Christy C. Tangney

MIND diet associated with reduced incidence of Alzheimer's disease

In a previous study, higher concordance to the MIND diet, a hybrid Mediterranean‐Dietary Approaches to Stop Hypertension diet, was associated with slower cognitive decline. In this study we related these three dietary patterns to incident Alzheimers disease (AD).

Polyphenols, Inflammation, and Cardiovascular Disease

Polyphenols are compounds found in foods such as tea, coffee, cocoa, olive oil, and red wine and have been studied to determine if their intake may modify cardiovascular disease (CVD) risk. Historically, biologic actions of polyphenols have been attributed to antioxidant activities, but recent evidence suggests that immunomodulatory and vasodilatory properties of polyphenols may also contribute to CVD risk reduction. These properties will be discussed, and recent epidemiological evidence and intervention trials will be reviewed. Further identification of polyphenols in foods and accurate assessment of exposures through measurement of biomarkers (i.e., polyphenol metabolites) could provide the needed impetus to examine the impact of polyphenol-rich foods on CVD intermediate outcomes (especially those signifying chronic inflammation) and hard endpoints among high risk patients. Although we have mechanistic insight into how polyphenols may function in CVD risk reduction, further research is needed before definitive recommendations for consumption can be made.

MIND diet slows cognitive decline with aging.

The Mediterranean and dash diets have been shown to slow cognitive decline; however, neither diet is specific to the nutrition literature on dementia prevention.

Relation of DASH- and Mediterranean-like dietary patterns to cognitive decline in older persons

Objectives: We examined whether accordance to the DASH (Dietary Approach to Stop Hypertension) and Mediterranean diets is associated with slower cognitive decline in a prospective Chicago cohort study of older persons, the Memory and Aging Project. Methods: The sample comprised 826 Memory and Aging Project participants (aged 81.5 ± 7.1 years) who completed a 144-item food frequency questionnaire at baseline and 2 or more cognitive assessments over 4.1 years. Dietary scores were computed for accordance to the DASH diet (0–10) and the Mediterranean diet (MedDietScore) (0–55). For both, higher scores reflect greater accordance. Both patterns share at least 3 common food components. Cognitive function was assessed annually with 19 cognitive tests from which global cognitive scores and summary measures are computed. Results: The mean global cognitive score at baseline was 0.12 (range, −3.23 to 1.60) with an overall mean annual change in score of −0.08 standardized units. Only 13 participants had possible dementia. The mean DASH score was 4.1 (range, 1.0–8.5) and the MedDietScore was 31.3 (range, 18–46). In mixed models adjusted for covariates, a 1-unit difference in DASH score was associated with a slower rate of global cognitive decline by 0.007 standardized units (standard error of estimate = 0.003, p = 0.03). Similarly, a 1-unit-higher MedDietScore was associated with a slower rate of global cognitive decline by 0.002 standardized units (standard error of estimate = 0.001, p = 0.01). Conclusions: These findings support the hypothesis that both the DASH and Mediterranean diet patterns are associated with slower rates of cognitive decline in the same cohort of older persons.

Association of Seafood Consumption, Brain Mercury Level, and APOE ε4 Status With Brain Neuropathology in Older Adults

IMPORTANCE Seafood consumption is promoted for its many health benefits even though its contamination by mercury, a known neurotoxin, is a growing concern. OBJECTIVE To determine whether seafood consumption is correlated with increased brain mercury levels and also whether seafood consumption or brain mercury levels are correlated with brain neuropathologies. DESIGN, SETTING, AND PARTICIPANTS Cross-sectional analyses of deceased participants in the Memory and Aging Project clinical neuropathological cohort study, 2004-2013. Participants resided in Chicago retirement communities and subsidized housing. The study included 286 autopsied brains of 554 deceased participants (51.6%). The mean (SD) age at death was 89.9 (6.1) years, 67% (193) were women, and the mean (SD) educational attainment was 14.6 (2.7) years. EXPOSURES Seafood intake was first measured by a food frequency questionnaire at a mean of 4.5 years before death. MAIN OUTCOMES AND MEASURES Dementia-related pathologies assessed were Alzheimer disease, Lewy bodies, and the number of macroinfarcts and microinfarcts. Dietary consumption of seafood and n-3 fatty acids was annually assessed by a food frequency questionnaire in the years before death. Tissue concentrations of mercury and selenium were measured using instrumental neutron activation analyses. RESULTS Among the 286 autopsied brains of 544 participants, brain mercury levels were positively correlated with the number of seafood meals consumed per week (ρ = 0.16; P = .02). In models adjusted for age, sex, education, and total energy intake, seafood consumption (≥ 1 meal[s]/week) was significantly correlated with less Alzheimer disease pathology including lower density of neuritic plaques (β = -0.69 score units [95% CI, -1.34 to -0.04]), less severe and widespread neurofibrillary tangles (β = -0.77 score units [95% CI, -1.52 to -0.02]), and lower neuropathologically defined Alzheimer disease (β = -0.53 score units [95% CI, -0.96 to -0.10]) but only among apolipoprotein E (APOE ε4) carriers. Higher intake levels of α-linolenic acid (18:3 n-3) were correlated with lower odds of cerebral macroinfarctions (odds ratio for tertiles 3 vs 1, 0.51 [95% CI, 0.27 to 0.94]). Fish oil supplementation had no statistically significant correlation with any neuropathologic marker. Higher brain concentrations of mercury were not significantly correlated with increased levels of brain neuropathology. CONCLUSIONS AND RELEVANCE In cross-sectional analyses, moderate seafood consumption was correlated with lesser Alzheimer disease neuropathology. Although seafood consumption was also correlated with higher brain levels of mercury, these levels were not correlated with brain neuropathology.

Brain tocopherols related to Alzheimer's disease neuropathology in humans

Randomized trials of α‐tocopherol supplements on cognitive decline are negative, whereas studies of dietary tocopherols have shown benefit. We investigated these inconsistencies by analyzing the relations of α‐ and γ‐tocopherol brain concentrations to Alzheimers disease (AD) neuropathology among 115 deceased participants of the prospective Rush Memory and Aging Project. Associations of amyloid load and neurofibrillary tangle severity with brain tocopherol concentrations were examined in separate adjusted linear regression models. γ‐Tocopherol concentrations were associated with lower amyloid load (β = ‒2.10, P = .002) and lower neurofibrillary tangle severity (β = ‒1.16, P = .02). Concentrations of α‐tocopherol were not associated with AD neuropathology, except as modified by γ‐tocopherol: high α‐tocopherol was associated with higher amyloid load when γ‐tocopherol levels were low and with lower amyloid levels when γ‐tocopherol levels were high (P for interaction = 0.03). Brain concentrations of γ‐ and α‐tocopherols may be associated with AD neuropathology in interrelated, complex ways. Randomized trials should consider the contribution of γ‐tocopherol.

DASH and Mediterranean-Type Dietary Patterns to Maintain Cognitive Health

There is growing consensus that as the U.S. population ages, nearly a third will experience stroke, dementia, or even both. Thus, interest in the role that diet may play in preserving cognitive abilities continues to grow, especially in absence of truly effective treatments for dementia, of which Alzheimer’s disease (AD) is the most common form. The purpose of this review is to examine whether two a priori dietary patterns influence the rate of cognitive decline or the onset of dementia. Evidence from neuropathology reports of those who have died with AD or with mild cognitive impairment (MCI) or without cognitive impairment suggests that often the pathological hallmarks of AD—amyloid deposition and presence of tangles—are present along with vascular lesions. Hypertension and stroke are strongly associated with incident dementia. Thus, it is possible that lifestyle approaches designed to prevent or reduce cardiovascular risk factors, conditions, or diseases also may provide added benefits for brain health.

Vitamin B12 Deficiency in Relation to Functional Disabilities

This study was designed to assess whether symptoms, functional measures, and reported disabilities were associated with vitamin B12 (B12) deficiency when defined in three ways. Participants, aged 60 or more years of age, in 1999–2002 National Health and Nutrition Examination Surveys (NHANES) were categorized in relation to three previously used definitions of B12 deficiency: (1) serum B12 < 148 pmol/L; (2) serum B12 < 200 pmol/L and serum homocysteine > 20 μmol/L; and (3) serum B12 < 258 pmol/L or serum methylmalonic acid > 0.21 μmol/L. Functional measures of peripheral neuropathy, balance, cognitive function, gait speed, along with self-reported disability (including activities of daily living) were examined with standardized instruments by trained NHANES interviewers and technicians. Individuals identified as B12 deficient by definition 2 were more likely to manifest peripheral neuropathy OR (odds) (95% confidence intervals), p value: 9.70 (2.24, 42.07), 0.004 and report greater total disability, 19.61 (6.22, 61.86) 0.0001 after adjustments for age, sex, race, serum creatinine, and ferritin concentrations, smoking, diabetes, and peripheral artery disease. Smaller, but significantly increased, odds of peripheral neuropathy and total disability were also observed when definition 3 was applied. Functional measures and reported disabilities were associated with B12 deficiency definitions that include B12 biomarkers (homocysteine or methylmalonic acid). Further study of these definitions is needed to alert clinicians of possible subclinical B12 deficiency because functional decline amongst older adults may be correctable if the individual is B12 replete.

Analysis of Postmortem Ventricular Cerebrospinal Fluid from Patients with and without Dementia Indicates Association of Vitamin E with Neuritic Plaques and Specific Measures of Cognitive Performance

Ventricular cerebrospinal fluid (vCSF) obtained at autopsy from 230 participants in the Religious Orders Study was analyzed for alpha tocopherol (αT, vitamin E) and gamma tocopherol (γT) in relation to brain tissue neuropathological diagnoses (NIA-Reagan criteria); neuritic plaque density and neurofibrillary tangle state (Braak stage); and cognitive function proximate to death. Neither vCSF αT nor γT was related to the pathological diagnosis of Alzheimers disease, but vCSF αT concentration was inversely related to neuritic plaque density (β = -0.21, SE = 0.105, p = 0.04) in regression models adjusted for age, gender, education, and APOE-4. Ventricular CSF αT concentration was positively associated with perceptual speed (β = 0.27, SE = 0.116, p = 0.02) whereas the γT/αT ratio was negatively associated with episodic memory (β = -0.037, SE = 0.017, p = 0.04). Only vCSF αT, but not γT, was correlated with postmortem interval (PMI). Adjustment for PMI had no effect on significance of associations between αT and perceptual speed or γT/αT and episodic memory, but after this adjustment the αT concentration was no longer significantly associated with neuritic plaques. These data suggest that vCSF αT, but not γT, is weakly associated with less Alzheimers disease neuropathology, specifically neuritic plaques, and correlates with better performance on tests of perceptual speed.

Healthy eating index of black and white older adults

Abstract The Healthy Eating Index (HEI) is a measure of dietary quality that was developed to capture the multi-dimensional aspects of eating patterns and to track diet quality over time. We computed HEI scores based on responses to food frequency questionnaires among 4,932 participants in the Chicago Health and Aging Project (CHAP), an ongoing population-based study of adults aged 65 years and older (61% black; 39% white). The average HEI score for the CHAP population was 70.7, below the range of 80–100 defined as a “good” diet by the USDA. Scores varied significantly by race and gender. White women had the highest HEI scores (mean, 73.5;n = 1198) followed by black women (mean, 71.5; n = 1797) and white men (mean, 70.5;n = 744). Black men had the lowest scores (mean, 66.8; n = 1193). Many older urban adults, and in particular, older black men, may have diets that are inadequate according to USDA dietary recommendations.