Dementia, a severe form of cognitive impairment, is characterised by a substantial decline in cognitive function. Stroke is a major risk factor that can accelerate the process of cognitive decline towards dementia (1). Diet stands out among the modifiable factors affecting both cognitive impairment and stroke. Nuts, a common aspect of healthy dietary patterns, provide a balanced fatty acid composition, and are rich in trace elements and bioactive compounds that can benefit vascular health and cognition (2,3). This study aimed to examine the relationship between nut intake and cognitive function and markers of brain health in both stroke and stroke-free populations. Participants from the Framingham Heart Study Offspring cohort were included if they had at least two valid food frequency questionnaires (FFQs) at the baseline period, along with cognitive test results. Participants with diagnosed dementia, traumatic brain injury, brain tumours, or other neurological disorders were excluded from the study. Global cognitive function was calculated as a composite score from the Trail Making Test B, Wechsler Memory Scale (Visual Reproductions and Logical Memory), and the Wechsler Adult Intelligence Scale (Similarities). The cross-sectional relationships between the usual nut intake (average of available FFQs) and measures of global cognitive function, brain volume, and serum brain-derived neurotrophic factor and vascular endothelial growth factor (VEGF) were examined using linear regression models adjusted for demographic, lifestyle, and health-related covariates. The 10-year risk of stroke and dementia was also compared across tertiles of daily nut intake using the Fine-Grey model. A total of 1771 participants were included, comprising 29 with a history of stroke. Nut intake was not associated with any of the outcomes in the stroke-free population. However, the interaction analysis revealed that nut intake was associated with higher global cognitive function in individuals in the lowest quartile of diet quality (β: 0.009; 95% CI: 0.004, 0.014) and physical activity (β: 0.006; 95% CI: 0.000, 0.012). Additionally, nut consumption was associated with increased brain volume in the highest quartile of the physically active population (β: 0.035; 95% CI: 0.003, 0.067). Among the stroke population, nut intake was related to serum VEGF (β: 9.779; 95% CI: 2.013, 17.543), a pattern also observed in the lowest quartile of physical activity among the stroke-free population (β: 2.192; 95% CI: 0.119, 4.262). The risk of stroke and dementia incidence was similar across tertiles of nut consumption after a decade of follow-up. The results indicate that nut intake may benefit cognition and brain health in individuals with an unhealthy lifestyle. The small sample size of the stroke population resulted in an underpowered analysis, potentially limiting the ability to elucidate the true relationship between nut intake and cognition-related outcomes. This highlights the need for studies with larger sample sizes of stroke survivors.