Dietary Patterns and Cognition in US Older Adults

Abstract

Abstract Objectives Community-based population cohort studies found that following healthy dietary patterns is protective against cognitive decline in older adults. The current study aims to confirm the associations in nationally representative samples. Methods The current cross-sectional study included 2864 participants (≥60 years) of National Health and Nutrition Examination Survey (NHANES) 2011–2014 who completed both dietary and cognitive assessments. Self-reported dietary intake was collected by trained interviewers using the USDA's Automated Multiple-Pass Method in two nonconsecutive 24-hour dietary recalls. Mediterranean-type Diet (MeDi) and Healthy Eating Index 2015 (HEI15) scores were estimated from the mean intakes of the two diet recalls. Cognitive function was measured by the Consortium to Establish a Registry for Alzheimer's disease Word Learning sub-test (WL), Animal Fluency test (AF), and Digit Symbol Substitution test (DSST). Age, sex, race/ethnicity adjusted z-scores were calculated for three cognitive scores, which were then averaged to get a composite cognitive score. Linear regression models were applied to examine the associations of diet and cognition, adjusted for age, sex, education, race/ethnicity, caloric intake, survey cycles, and annual household income. Results MeDi and HEI2015 were associated with 0.028 (95% CI = 0.004–0.05; P = 0.023) and 0.004 (0.0002–0.007; P = 0.038) higher mean cognitive z-score, respectively. Compared to the lowest tertile of MeDi, the highest tertile of MeDi was associated with 0.141 (95% CI = 0.029–0.253, P = 0.015; p-trend = 0.016) higher mean cognitive z-score. Compared to the lowest tertile, the highest MeDi tertile was associated with 1.001 (0.161–1.840, 0.021; 0.021), 1.05 (0.227–1.875, 0.014; 0.015) and 3.02 (1.004–5.027, 0.005; 0.004) higher WL, AF, and DSST, respectively, and the highest HEI15 tertile was associated with 0.827 (0.154–1.499, 0.018; 0.018) higher AF. The effect size of the highest compared to the lowest tertile of dietary score was approximately equivalent to 3–4 less years of aging. Conclusions Following a healthy diet is associated with better cognitive performance in a nationally representative sample of older adults. Funding Sources The current study was supported by grants from National Institution on Aging.