Do angiotensin receptor blockers protect against Alzheimer's disease?

Because growing evidence suggests that angiotensin II receptor blockers (ARBs) effectively inhibit oxidative stress, amyloid beta protein (Aβ) metabolism, and tau phosphorylation in animal brains, ARBs are considered to be a potential candidate for the treatment of Alzheimer's disease (AD). Consistent with such basic studies, two recent observational studies and a small prospective, randomized, open-label trial have shown the effectiveness of ARBs in preventing AD and/or slowing its progression. Nonetheless, large clinical trials have not shown their effectiveness, but their results are debatable because of short follow-up durations and heterogeneity of the cognition assessments used in the studies. Because a recent analysis of the Honolulu-Asia Aging study showed that abnormalities of the serum Aβ level begin approximately 15 years before the diagnosis of AD, long-term clinical trials assessing dementia as a primary endpoint with sensitive measurements of cognition and brain imaging techniques will clarify the effectiveness of ARBs in AD treatment.