Alkaline water: what the evidence says
Alkaline water is sold with big promises about energy, aging and disease. The evidence behind those promises is thin. Here is what is known, and what to do instead.
What alkaline water is
Alkaline water has a pH above 7, often 8 to 9.5. The pH comes either from dissolved minerals or from treatment such as electrolysis. Ordinary drinking water is usually close to neutral.
What the research shows
Your kidneys and lungs keep blood pH within a very narrow range, and stomach acid neutralizes most of what you drink. For those reasons, drinking alkaline water is not expected to change your blood chemistry in a meaningful way.
A 2016 systematic review in BMJ Open looked for evidence that dietary acid load or alkaline water affects cancer, and found none that it prevents or treats it. Smaller studies have looked at other outcomes, such as reflux and hydration after exercise, with limited or mixed results.
Cost and who should ask first
Plain alkaline water is generally considered low risk for healthy people, but it costs more than tap water. People with kidney disease should ask their physician before changing what they drink or adding mineral supplements.
What helps hydration more
Drink enough to satisfy thirst and replace what you lose in activity and heat. Pale yellow urine is a rough guide. If you are always thirsty, tired or dizzy, ask a clinician, because that can have causes water does not fix.
Staying hydrated matters in every season, and warm fluids are one tip for cold stress. For practical advice that has stronger evidence behind it, see our workplace health tips. For habits that matter more to workplace health, see healthy lifestyle at work.
General information, not medical advice.
References
About the clinical team behind this page
Dr. Arnaldo Manuel Mora is Medical Director and leads clinical governance at Nova. His background is in internal and occupational medicine. He oversees diagnostic intake, baseline laboratory review and the safety standards that apply before any prescription therapy, including pharmacy sourcing and contraindication screening as described in our safety guide.
Dr. Michael D. Schreiber is an osteopathic physician. He applies osteopathic principles to musculoskeletal diagnosis and rehabilitation, looking at the whole kinetic chain when judging how a joint or tendon problem developed, and advises on how physician care and physical therapy fit together. He is a graduate of the Chicago College of Osteopathic Medicine of Midwestern University, class of 1992.
Medical disclaimer: The information on this site is for education and does not replace a consultation, diagnosis or treatment. Full credentials are on our physicians and clinical governance page.
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Individual results vary and no outcome is guaranteed. This page is general information, not medical advice.