“Alkaline water improves health by correcting the body's acidity.”
Alkaline water does not correct your body's acidity, because your body already keeps blood pH tightly controlled.
You do not need alkaline water to balance your body's pH; your kidneys already do that. If you like the taste, it is fine to drink, but it is not a health upgrade over regular water.
Drink whatever safe water you enjoy, and skip paying extra for alkaline water for health reasons.
Studies that measured both blood and urine show that what you eat or drink can change urine pH but barely moves blood pH, because the body, mainly through the kidneys, keeps blood acidity in a tight range. A review of alkaline water in healthy people found no health benefit over mineral water; confidence is moderate because those studies were few and small.
Alkaline water does not correct your body's acidity, because your body already keeps blood pH tightly controlled. Drinking it can raise urine pH a little, but studies have not found any health benefit from that.
In studies that measured both, changing diet or taking an alkaline salt raised urine pH by up to 1.2 units, while blood pH moved by only 0.01 to 0.02 units. That shows the kidneys clear extra acid or base to keep the blood steady, and that urine pH is not a measure of the body's acidity. A 2024 review of special waters in healthy people found two studies on alkaline water, and neither showed any difference from mineral water in gut bacteria, urine pH, blood tests or fitness. In a 2022 study, 73 young adults drank regular water for a week and then alkaline water for a week, and their average urine pH rose from 5.98 to 6.52; there was no comparison group, and the earlier studies it pooled varied widely. A 2016 review found no human studies supporting alkaline water for preventing or treating cancer.
- Fenton TR, Huang T. Systematic review of the association between dietary acid load, alkaline water and cancer. BMJ Open. 2016;6(6):e010438. DOI: 10.1136/bmjopen-2015-010438. PMID: 27297008. PMCID: PMC4916623
- Sunardi D, Chandra DN, Medise BE, Manikam NRM, Friska D, Lestari W, Insani PNC. Health effects of alkaline, oxygenated, and demineralized water compared to mineral water among healthy population: a systematic review. Reviews on Environmental Health. 2024;39(2):339-349. DOI: 10.1515/reveh-2022-0057. PMID: 36571558
- Zhang G, Deng T, Deng R, Sun X, He Y, Liu Z. Baseline urine pH is related to effective urine alkalization by short-term alkaline water supplementation: data from a self-controlled study in healthy Chinese volunteers following a systematic review and meta-analysis of literature. Translational Andrology and Urology. 2022;11(5):710-719. DOI: 10.21037/tau-22-280. PMID: 35693715. PMCID: PMC9177264