Written by Chrystal Moulton, Science Writer. Researchers found that albumin and vitamin D significantly mediated the link between selenium intake and cognition (P < 0.01).
Selenium is an essential trace mineral that plays a pivotal role in cognition1,2. Selenium deficiency is linked to dementia and recent studies on adults over 65 years of age showed that increased selenium intake is associated with higher cognitive functioning3,4. Given evidence of the role that selenium has in cognition, researchers in this analysis evaluated the association between selenium intake and cognitive functioning utilizing population based data from the National Health and Nutrition Examination Survey (NHANES)5.
The National Health and Nutrition Examination Survey (NHANES) is an annual survey collecting health, medical, and nutritional information from volunteers in the US. Volunteers meet with clinical specialists who conduct the interviews and assessments. In this study, researchers used data from the 2011-2014 NHANES cycle. Of 19,931 individuals surveyed, 2,154 were eligible for this analysis. Selenium intake was assessed through two 24hour dietary recall interviews: one conducted in person and the other via phone call 3-10 days later. Cognitive function was assessed used 3 tests:
- Consortium to Establish a Registry for Alzheimer’s disease (CERAD): participants were expected to recall words presented on a screen.
- Animal fluency test: participants were asked to name as many items they can based on a category provided i.e. articles or clothing, animals, etc.
- Digital Symbol Substitution Test (DSST): participants were required to match symbols to numbers
Total scores in all 3 tests were used as the participants general cognition score. Individuals with the lowest scores were categorized into quartile 1. Logistical regression models were applied with confounders to determine potential associations.
Of 2,154 eligible participants, 754 took selenium supplements. Baseline characteristics between individuals with cognitive impairment and individuals without cognitive impairments showed significant differences in age, income, drinking status, education, marital status, race, and selenium intake. Specifically, selenium intake was higher among individuals without cognitive impairment (P < 0.01). Other significant differences between normal versus cognitively impaired participants were levels of albumin, uric acid, vitamin D, and gamma-glutamyl transpeptidase (GGT) as well as the occurrence of coronary heart disease, stroke, hypertension, and diabetes, which as higher in the cognitively impaired group (P ≤ 0.05). After adjusting for all baseline characteristics in the logistical model, researchers observed a positive association between selenium intake and cognition (OR = 1.004, P = 0.019). In relation to oxidative stress, researchers observed a significant positive association between cognition and albumin (OR = 2.073, P = 0.015) and vitamin D (OR = 1.005, P = 0.007) after adjusting for all confounders. A significant negative association was observed for GGT (OR = 0.994, P = 0.030) after adjusting for all confounders. Further analysis also showed a significant positive relationship between selenium intake, albumin (P = 0.006) and vitamin D (P = 0.051) along with a significant negative relationship with selenium intake and uric acid levels (P = 0.025). Researchers also found that albumin and vitamin D significantly mediated the link between selenium intake and cognition (P < 0.01).
Details from this analysis verified existing research demonstrating a significant positive association between selenium intake and cognitive functioning. Furthermore, researchers found that both albumin and vitamin D mediated the link between selenium and cognition. Additional studies will be needed to verify these findings.
Source: Li, Jia-Meng, Ya-Zhi Bai, Quan-Ying Liu, and Shuang-Qing Zhang. “Mediation Effect of Oxidative Stress on Association Between Selenium Intake and Cognition in American Adults.” Nutrients 16, no. 23 (2024): 4163.
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Posted January 16, 2025.
Chrystal Moulton BA, PMP, is a 2008 graduate of the University of Illinois at Chicago. She graduated with a bachelor’s in psychology with a focus on premedical studies and is a licensed project manager. She currently resides in Indianapolis, IN.
References:
- Li JM, Bai YZ, Zhang SQ. Roles of selenium in cognition. International journal for vitamin and nutrition research Internationale Zeitschrift fur Vitamin- und Ernahrungsforschung Journal international de vitaminologie et de nutrition. Jun 2024;94(5-6):323-324. doi:10.1024/0300-9831/a000792
- Bai YZ, Zhang Y, Zhang SQ. New horizons for the role of selenium on cognitive function: advances and challenges. Metab Brain Dis. Aug 2024;39(6):1255-1268. doi:10.1007/s11011-024-01375-y
- Alehagen U, Opstad TB, Alexander J, Larsson A, Aaseth J. Impact of Selenium on Biomarkers and Clinical Aspects Related to Ageing. A Review. Biomolecules. Oct 7 2021;11(10)doi:10.3390/biom11101478
- Ferdous KA, Knol LL, Park HA. Association between selenium intake and cognitive function among older adults in the US: National Health and Nutrition Examination Surveys 2011-2014. J Nutr Sci. 2023;12:e57. doi:10.1017/jns.2023.43
- Li JM, Bai YZ, Liu QY, Zhang SQ. Mediation Effect of Oxidative Stress on Association Between Selenium Intake and Cognition in American Adults. Nutrients. Nov 30 2024;16(23)doi:10.3390/nu16234163
