The relationship between cardiovascular health and brain aging is complex, with various mechanisms at play. Maintaining physical fitness throughout life can benefit both the heart and the brain, while sedentary lifestyles may lead to cognitive decline in old age. The Heart-Brain Axis connects cardiovascular disease (CVD) and Alzheimer’s disease (AD), sharing common risk factors and pathophysiological processes. Atherosclerosis and arteriosclerosis contribute to cognitive impairment through effects on microvascular perfusion and neurovascular function. Understanding these connections may help in developing interventions to prevent dementia.