Clinical Testing of Alkaline Water for Digestive Health

Medical research conducted in Japan shows that alkaline water is not medicine, but it can have a positive effect on digestive health. Japanese doctors routinely prescribe daily consumption of alkaline ionized water for mild cases of digestive upset.

Clinical research also proves that skeptics of alkaline water are wrong; the stomach does not completely neutralize the pH of alkaline water!

Alkaline Water’s Antacid Effect

Research done by the 2nd Internal Medicine Dept. of Shiga Medical University and Dept. of Gastroenterology, National Ohkura Hospital, Japan tested alkaline water’s ability to act as an antacid by measuring the pH of the stomachs of 6 volunteers before and after drinking alkaline water.

In the study, 6 volunteers were given alkaline ionized water at pH levels of 9, 10, and 11 and told to drink 1 liter per day. Stomach pH levels were measured inside the volunteer’s stomachs for a period of 24 hours, and researchers verified an increase in pH inside the volunteer’s stomachs from drinking alkaline ionized water at a pH of 9 or greater.

Based on the graph provided, alkaline water increased stomach alkalinity in all 6 volunteers by .5 pH to almost 1 pH. Keep in mind an increase of 1 pH is a 10-fold increase in alkalinity! Researchers concluded that alkaline water demonstrates a mild antacid effect. What is most notable about the study results is that stomach pH rose in all cases, demonstrating clearly that alkaline water’s pH is not completely neutralized by stomach acid.

Effects of Alkaline Water on Gastrointestinal Symptoms

The impact of alkaline water on common digestive problems such as chronic diarrhea, constipation, abnormal fermentation in intestines, indigestion, acid indigestion, and other complaints was evaluated using 25 volunteer subjects.

The patients were given alkaline ionized water with a pH level of 9.5 to drink for 2 weeks. The test subjects were interviewed after two weeks to find out if there was any effect on their symptoms. Researchers noted improvement in 88% of the 25 patients.  The study results revealed that that no patient’s symptoms got worse during the evaluation, and 12% reported no improvement in their condition.

Double-Blind Clinical Trial of Alkaline Water

For a more objective evaluation, a “double-blind comparison clinical test” was carried out. Keep in mind that double blind testing is considered the “gold standard” for proof in the medical community! Patients were selected that had gastrointestinal complaints, and divided into two groups. The first group was given alkaline ionized water to drink. The second (control) group was given purified water to drink. The patients drank water and researchers monitored their symptoms for 4 weeks.

At the end of the 4 week period, the patients were interviewed and their symptoms were rechecked. The results of the study revealed that alkaline ionized water was effective for relief of symptoms in the stomach and intestines. Researchers noted that the most significant improvements were noted in relatively mild cases. The study confirmed effectiveness of alkaline water to relieve symptoms in mild cases of chronic diarrhea and constipation.

The patient’s stools were also evaluated and researchers found that there were improvements in stool quality for patients with stool abnormalities.

Alkaline Water vs. Control Group


Chart Alkaline water relief from upset stomach

These clinical tests indicated that alkaline ionized water may help improve the health of the stomach and intestines in mild cases.

The research also confirms that unlike medicine, there’s no promise of an immediate effect.

Talk to your doctor about alkaline water

Daily consumption of alkaline water as it may lead to gentle and gradual improvements in cases of digestive upset, but talk to your doctor before starting to drink alkaline water.

Alkaline ionized water should be consumed on an empty stomach, and users should keep in mind that alkaline ionized water is not always effective for all stomach and intestinal problems.

 To find out more about the effect of alkaline water on the the stomach, call us at: (888) 688-8889

Has the FDA evaluated the safety or effectiveness of alkaline water?

No. These statements have not been evaluated by the Food and Drug Administration.  The preceding information and/or products are for educational purposes only and are not meant to diagnose, prescribe, or treat illness. Please consult your doctor before making any changes or before starting ANY exercise or nutritional supplement program or before using this information or any product during pregnancy or if you have a serious medical condition.


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[Tashiro, et al: “Digestion and Absorption” issued by the Japan Digestion and Absorption Academics Society Vol. 23 No. 2, pp. 52-56 (2000)]
[Tashiro: P473-477, 5th Revision of the 32nd Edition of “Digestive Organs” published by Kagaku Hyoron Sha (2001)]
[Kitahora: Journal (T) of the 26th General Assembly of the Medical Congress of Japan (p. 33) (2003)]
[Itokawa: FOOD Style 21, Vol. 7, No. 8, pp. 81–83 (2003)]