Abstract
PURPOSE: Adherence to higher-quality diets has been linked to better cognitive function in older adults. Limited research exists on the EAT-Lancet diet, a healthy reference diet aligned with sustainability goals. This study examined the association between adherence to the EAT-Lancet diet and cognitive function and decline in older adults. METHODS: Data from 1,371 participants aged 55–99 years from the Longitudinal Aging Study Amsterdam were analyzed. Adherence to the EAT-Lancet diet was assessed in 2014–2015 using a diet quality index based on a 238-item food frequency questionnaire. Cognitive domains—global cognition (MMSE), information processing speed (Coding task), episodic memory (15-Word Test), and executive function (Word Fluency)—were measured every three years (2011–2021) and converted to z-scores. Linear mixed models assessed associations between quintiles of adherence and cognitive function and decline (testing interaction with age), adjusting for demographic and lifestyle factors. Interaction by sex was tested. RESULTS: Higher adherence to the EAT-Lancet diet was associated with better executive function (Q5 vs. Q1, β = 0.19 (0.07;0.30), P-trend 0.002), but not with episodic memory, information processing speed or global cognition. Higher adherence was associated with slower decline in information processing speed (Q5, Q3 vs. Q1, β = 0.01 (0.00;0.02), P trend 0.005), with no associations for other domains. CONCLUSION: Higher adherence to the EAT-Lancet diet is associated with better executive function and slower decline in information processing speed in Dutch older adults. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00394-025-03753-3.