Cardiovascular disease (CVD) is the leading cause of death and disability in the United States, affecting more than 81 million American adults. It is well established that risk factors such as hypertension, diabetes, and hyperlipidemia not only place individuals at risk for CVD, but also place them at risk for neurocognitive impairment and dementia. CVD risk factors have been shown to be associated with a cascade of neurophysiologic and neuroanatomic changes, resulting in cognitive impairment and dementia. Exercise and diet have been shown to improve CVD risk factors and also appear particularly promising lifestyle approaches for preventing dementia among individuals at risk, such as those with cognitive impairment, no dementia (CIND). ENLIGHTEN is a randomized clinical trial of diet and exercise among patients with CIND.