A cross-sectional study of blood selenium concentration and cognitive function in elderly Americans: National Health and Nutrition Examination Survey 2011-2014

Background Cognitive decline can develop into mild cognitive impairment, a high-risk factor in the progression of Alzheimer's disease. The antioxidant micronutrient selenium may have some effect on preventing cognitive decline, but the association between whole blood selenium concentration and cognitive function remains controversial. Aim To investigate the association between whole blood selenium concentration and cognitive function score in elderly Americans. Subjects and methods Data was obtained from the national health and nutrition survey between 2011 and 2014. A general linear model was used to adjust for possible risk factors to analyse the association between blood selenium concentration and cognitive function. Results 2068 participants were included in our study, and the average blood selenium concentration was high at 195.08 mu g/L. The risk of lower cognitive scores was higher in people with lower blood selenium concentration (p < 0.05). The lower cognition may also be associated with one or more of the following characteristics: older, male, had a low poverty-income ratio, low education level, and consumed less alcohol. Related conditions such as stroke, diabetes and high blood pressure may also affect cognitive scores. Conclusions Higher blood selenium is associated with higher cognitive scores in elderly Americans.