Drink at Least 8 Glasses of Water a Day to Be Healthy???

Clark, William F. MD, FRCPC, FACP, FASN, FCAHS; Huang, Shih-Han Susan MD, FRCPC; Garg, Amit X. MD, FRCPC, FACP, PhD; House, Andrew MD, MSc, FRCPC, FASN; Moist, Louise M. MSc, MD, FRCPC; Weir, Matthew MD, MSc, FRCPC; Sontrop, Jessica M. PhD

Nutrition Today:
doi: 10.1097/NT.0b013e3182978668
Feature Article
Abstract

The saying “drink at least 8 glasses of water per day to be healthy” has had little supporting evidence. The purpose of this article was to briefly introduce the role of hydration in health in order to explore in more detail recent observational studies of hyperhydration in chronic kidney disease (CKD) in man. The Modification of Diet in Renal Disease study initially noted a negative association between increasing urine output and progression of CKD that was absent when corrected for baseline variables. Recently, data from 2 different cross-sectional populations found those with the highest fluid intake had a significantly lower risk of CKD. In a longitudinal, community-based cohort study adjusted for baseline variables, decline in kidney function was significantly slower in those with higher versus lower baseline urine volume. These new and contradictoryresults underline the need for a randomized controlled study to test the hypothesis that increased fluid intake will slow renal decline.

Author Information

William F. Clark, MD, FRCPC, FACP, FASN, FCAHS, is a professor of medicine at Western University; Victoria Hospital–London Health Sciences Centre, Ontario, Canada.

Shih-Han Susan Huang, MD, FRCPC, is a lecturer at Western University; Victoria Hospital–London Health Sciences Centre, Ontario, Canada.

Amit X. Garg, MD, FRCPC, FACP, PhD, is a professor of medicine at Western University; Victoria Hospital–London Health Sciences Centre, Ontario, Canada.

Andrew House, MD, MSc, FRCPC, FASN, is an associate professor of medicine at Western University; London Health Sciences Centre, University Hospital, Ontario, Canada.

Louise M. Moist, MSc, MD, FRCPC, is a professor of medicine at Western University, Victoria Hospital–London Health Sciences Centre, Ontario, Canada.

Matthew Weir, MD, MSc, FRCPC, is an assistant professor of medicine at Western University; London Health Sciences Centre, University Hospital, Ontario, Canada.

Jessica M. Sontrop, PhD, is an assistant professor at Department of Epidemiology & Biostatistics, Western University, London; and Victoria Hospital–London Health Sciences Centre, Ontario, Canada.

Source of support: Canadian Institutes of Health Research, Kidney Foundation of Canada, Ontario Ministry of Health, Danone Industries, Western University Canada.

The authors have no conflicts of interest to disclose.

Correspondence: William F. Clark, MD, FRCPC, FACP, FASN, FCAHS, Victoria Hospital–London Health Sciences Centre, 800 Commissioners Rd E, A2-343, London, ON, Canada N6A 5W9 (william.clark@lhsc.on.ca).

© 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins