It could also be that a greater volume of water would be needed to demonstrate a protective effect for the kidneys. Despite the coaching efforts of dietitians and research assistants, the mean urine volume increase in the hydration group relative to the control group was just 0.6 liter per day, or 2.4 cups.
“This highlights how difficult it would be to achieve a large sustained increase in water intake in routine practice,” Dr. Clark and colleagues said in their report.
Dr. Clark reported disclosures related to Danone Research. Thermo Fisher Scientific provided instrumentation, assay reagent, and disposables used in the study.
SOURCE: Clark WF et al. JAMA. 2018;319(18):1870-9.