Objectives

To evaluate the association between the Mediterranean diet (MedDiet) and the Mediterranean-DASH diet Intervention for Neurodegeneration Delay (MIND diet) and cognition in a nationally representative population of older U.S. adults.

Design

Population-based cross-sectional study.

Setting

Health and Retirement Study.

Participants

Community-dwelling older adults (N = 5,907; mean age 67.8 ± 10.8).

Measurements

Adherence to dietary patterns was determined from food frequency questionnaires using criteria determined a priori to generate diet scores for the MedDiet (range 0-55) and MIND diet (range 0-15). Cognitive performance was measured using a composite test score of global cognitive function (range 0-27). Linear regression was used to compare cognitive performance according to tertiles of dietary pattern. Logistic regression was used to examine the association between dietary patterns and clinically significant cognitive impairment. Models were adjusted for age, sex, race, educational attainment, and other health and lifestyle covariates.

Results

Participants with mid (odds ratio (OR) = 0.85, 95% confidence interval (CI) = 0.71-1.02, P = .08) and high (OR 0.65, 95% CI = 0.52-0.81, P < .001) MedDiet scores were less likely to have poor cognitive performance than those with low scores in fully adjusted models. Results for the MIND diet were similar. Higher scores in each dietary pattern were independently associated with significantly better cognitive function (P < .001) in a dose-response manner (P _trend  < .001).

Conclusion

In a large nationally representative population of older adults, greater adherence to the MedDiet and MIND diet was independently associated with better cognitive function and lower risk of cognitive impairment. Clinical trials are required to elucidate the role of dietary patterns in cognitive aging.

Aging is the biggest risk factor for the development of chronic diseases. Telomere length may represent one important mechanism by which dietary intake influences risk of age-related diseases; however, it is unknown which diet pattern is most strongly related to telomere length. We compared the relationships between 4 evidence-based diet quality indices and leukocyte telomere length in a nationally representative sample of healthy adults, and the extent to which these associations differed between men and women. Data on 4,758 adults aged 20-65 years with no prior diagnosis of major chronic disease were obtained from the 1999-2002 cycles of the National Health and Nutrition Examination Survey. Diet was assessed using one 24-hour dietary recall. After adjustment for sociodemographic and health characteristics, comparison of the top and bottom quintiles showed that higher Healthy Eating Index 2010 scores (β = 0.065, 95% confidence interval (CI): 0.018, 0.112; P-trend = 0.007), Alternate Healthy Eating Index 2010 scores (β = 0.054, 95% CI: 0.010, 0.097; P-trend = 0.007), Mediterranean Diet scores (β = 0.058, 95% CI: 0.017, 0.098; P-trend = 0.008), and Dietary Approaches to Stop Hypertension (DASH) scores (β = 0.052, 95% CI: 0.014, 0.090; P-trend = 0.007) were each associated with longer telomere length in women. These results may provide insight into the complex associations between optimal nutrition and longevity. Further investigation is needed to understand why associations were not observed in men.

Abstract

Alzheimer disease (AD) is the most common type of dementia characterized by the progressive cognitive and social decline. Clinical drug targets have heavily focused on the amyloid hypothesis, with amyloid beta (Aβ), and tau proteins as key pathophysiologic markers of AD. However, no effective treatment has been developed so far, which prompts researchers to focus on other aspects of AD beyond Aβ, and tau proteins. Additionally, there is a mounting epidemiologic evidence that various environmental factors influence the development of dementia and that dementia etiology is likely heterogenous. In the past decades, new risk factors or potential etiologies have been widely studied. Here, we review several novel epidemiologic and clinical research developments that focus on sleep, hypoxia, diet, gut microbiota, and hearing impairment and their links to AD published in recent years. At the frontiers of AD research, these findings and updates could be worthy of further attention.

Objective

To investigate whether dietary patterns (Mediterranean diet [MedDiet], Dietary Approaches to Stop Hypertension [DASH], and A Priori Diet Quality Score [APDQS]) during adulthood are associated with midlife cognitive performance.

Methods

We studied 2,621 Coronary Artery Risk Development in Young Adults (CARDIA) participants; 45% were black, 57% were female, and mean age was 25 ± 3.5 years at baseline (year 0). Mean diet scores were calculated from diet history at baseline, year 7, and year 20 (mean age 25, 32, and 45 years, respectively). Cognitive function was assessed at years 25 and 30 (mean age 50 and 55 years, respectively). Linear models were used to examine association between tertiles of diet score and change in composite cognitive function and cognitive z scores (verbal memory [Rey Auditory Verbal Learning Test], processing speed [Digit Symbol Substitution Test], and executive function [Stroop Interference test]) and the Montreal Cognitive Assessment (MoCA) at year 30.

Results

DASH was not associated with change in cognitive performance. Higher MedDiet and APDQS scores were associated with less decline in cognitive function (MedDiet: low -0.04, middle 0.03, high 0.03, p = 0.03; APDQS: low -0.04, middle -0.00, high 0.06, p < 0.01) and Stroop Interference (MedDiet: low 0.09, middle -0.06, high -0.03; APDQS: low 0.10, middle 0.01, high -0.09, both p < 0.01). Odds ratios (95% confidence interval) for poor global cognitive function (≥1 SD below mean MoCA score) comparing extreme tertiles of diet scores were 0.54 (0.39-0.74) for MedDiet, 0.48 (0.33-0.69) for APDQS, and 0.89 (0.68-1.17) for DASH.

Conclusion

Greater adherence to MedDiet and APDQS dietary patterns during adulthood was associated with better midlife cognitive performance. Additional studies are needed to define the combination of foods and nutrients for optimal brain health across the life course.