The incidence of dementia and cardiovascular disease (CVD) increases with age. Current evidence supports the role for both atherosclerosis and arteriosclerosis as a common pathophysiological ground for the heart-brain connection in ageing. Cognitive decline and CVDs share many vascular risk factors (VRFs) such as smoking, hypertension, and diabetes mellitus; furthermore, CVDs can contribute to cognitive decline by causing cerebral hypoperfusion, hypoxia, emboli, or infarcts. Mixed dementia, resulting from both cerebrovascular lesions and neurodegeneration, accounts for the majority of dementia cases among very old individuals (≥75 years). An accumulation of multiple VRFs, especially in middle age (40-59 years of age), can substantially increase dementia risk. The suggested declining trend in dementia risk, occurring in parallel with the decreasing incidence of cardiovascular events in high-income countries, supports the role of cardiovascular burden in dementia. Accordingly, strategies to promote cardiovascular health, especially if implemented from early life, might help to delay the onset of dementia. In this Review, we discuss the literature investigating the association of cardiovascular burden with cognitive decline and dementia over the life-course.