Associations between dietary B vitamin intakes and cognitive function among elderly individuals: An observational study

Abstract

Objectives

This study aimed to investigate the associations between dietary B vitamin intakes and the prevalence of cognitive impairment among elderly individuals in the United States.

Methods

This cross-sectional analysis, based on data from 2716 participants aged 60 years or older in the National Health and Nutrition Examination Survey 2011 to 2014. Dietary intakes of six B vitamins (vitamins B1, B2, niacin, B6, total folate, and B12) were assessed using two 24-hour dietary recalls. Cognitive function was evaluated through the Consortium to Establish a Registry for Alzheimer's Disease word list learning test, the Animal Fluency Test, and the Digit Symbol Substitution Test. Associations between dietary B vitamin intakes and cognitive impairment were analyzed using multivariable logistic regression, restricted cubic spline regression, and weighted quantile sum regression.

Results

Higher dietary intakes of B vitamins were inversely associated with the prevalence of cognitive impairment. Participants in the highest quartile of intake showed reduced odds of cognitive impairment compared to the lowest quartile for vitamin B1 (OR = 0.53, 95% CI: 0.29–0.97), vitamin B2 (OR = 0.54, 95% CI: 0.29–1.02), niacin (OR = 0.32, 95% CI: 0.15–0.65), vitamin B6 (OR = 0.45, 95% CI: 0.26–0.79), total folate (OR = 0.53, 95% CI: 0.31–0.89), and vitamin B12 (OR = 0.48, 95% CI: 0.25–0.95). Restricted cubic spline analysis showed linear and inverse exposure-response relationships for all six vitamins without evidence of non-linearity. The weighted quantile sum regression indicated a combined protective effect of dietary B vitamins on cognitive impairment (OR = 0.76, 95% CI: 0.65–0.89), with niacin contributing most to the association (weight: 0.48).

Conclusions

Higher dietary B vitamin intakes may be linked to a lower prevalence of cognitive impairment among older adults in the US. These findings suggest that adequate consumption of dietary B vitamins may be beneficial for maintaining cognitive health. Further, longitudinal studies are needed to confirm these associations.