Adequate dietary magnesium intake may protect females but not males older than 55 years from cognitive impairment

BackgroundMagnesium is an essential nutrient required to maintain brain health throughout life, and adequate magnesium intake is positively associated with cognitive performance in older adults. However, sex differences in magnesium metabolism have not been adequately assessed in humans.ObjectivesWe investigated sex differences in the effect of dietary magnesium intake and the risk of different types of cognitive impairment in older Chinese adults.MethodsWe collected and assessed dietary data and cognitive function status in people aged 55 years and older in northern China who participated in the Community Cohort Study of Nervous System Diseases from 2018 to 2019 to explore the relationship between dietary magnesium intake and the risk of each type of mild cognitive impairment (MCI) in sex-specific cohorts of older adults.ResultsThe study included 612 people: 260 (42.5%) men and 352 (57.5%) women. Logistic regression results showed that for the total sample and women's sample, high dietary magnesium intake reduced the risk of amnestic MCI (ORtotal = 0.300; ORwomen = 0.190) and multidomain amnestic MCI (ORtotal = 0.225; ORwomen = 0.145). The results of restricted cubic spline analysis showed that the risk of amnestic MCI (p(total) = 0.0193; p(women) = 0.0351) and multidomain amnestic MCI (p(total) = 0.0089; p(women) = 0.0096) in the total sample and women's sample gradually decreased with increasing dietary magnesium intake.ConclusionsThe results suggest that adequate magnesium intake may have a preventive effect against the risk of MCI in older women.