BackgroundLittle information is yet available for the association between daily water intake, a modifiable lifestyle factor, and Alzheimer's disease (AD) pathology and cerebrovascular injury in the living human brain.ObjectiveOur aim was to explore the correlation between daily fluid intake and in vivo AD pathologies (i.e., amyloid-β (Aβ) and tau) and cerebrovascular injury.Methods287 cognitively normal (CN) older adults completed extensive clinical assessments, daily fluid intake evaluations, and multimodal brain imaging at both the initial baseline and the subsequent 2-year follow-up.ResultsLow daily fluid intake was significantly associated with a higher level or a more rapid increase of Aβ deposition, especially in apolipoprotein E4 negative individuals. Meanwhile, low daily fluid intake was cross-sectionally related with cerebrovascular injury.ConclusionsOur findings suggest that high daily fluid intake is associated with decreased brain amyloid deposition, indicating that sufficient daily fluid intake may be helpful for prevention of AD.