Improving DASH adherence after midlife promotes better late-life cognition and brain health: the SG70 Study

Abstract

Healthier dietary patterns reduce cognitive impairment risks, but whether diet improvement after mid-life can benefit cognition and brain health, and how brain measures mediate diet-cognition associations, remain unclear, as few studies had long-term diet records alongside detailed neuroimaging and cognitive measures. We assessed adherence to the Dietary Approaches to Stop Hypertension (DASH) in 892 SG70 participants, nested within the Singapore Chinese Health Study, between 1993-2025. Adherence during midlife (44-55 years) and early elderhood (61-73 years) were related to seven cognitive domains, brain morphometry, white matter hyperintensities (WMH), and free-water markers measured in late life (68-82 years). Higher adherence at both mid-life stages was associated with better verbal memory. Higher mid-life adherence was associated with greater white matter volume in association tracts, whereas higher early-elderhood adherence was associated with lower free water (frontal and occipital) and lower WMH (basal ganglia and anterior periventricular). Moreover, white matter volume and free water mediated the diet-verbal memory associations at their respective midlife stages. Importantly, participants with improved mid-to-late life diet trajectories showed better late-life verbal memory and brain health than those with persistently low adherence. Overall, ensuring mid-life diet quality and improving post-midlife diet may promote cognitive resilience through structural reserve and neurovascular health.