Abstract
The impact of vitamin B2 (riboflavin) intake on cognitive performance among older adults in the United States (US) remains inadequately understood. This study aimed to explore the association between vitamin B2 intake and cognitive performance among non-institutionalized elderly people in the US. Weighted logistic regression was used to evaluate the association between vitamin B2 intake and cognitive performance. Vitamin B2 intake was determined from the mean of two 24-hour dietary recall interviews. Three cognitive ability assessment tests, namely the Immediate Recall Test (IRT), Animal Fluency Test (AFT), and Digit Symbol Substitution Test (DSST), were performed. Participants included all older adults over 60 who underwent cognitive scoring, with cut-offs defined based on the lowest quartile (25th percentile) for each test (the cut-offs for the three scores were 15.625, 12, and 33, respectively). Sensitivity analysis, including dose-response curves, subgroup analyses, interaction effects, per 1 standard deviation (SD), recommended dietary allowance (RDA), and residual energy model analysis, were performed to solidify the solid association between vitamin B2 and cognitive performance. A total of 2893 individuals aged over 60 were included, with a mean age of 69 (7) years, and 46% were men. There was a significant association between vitamin B2 intake and all three cognitive scores (IRT, Odds Ratio = 0.77, 95% confidence interval: [0.65,0.92]; AFT, 0.75, [0.64,0.88]; DSST, 0.72, [0.59,0.88]). Moreover, vitamin B2 intake above the RDA reduced the risk of low cognitive performance (IRT, 0.66, [0.46,0.93]; AFT, 0.83, [0.62,1.11]; DSST, 0.65, [0.45,0.92]) compared to intake below the RDA. Dose-response curves indicated that higher vitamin B2 intake was negatively associated with the risk of low cognitive performance. Physical activity may modify the association between vitamin B2 and cognitive performance. Vitamin B2 intake was positively associated with cognitive performance among older adults. Adequate vitamin B2 intake could help protect cognitive function.