Hydrogen Water Improves Sleep and Digestive Health in Healthy Adults
Daily ingestion of alkaline electrolyzed water containing hydrogen influences human health, including gastrointestinal symptoms
- Evidence type
- Randomized controlled trial · Human study
- Authors
- Yoshinori Tanaka, Yasuhiro Saihara, Kyoko Izumotani, Hajime Nakamura
- Journal
- Medical Gas Research
- Year
- 2019
- PMID
- 30713669
- Study Type
- Human
- Participants
- 60
- Delivery
- Water (Electrolysis)
- Dose
- Daily ingestion of alkaline electrolyzed water for 4 weeks
- Duration
- 4 weeks
- Funding
- Matsushita Electric Works Co., Ltd. Home Appliances R&D Center
- Conflicts of interest
- The corresponding author (YT) is a salaried employee of the Panasonic Corporation. One of the authors (SY) was a salaried employee of the Panasonic Corporation.
- Outcome
- Positive
- Peer Reviewed
- Yes
- Cited by
- 36 (OpenAlex, as of November 2026)
- Country
- Japan
TL;DR
Drinking alkaline electrolyzed water (AEW) daily may improve stool regularity and sleep quality, even in people without stomach complaints.
Key Finding
Healthy people without baseline gastrointestinal complaints who drank alkaline electrolyzed water containing hydrogen reported improved stool normalization and better sleep quality compared to those drinking regular water, though overall health effects were modest.
Summary
Researchers gave healthy people without stomach problems either alkaline electrolyzed water (water treated with electricity to add hydrogen) or regular purified water for 4 weeks in a double-blind study (where neither the participants nor researchers knew who got which water). People drinking the hydrogen-containing water reported more normal stools, better sleep quality, and felt better when waking up, possibly because hydrogen may reduce harmful molecules in the body called oxidative stress. However, the overall health improvements were modest and not as clear-cut as in studies of people who already had stomach problems.
Practical Takeaway
This small study suggests hydrogen water may support normal digestion and sleep in healthy people, but the evidence is preliminary and the study did not report sample size or exact duration. Larger, longer studies are needed before drawing firm conclusions about benefits for people without existing health complaints.
Abstract (excerpt)
In Japan, alkaline electrolyzed water (AEW) apparatus have been approved as a medical device. And for the patients with gastrointestinal symptoms, drinking AEW has been found to be effective in relieving gastrointestinal symptoms. But some users of AEW apparatus do not have abdominal indefinite…