Jump to content

Water ionizer

From Wikipedia, the free encyclopedia

A water ionizer (also known as an alkaline ionizer) is a home appliance which claims to raise the pH of drinking water by using electrolysis to separate the incoming water stream into acidic and alkaline components.[1][2][3] The treated water is called alkaline water. Proponents claim that consumption of alkaline water results in a variety of health benefits, making it similar to the alternative health practice of alkaline diets. Such claims violate basic principles of chemistry and physiology. There is no medical evidence for any health benefits of alkaline water. Extensive scientific evidence has completely debunked these claims.[4][5]

The machines originally became popular in Japan and other East Asian countries before becoming available in the U.S. and Europe.

Health claims[edit]

Water ionizers are often marketed on the basis of health claims which are normally focused on their putative ability to make water more alkaline. A wide variety of benefits have been claimed, including the ability to slow aging,[6] prevent disease, give the body more energy, and offset alleged effects of acidic foods.[3][7]

There is no empirical evidence to support these claims, nor the claims that drinking ionized water will have a noticeable effect on the body.[8] Drinking ionized water or alkaline water does not alter the body's pH due to acid-base homeostasis.[6] Additionally, marketers have inaccurately claimed that the process of electrolysis changes the structure of water from large non-bioavailable water clusters to small bioavailable water clusters, called "micro clusters".[9]

Some proponents of alkaline water and the alkaline diet as a whole claim a link between alkaline intake and cancer prevention;[5] no scientific evidence exists for such a connection,[5][10][11] and as such, several cancer societies have denounced this claim.[12][13][14][15]


Despite being described as 'water ionizers', the machines are designed to work as water electrolyzers.[3] This is an electrochemical process in which water is split to form hydrogen and oxygen by an electric current.[1][16] In some machines, the process produces calcium hydroxide and hydrochloric acid through the use of an ion-exchange membrane.[17]

The effectiveness of the process is debatable because electrolysis requires significant amounts of time and power; hence, the amount of hydroxide that could be generated in a fast-moving stream of water such as a running tap would be minimal at best.[18][unreliable source] Additionally, the process of reversing the reaction requires much less energy, so if the area between the alkaline and acidic water is at least semi-permeable, the water will undergo another reaction that just leaves neutral water.[1]

See also[edit]


  1. ^ a b c Aoki H, Nakamori M, Aoto N, Ikawa E (October 1994). "Wafer treatment using electrolysis-ionized water". Japanese Journal of Applied Physics. 33 (10R): 5686–5689. Bibcode:1994JaJAP..33.5686A. doi:10.1143/JJAP.33.5686. S2CID 96980727.
  2. ^ Henry M, Chambron J (December 2013). "Physico-Chemical, Biological and Therapeutic Characteristics of Electrolyzed Reduced Alkaline Water (ERAW)". Water. 5 (4): 2094–115. doi:10.3390/w5042094.
  3. ^ a b c Johannes, Laura (2012-04-09). "The Positives and Negatives of Ionized Water". The Wall Street Journal. Archived from the original on 2017-05-27. Retrieved 2016-05-17.
  4. ^ Heaney RP, Layman DK (May 2008). "Amount and type of protein influences bone health". The American Journal of Clinical Nutrition. 87 (5): 1567S–1570S. doi:10.1093/ajcn/87.5.1567s. PMID 18469289.
  5. ^ a b c Fenton, Tanis R.; Huang, Tian (June 2016). "Systematic review of the association between dietary acid load, alkaline water and cancer". BMJ Open. 6 (6): e010438. doi:10.1136/bmjopen-2015-010438. PMC 4916623. PMID 27297008.
  6. ^ a b Woolston C (2007-01-22). "The Healthy Skeptic; It'll quench your thirst, of course; But whether ionized water can slow aging and fight disease is another matter". Los Angeles Times. Retrieved 2008-10-30.
  7. ^ Torrens, Kerry. "What is the alkaline diet?". BBC Good Food. Archived from the original on 2022-04-13. Retrieved 2022-05-26.
  8. ^ Dunning B (February 3, 2009). "Skeptoid #139: Alkaline Water Systems: Change Your Water, Change Your Bank Balance". Skeptoid. Retrieved 3 February 2009.
  9. ^ Ceponkus, Justinas; Engdahl, Anders; Uvdal, Per; Nelander, Bengt (August 2013). "Structure and dynamics of small water clusters, trapped in inert matrices". Chemical Physics Letters. 581: 1–9. Bibcode:2013CPL...581....1C. doi:10.1016/j.cplett.2013.06.046.
  10. ^ Zick, Suzanna Maria; Snyder, Detrick; Abrams, Donald I. (November 2018). "Pros and Cons of Dietary Strategies Popular Among Cancer Patients". Oncology. 32 (11): 542–547. PMID 30474102.
  11. ^ "Cancer Diets: Myths and More". British Dietetic Association. 2021-09-29. Archived from the original on 2021-10-12. Retrieved 2022-05-26.
  12. ^ "Is an alkaline diet better for me?". Canadian Cancer Society. Archived from the original on 2022-01-21. Retrieved 2022-05-24.
  13. ^ "The Alkaline Diet: Another Cancer and Diet Claim". American Institute for Cancer Research. 2010-07-08. Archived from the original on 2022-04-24. Retrieved 2022-05-24.
  14. ^ Axelrod, Alexandra (2018-01-26). "Friday Fix: The Alkaline Diet". Pancreatic Cancer Action Network. Archived from the original on 2021-07-25. Retrieved 2022-05-24.
  15. ^ "Alternative cancer diets". Cancer Research UK. Archived from the original on 2021-05-18. Retrieved 2022-05-24.
  16. ^ Shermer M (2002-01-01). The Skeptic Encyclopedia of Pseudoscience. Vol. One. ABC-CLIO. p. 130. ISBN 9781576076538.
  17. ^ "Association of Alkaline Ionized Water Apparatus|Structure and types of alkaline ionized water apparatus". www.3aaa.gr.jp. Retrieved 2023-10-31.
  18. ^ Campbell, Alison (2018-05-14). "Bold claims of water machine examined". NZ Herald. Retrieved 2023-10-25.

External links[edit]