this relationship remains less clear in humans. Overall, mixed results were observed regarding whether sodium intake is associated with cognitive function. To a certain extent, the findings from this review support the notion that high sodium intake could be having a negative impact on middle and older-aged individuals’ cognitive health. Further exploration of the relationship between dietary sodium intake and cognition is needed in well characterised human cohorts, using comprehensive assessment of cognitive function. Furthermore, given self-report sodium intake can give over- or under-reported levels, the addition of 24-hour urinary sodium levels would enhance research findings and its interpretation.