Adhering to Healthy Dietary Patterns Prevents Cognitive Decline of Older Adults with Sarcopenia: The Mr. OS and Ms. OS Study

<b>Background</b>: The progression of cognitive decline is accelerated in older adults with sarcopenia, but the protective dietary factors have remained uncertain. <b>Objective</b>: This study aims to investigate the association between dietary factors and cognitive decline in older adults, and to explore the potential mediating effects of sarcopenic components. <b>Methods</b>: Data from the Mr. OS and Ms. OS cohort study in Hong Kong (<i>N</i> = 3146, aged ≥65 years) were used. Cognitive function was assessed based on the Mini-Mental State Examination (MMSE). Sarcopenic status was assessed according to the Asian Working Group for Sarcopenia 2019 updated consensus. Dietary protein intake and adherence to dietary patterns were assessed using a food frequency questionnaire. Linear regression was used to examine the associations between dietary factors and MMSE scores. Mediation analysis was conducted to identify the possible mediators in the diet-cognition associations. <b>Results</b>: Sarcopenia and its components were associated with baseline MMSE and MMSE changes. Positive associations were observed for plant protein intake (β = 0.79, 95% CI 0.24-1.35) and dietary patterns such as the Dietary Approaches to Stop Hypertension (DASH) diet (β = 0.14, 95% CI 0.02-0.26) and diets with lower Dietary Inflammatory Index (DII) scores (β = -0.18, 95% CI -0.26--0.09) with better MMSE outcomes. Protective effects were more profound in participants with sarcopenia/severe sarcopenia. The effects of the DASH diet and DII were more profound in female participants, while higher adherence to the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet was associated with an increment in MMSE score in male participants with sarcopenia. Handgrip strength and physical performance are significant mediators in the diet-cognition associations. <b>Conclusions</b>: The protective effects of healthy dietary patterns were beneficial, especially for participants with sarcopenia, while handgrip strength and walking speed potentially mediated the associations.