One mechanism by which antihypertensives may protect against AD is via Aβ neuropathology. In order to better understand the mechanisms through which ACE-I may modify CSF Aβ and possibly AD risk, we propose a randomized, double-blind, placebo-controlled pilot clinical trial, enrolling 20 middle-aged (age range 40 - 65 years), mildly hypertensive (between 130 - 160 mmHg mean systolic and between 85 - 100 mmHg mean diastolic) participants, who are adult children of an individual with AD. The main objective of this trial is to examine the effects of the ACE-I, ramipril, on 1) CSF Aβ levels 2) CSF ACE levels and 3) peripheral endothelial function as measured by brachial artery flow-mediated vasodilation (FMD) and aortic augmentation index (AAIx), in middle-aged adults with mildly elevated BP, who are at increased risk of developing AD.