{{Short description|Pseudoscientific home appliance}} 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.<ref name="Aoki_1994" /><ref name=":1">{{Cite journal| vauthors = Henry M, Chambron J |date= December 2013 |title=Physico-Chemical, Biological and Therapeutic Characteristics of Electrolyzed Reduced Alkaline Water (ERAW)|journal= Water |volume=5|issue=4|pages=2094–115|doi=10.3390/w5042094|doi-access=free}}</ref><ref name=":0" /> 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 principles of chemistry and physiology.<ref name=":3">{{Cite web |title=Alkaline Water Nonsense |url=https://www.mcgill.ca/oss/article/controversial-science-news-quackery/alkaline-water-nonsense | date= 20 March 2017 | first= Joe| last= Schwarcz |website= mcgill.ca| publisher= Office for Science and Society, McGill University |language=en |access-date=2025-07-29}}</ref> There is no medical evidence for any health benefits of alkaline water. Extensive scientific evidence has debunked these claims,<ref>{{cite journal | vauthors = Heaney RP, Layman DK | title = Amount and type of protein influences bone health | journal = The American Journal of Clinical Nutrition | volume = 87 | issue = 5 | pages = 1567S–1570S | date = May 2008 | pmid = 18469289 | doi = 10.1093/ajcn/87.5.1567s | doi-access = free }}</ref><ref name= "Systematic BMJ">{{Cite journal |last1=Fenton |first1=Tanis R. |last2=Huang |first2=Tian |date=June 2016 |title=Systematic review of the association between dietary acid load, alkaline water and cancer |journal=BMJ Open |volume=6 |issue=6 |article-number=e010438 |doi=10.1136/bmjopen-2015-010438 |pmc=4916623 |pmid=27297008 |doi-access=free}}</ref><ref name=":3" /> leaving such claims in the pseudoscientific realm.<ref name=":3" />
The machines originally became popular in Japan and other East Asian nations before becoming available in the US and Europe.
==Health claims== Water ionizers are marketed on the basis of health claims which are focused on their ability to make water more alkaline. A wide variety of benefits have been claimed, including the ability to slow aging,<ref name="latimes">{{cite news | work = Los Angeles Times | vauthors = Woolston C | date = 2007-01-22 | title = The Healthy Skeptic; It'll quench your thirst, of course; But whether ionized water can slow aging and fight disease is another matter | url = https://pqasb.pqarchiver.com/latimes/access/1198845891.html?dids=1198845891:1198845891&FMT=ABS&FMTS=ABS:FT&date=Jan+22%2C+2007&author=Chris+Woolston| archive-url = https://web.archive.org/web/20090506223046/http://pqasb.pqarchiver.com/latimes/access/1198845891.html?dids=1198845891:1198845891&FMT=ABS&FMTS=ABS:FT&date=Jan+22%2C+2007&author=Chris+Woolston| archive-date = May 6, 2009 |access-date = 2008-10-30}}</ref> prevent disease, give the body more energy, and offset alleged effects of acidic foods.<ref name=":0">{{Cite news |last=Johannes |first=Laura |date=2012-04-09 |title= The Positives and Negatives of Ionized Water |newspaper=The Wall Street Journal |url= https://www.wsj.com/articles/SB10001424052702303404704577314182468322256 |url-status=live |access-date=2016-05-17 |archive-url= https://archive.today/20170527050618/https://www.wsj.com/articles/SB10001424052702303404704577314182468322256 |archive-date=2017-05-27}}</ref><ref>{{Cite web |last=Torrens |first=Kerry |title=What is the alkaline diet? |url=https://www.bbcgoodfood.com/howto/guide/what-alkaline-diet |publisher=BBC Good Food |url-status=live |archive-url=https://web.archive.org/web/20220413122011/https://www.bbcgoodfood.com/howto/guide/what-alkaline-diet |archive-date= 2022-04-13 |access-date=2022-05-26}}</ref> Some claims include it being twice as hydrating after exercise.<ref>{{Cite web |title=Alkaline Water: Miracle or Marketing? |website= arthritis.org |language=en |publisher= Arthritis Foundation |url=https://www.arthritis.org/health-wellness/healthy-living/nutrition/alkaline-water-benefits |access-date=2024-08-24}}</ref>
There is no empirical evidence to support these claims, nor the claims that drinking ionized water will have a noticeable effect on the body.<ref name= Skeptoid>{{Skeptoid|id=4139|number=139 |title = Alkaline Water Systems: Change Your Water, Change Your Bank Balance |date=February 3, 2009 | name-list-style = vanc |access-date=3 February 2009}}</ref> Drinking ionized water or alkaline water does not alter the body's pH due to acid-base homeostasis.<ref name="latimes"/> 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".<ref>{{Cite journal |last1=Ceponkus |first1=Justinas |last2= Engdahl |first2=Anders |last3=Uvdal |first3=Per |last4=Nelander |first4=Bengt |date=August 2013 |title=Structure and dynamics of small water clusters, trapped in inert matrices |journal=Chemical Physics Letters |volume=581 |pages=1–9 |doi= 10.1016/j.cplett.2013.06.046| bibcode= 2013CPL...581....1C }}</ref>
Some proponents of alkaline water and the alkaline diet as a whole claim a link between alkaline intake and cancer prevention;<ref name= "Systematic BMJ" /> no scientific evidence exists for such a connection,<ref name= "Systematic BMJ" /><ref>{{Cite journal |last1=Zick |first1=Suzanna Maria |last2= Snyder |first2=Detrick |last3=Abrams |first3=Donald I. |date=November 2018 |title=Pros and Cons of Dietary Strategies Popular Among Cancer Patients |journal= Oncology |volume=32 |issue=11 |pages=542–547 |pmid=30474102}}</ref><ref>{{Cite web |date=2021-09-29 |title=Cancer Diets: Myths and More |url= https://www.bda.uk.com/resource/cancer-diets-myths-and-more.html |website= bda.uk.com |publisher=British Dietetic Association |url-status=live |archive-url= https://web.archive.org/web/20211012162819/https://www.bda.uk.com/resource/cancer-diets-myths-and-more.html |archive-date=2021-10-12 |access-date=2022-05-26}}</ref> and as such, several cancer societies have denounced this claim.<ref>{{Cite web |title=Is an alkaline diet better for me? | website= cancer.ca |url=https://cancer.ca/en/cancer-information/reduce-your-risk/myths-and-controversies/is-an-alkaline-diet-better-for-me |publisher=Canadian Cancer Society |url-status=live |archive-url=https://web.archive.org/web/20220121050028/https://cancer.ca/en/cancer-information/reduce-your-risk/myths-and-controversies/is-an-alkaline-diet-better-for-me |archive-date=2022-01-21 |access-date=2022-05-24}}</ref><ref>{{Cite web |date=2010-07-08 |title=The Alkaline Diet: Another Cancer and Diet Claim |url=https://www.aicr.org/resources/blog/another-cancer-and-diet-claim-the-alkaline-diet/| website= aicr.org |publisher=American Institute for Cancer Research |url-status=live |archive-url= https://web.archive.org/web/20220424064329/https://www.aicr.org/resources/blog/another-cancer-and-diet-claim-the-alkaline-diet/ |archive-date=2022-04-24 |access-date=2022-05-24}}</ref><ref>{{Cite web |last=Axelrod |first=Alexandra |date=2018-01-26 |title=Friday Fix: The Alkaline Diet |url= https://www.pancan.org/news/friday-fix-alkaline-diet/ | website= pancan.org |publisher=Pancreatic Cancer Action Network |url-status=live |archive-url= https://web.archive.org/web/20210725131325/https://www.pancan.org/news/friday-fix-alkaline-diet/ |archive-date=2021-07-25 |access-date=2022-05-24}}</ref><ref>{{Cite web |title=Alternative cancer diets |url=https://www.cancerresearchuk.org/about-cancer/coping/physically/diet-problems/managing/alternative-cancer-diets| website= cancerreasearchuk.org |publisher=Cancer Research UK |url-status=live |archive-url= https://web.archive.org/web/20210518151104/https://www.cancerresearchuk.org/about-cancer/coping/physically/diet-problems/managing/alternative-cancer-diets |archive-date=2021-05-18 |access-date=2022-05-24}}</ref>
==Operation== Despite being described as ''water ionizers'', the machines are designed to work as water electrolyzers.<ref name=":0" /> This is an electrochemical process in which water is split to form hydrogen and oxygen by an electric current.<ref name="Aoki_1994">{{cite journal | vauthors = Aoki H, Nakamori M, Aoto N, Ikawa E | title = Wafer treatment using electrolysis-ionized water. | journal = Japanese Journal of Applied Physics | date = October 1994 | volume = 33 | issue = 10R | pages = 5686–5689 | doi = 10.1143/JJAP.33.5686 | bibcode = 1994JaJAP..33.5686A | s2cid = 96980727 }}</ref> In some machines, the process produces calcium hydroxide and hydrochloric acid through the use of an ion-exchange membrane.<ref>{{Cite web |title= Structure and types of alkaline ionized water apparatus |website= 3aaa.gr.jp |publisher= Association of Alkaline Ionized Water Apparatus |url= https://www.3aaa.gr.jp/english/structure.html |access-date=2023-10-31}}</ref>
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.<ref>{{Cite web |date=2018-05-14|first= Alison |last= Campbell |title=Bold claims of water machine examined |website=The New Zealand Herald |language=en-NZ| publisher= |url= https://www.nzherald.co.nz/whanganui-chronicle/news/dr-alison-campbell-bold-claims-of-water-machine-examined/4XZL5V422A3L7W737X6RF2ESBE/ |access-date=2023-10-25}}</ref> 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.<ref name="Aoki_1994" />
== See also == {{Portal|Water}} * Alkaline diet * Pseudoscience * Quackery * Electrodeionization * Magnetic water treatment * Negative air ionization therapy * Self-ionization of water * Ultrafiltration
== References == {{Reflist}}
== External links == * {{cite news | title = Does Your Water Need More Ions? The latest health fad is even more ridiculous than most health fads | first = Kent| last= Sepkowitz | work = Slate | url = http://www.slate.com/articles/technology/technology/2013/03/ionized_and_alkalinized_water_ridiculous_health_fad_debunked.html | access-date = July 19, 2018}}
{{DEFAULTSORT:Water Ionizer}} Category:Alternative medical treatments Category:Drinking water Category:Fad diets Category:Pseudoscience