Influence of dietary patterns on cognitive decline and neurodegenerative processes among older adults

Background Cognitive decline and neurodegenerative diseases are growing public health issues, especially in aging populations. This study observed how dietary patterns are associated with cognitive performance and neurodegenerative biomarkers among older adults in aging populations.Methods A retrospective study of 500 adults aged ≥65 years in Lahore examined associations between dietary patterns, cognitive outcomes, and neurodegenerative biomarkers, with participants classified into Mediterranean or non-Mediterranean (Western, plant-based, or mixed) dietary groups based on FFQ- and 24-hour recall–derived pattern scores, alongside standardized cognitive assessments and clinical neuroimaging measures.Results Mediterranean and plant-based diets were associated with improved cognitive performance and lower levels of neurodegenerative biomarkers compared to Western diets. Adherence to a Mediterranean diet was associated with reduced MMSE decline (β = 0.37, 95% CI: 0.18–0.56, p < 0.001), higher MoCA scores (β = 1.20, 95% CI: 0.75–1.65, p < 0.001), and improved memory and executive function (β = 0.31, 95% CI: 0.12–0.50, p = 0.002). Diets based on plants were associated with cognitive outcomes. Neuroimaging showed associations with increased hippocampal volume (β = 0.42–0.48, p < 0.001), FDG-PET metabolism (β = 0.07–0.09, p ≤ 0.001), and associations with decreased WMH volume (β = −0.35 to 0.41, p ≤ 0.005). Plant-based and Mediterranean diets were associated with reduced neurofilament light levels. Mixed/other diets showed moderate associations.Conclusion Mediterranean and plant-based diets are associated with more favorable neuroimaging profiles, neurodegenerative biomarkers, and elderly cognition, while Western diets are associated with neurodegeneration and cognitive loss.