US Older Adults That Consume Avocado or Guacamole Have Better Cognition Than Non-consumers: National Health and Nutrition Examination Survey 2011–2014

Abstract

Purpose: The goal of this study is to examine how avocado relates to cognitive function among older adults.Methods: A total of 2,886 National Health and Nutrition Examination Survey 2011–2014 participants aged 60 or older met the eligibility criteria and were included of our cross-sectional study. Participants were binarily classified as avocado consumers (i.e., reported consuming any avocado/guacamole in either 24-h dietary recalls) or non-consumers. Cognitive performance was evaluated with: Consortium to Establish a Registry for Alzheimer's disease (CERAD)—immediate and delayed recall (IWR/DWR), the Animal Fluency test, and the Digit Symbol Substitution Test. We calculated the education-dependent z-scores for each subject because education level can impact cognitive function. Global cognitive score, an average of the z-scores for each cognitive test, was calculated in participants who had completed all four tests. To account for relevant covariates, we tested for mean differences in cognition between consumers and non-consumers using independent sample t-tests and ANCOVA, special cases of ordinary least squares regression.Results: Avocado consumers had significantly better cognitive scores across all cognitive tests and the global cognition score (p < 0.05) in the unadjusted model. Some mean differences attenuated after adjusting for potential confounders, but others remained significant. Compared to non-consumers, avocado consumers had significantly higher z-scores of 0.15, 0.15, and 0.11 for CERAD IWR and DWR, and global cognition score, respectively (all p < 0.05 in adjusted models).Conclusion: Avocado consumption was associated with significantly better IWR, DWR, and the overall global cognition score, which remained significant when controlling for all relevant confounders.

A Comprehensive Review of Hass Avocado Clinical Trials, Observational Studies, and Biological Mechanisms

“…Similar findings were observed in an analysis of NHANES 2011-2014 participants aged 60 or older comparing avocado consumers to non-consumers. Specifically, avocado consumers had significantly higher z-scores for Consortium to Establish a Registry for Alzheimer's disease-immediate and delayed recall, and global cognition score, respectively (all p < 0.05 in adjusted models) [33]. More extensive and more prolonged trials are warranted to confirm these findings.…”

“…This study presents the first comprehensive review of Hass avocado clinical trials, observational studies, and biological mechanisms. We found that the Hass avocado has four major health benefits (Figure 17): (1) cardiovascular health [12][13][14][15][16][17][18][19][20][21][22]; (2), weight control [23][24][25][26][27][28][29][30]; (3) cognitive health [18,31,33]; and (4) colonic microbiota health [26,34]. We also found that four nutritional features were primarily responsible for all the major avocado health benefits: (1) high unsaturated to saturated fat ratio [7]; (2) viscous and prebiotic fiber [2,7]; (3) a relatively low energy density of 1.6 kcal/g [7]; and (4) high carotenoid bioavailability [35,36].…”

“…Two clinical trials [18,31] and one cross-sectional analysis [33] support the beneficial effects of avocado on cognitive function. These clinical trials found that avocado intake modestly improved cognitive function in older adults with normal weight after 6 months and in young to middle-aged overweight or obese adults after 3 months.…”

“…Lutein and zeaxanthin can cross the blood-brain barrier and direct their antioxidant and anti-inflammatory functions to act directly on the brain structure and function with selective distribution to the prefrontal cortex, visual cortex, hippocampus, and central retina, as measured by macular pigment optical density [87][88][89][90][91][92]. The concentration of lutein in the brain is higher in the prefrontal cortex than other regions and positively correlated with the gray matter volume in the parahippocampal gyrus, suggesting that lutein plays a role in memory and inhibition functions [18,31,33,[90][91][92].…”

Extra-virgin Avocado (Persea americana Mill.,Laucaceae) Oil Improves Cognitive Impairment in D-galactose-induced Alzheimer’s Disease Model on Ovariectomized Wistar Rat

“…Its consumption is increasing signi cantly worldwide and it provides a lipid pro le almost identical to olive oil (21). Cheng et al (22) reported that American seniors who consumed avocado had improved cognitive performance than non-consumers.…”