Healthy dietary patterns are associated with better cognitive performance in older adults: Findings from National Health And Nutrition Examination Survey (NHANES) 2011‐2014

Abstract

AbstractBackgroundIncreasing evidence from community‐based population cohorts suggests that following healthy dietary patterns is protective against cognitive decline, Alzheimer’s disease, or other dementia in older adults. However, such findings have rarely been confirmed in nationally representative samples.MethodThe current study included 2,864 participants (≥60 years) of the 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. Intakes of nutrients and food groups were calculated using reference from the USDA 'Food and Nutrient Database for Dietary Studies' and 'Food Patterns Equivalents Database', 2011‐2014, respectively. 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‐score was calculated for each cognitive score, which were then averaged to get a composite cognitive score. Complex samples plan linear regression models were applied to examine the associations of diet and cognition, adjusted for age, sex, education, race (white/black/Hispanic/others), caloric intake, cycles (2011‐2012 /2013‐2014), and annual household income (< or ≥ $45,000).ResultMeDi and HEI2015 were associated with 0.028 (95%CI=0.004‐0.05, p=0.023) and 0.004 (95%CI=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 (95%CI=0.161‐1.840, p=0.021; p‐trend=0.021), 1.05 (95%CI=0.227‐1.875, p=0.014; p‐trend=0.015) and 3.02 (95%CI=1.004‐5.027, p=0.005; p‐trend=0.004) higher WL, AF, and DSST, respectively, and the highest HEI15 tertile was associated with 0.827 (95%CI=0.154‐1.499, p=0.018; p‐trend=0.018) higher AF. The effect size of the highest tertile of dietary score was approximately equivalent to 3‐4 less years of aging (b of 1‐year aging=‐0.316, ‐0.229, and ‐0.867 for WL, AF, and DSST, respectively).ConclusionFollowing a healthy diet is associated with better cognitive performance in a nationally representative sample of older adults.