Hydrogen Gas Inhalation Improves Memory in Alzheimer's Patients
Therapeutic Inhalation of Hydrogen Gas for Alzheimer's Disease Patients and Subsequent Long-Term Follow-Up as a Disease-Modifying Treatment: An Open Label Pilot Study
Research hubs: Brain & Nervous System
- Evidence type
- Uncontrolled trial (single-arm or pilot) · Human study
- Authors
- Hirohisa Ono, Yoji Nishijima, Shigeo Ohta
- Journal
- Pharmaceuticals
- Year
- 2023
- PMID
- 36986533
- Study Type
- Human
- Participants
- 8
- Delivery
- Gas
- Dose
- 3% H2 gas for one hour twice daily for 6 months
- H₂ concentration
- 3% H2 gas
- Duration
- 6 months
- Funding
- No external funding declared
- Conflicts of interest
- The authors are applicants of a patent resulting from this work. S.O. is the director of H2 WATER JAPAN Inc. and the H2 Global Group, companies involved in H2.
- Outcome
- Positive
- Peer Reviewed
- Yes
- Cited by
- 21 (OpenAlex, as of November 2026)
- Country
- Japan
TL;DR
Inhaling hydrogen gas improved memory and brain health in Alzheimer's patients over a six-month treatment period, with some lasting effects observed up to a year.
Key Finding
Eight Alzheimer's disease patients who inhaled 3% hydrogen gas twice daily for 6 months showed significant cognitive improvement and restored nerve fiber integrity in the hippocampus, with benefits sustained during the 1-year follow-up period.
Summary
This small pilot study followed 8 Alzheimer's disease patients who inhaled 3% hydrogen gas for one hour twice daily for 6 months, then were monitored for another year without the gas. Researchers measured cognitive function using a standard Alzheimer's test and used advanced brain imaging to assess nerve fiber integrity in a memory-related brain region. After 6 months of hydrogen inhalation, patients showed cognitive improvement, while untreated comparison data suggested decline; brain imaging also showed improved nerve fiber structure that was largely maintained during follow-up.
Practical Takeaway
This early-stage pilot study in a very small group suggests hydrogen gas inhalation may warrant further investigation for Alzheimer's disease, but the lack of a control group, small sample size, and open-label design (where participants knew they were receiving treatment) limit what can be concluded. Larger, well-controlled clinical trials would be needed before hydrogen gas could be considered a proven treatment option.
Abstract (excerpt)
(1) Background: Alzheimer's disease (AD) is a progressive and fatal neurodegenerative disorder. Hydrogen gas (H2) is a therapeutic medical gas with multiple functions such as anti-oxidant, anti-inflammation, anti-cell death, and the stimulation of energy metabolism. To develop a disease-modifying…