Dietary selenium intake, hypertension and cognitive function among US adults, NHANES 2011-2014

Dietary selenium intake and hypertension were associated with cognitive function, but it was limitedly understood whether the effect of selenium intake on cognitive function in older adults was modified by hypertension status. A total of 2416 participants aged ≥ 60 years old from the National Health and Nutrition Examination Survey in 2011-2014 were involved in this study. Selenium intake from foods was estimated using two non-consecutive 24-hour dietary recalls. Blood pressure was measured by trained personnel or physicians at a mobile testing center. Cognitive function was measured by Registry for Alzheimer's disease (CERAD), the Animal Fluency test (AFT), and Digit Symbol Substitution Test (DSST). Among 2,416 participants, we found that higher dietary intake of selenium was associated with higher score on most tests (CERAD: Total Score: P for trend = 0.01; AFT: P for trend = 0.01; DSST: P for trend = 0.02) and hypertension was associated with lower score on each test (CEARD: Total Score (β = - 0.87, P = 0.03), CERAD: Delayed Recall Score (β = - 0.37, P = 0.04), AFT (β = - 0.88, P = 0.03), and DSST (β = - 2.72, P = 0.02). The interaction of hypertension status and dietary selenium intake on CERAD-immediate (P for interaction = 0.02) and DSST (P for interaction = 0.04) were statistical significance. In addition, hypertension did not mediate the association between dietary selenium intake and the four dimensions of cognition. The findings suggest that in older adults with hypertension, higher dietary selenium intake is associated with improved cognitive function, implying a potential nutritional strategy for preventing cognitive impairment in this population.