Association of Habitual Diet Quality and Nutrient Intake with Cognitive Performance in Community-Dwelling Older Adults: A Cross-Sectional Study.

Objectives: The rapid aging of the U.S. population has raised concerns about age-related cognitive decline and Alzheimer's disease. Therefore, we aimed to characterize diet quality, nutrient intake, and to examine the associations between specific dietary components and cognitive performance in older adults. Design: Cross-sectional observational study. Setting: Community-based recruitment. Participants: Data from 72 community-dwelling adults aged 65 years and older was analyzed. Measurements: Cognitive performance was assessed using subtests from the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) battery, evaluating episodic memory (Word List Memory/Recall/Recognition), visuospatial skills (Constructional Praxis), and executive function (Verbal Fluency). A composite cognitive score was calculated from memory and visuospatial subtests. Habitual dietary intake was evaluated using structured 24-h recalls to calculate nutrient intake and the Healthy Eating Index score, supplemented by the Short HEI questionnaire. Demographics, health history, depressive symptoms (Patient Health Questionnaire-9), and sleep quality (Pittsburgh Sleep Quality Index) were also collected. Results: Participants demonstrated suboptimal diet quality (mean HEI score 62.9 ± 10.69; recommended >80), with only 9.7% meeting fiber recommendations, 11% meeting calcium or vitamin A recommendations, and 1.4% meeting vitamin D requirements. In bivariate comparisons, higher cognitive performance was observed in younger participants (75.5 vs. 79.5 years; p < 0.01) and females (78% vs. 50%; p = 0.024). Regression models identified significant positive associations between cognitive scores and intakes of dietary fiber (p = 0.007), unsaturated fats (mono- and polyunsaturated; p = 0.012-0.033), protein (p = 0.018), carotenoids (α-carotene, p = 0.001; β-carotene, p = 0.026; lutein + zeaxanthin, p = 0.016), vitamins A (p = 0.044) and E (p = 0.034), and minerals including magnesium (p = 0.006), potassium (p = 0.004), copper (p = 0.008), zinc (p = 0.024), and calcium (p = 0.035). Refined grain intake was inversely associated with cognition (p = 0.011). Conclusions: In this population, dietary components like fiber and micronutrients were positively associated with better cognitive function, and the overall nutrient intake shortfalls observed highlight the need for targeted dietary interventions to support healthy brain aging. Therefore, this work advances our understanding by highlighting potential modifiable nutritional targets for clinical trials focused on delaying or preventing cognitive decline.