How Water Type and Storage Affect Hydrogen Water Quality and Benefits

Authors
Journal
Medical Gas Research
Year
DOI
10.4103/2045-9912.285559
Study Type
Human
Outcome
Positive
Peer Reviewed
Yes
Country
Japan
Health Condition
Oxidative Stress
Body System
Oral Health

TL;DR

This study shows that the quality of water before electrolysis, temperature, and container material affect the levels of hydrogen and antioxidant potential in hydrogen-water, which can temporarily alter the antioxidant properties of saliva when used for oral care or drinking.

Key Finding

Mineral content, temperature, and container material significantly affect how much hydrogen remains dissolved in hydrogen-water, with aluminum and stainless steel containers preserving hydrogen far better than plastics.

Summary

Researchers tested how different water properties and storage methods affect the amount of dissolved hydrogen in hydrogen-water made by electrolysis machines. They found that water with more minerals produced less hydrogen, pure water produced very little hydrogen, and temperature affected hydrogen levels. Metal containers (aluminum and stainless steel) kept hydrogen in the water much better than plastic containers. When people rinsed their mouth or drank hydrogen-water, their saliva showed temporary changes in oxidation-reduction potential (a measure related to oxidative stress), and drinking it regularly for several weeks appeared to cause longer-lasting changes.

Practical Takeaway

If you use a hydrogen-water generator, this study suggests using mineral-rich or moderately hard water rather than purified water, keeping the water cool, and storing it in metal rather than plastic containers to maintain hydrogen levels. The study also indicates that drinking hydrogen-water may produce temporary changes in mouth chemistry, though the long-term significance of these changes is unclear and requires further research.

Abstract

Widely distributed electrolytic-generators for hydrogen-water are not fully considered for the dependencies of post-electrolytic values of the dissolved hydrogen concentration (DH) and the oxidation-reduction potential (ORP) on the properties of the pre-electrolytic water. We investigated the dependencies of DH and ORP on mineral-based hardness, temperatures and the container materials, and effects on the oral cavity by oral washing or drinking. Along with an increase in mineral-based water-hardness, DH decreased from 960 to 870 μg/L and the ORP unexpectedly increased from -460 to -320 mV. Purified water of almost zero hardness, however, caused a post-electrolytic DH as low as 80 μg/L and an ORP as high as +20 mV. Post-electrolytic DHs were not significantly changed (780-900 μg/L) upon electrolysis at 1.5-30°C and decreased at 40-50°C. The diffusion of hydrogen from the inside to the outside of the container was extremely small even after 12 hours for an aluminum- or stainless steel-made container, but not for containers made of diverse plastics. The ORP of the intact saliva was +136 mV, and decreased to +90 mV at 20 minutes after 1-minute oral-cramming of hydrogen-water, but returned to +135 mV after 60-minute leaving, showing a transient ORP-decrease in the saliva. Drinking-pause for 4 weeks after drinking hydrogen-water, however, saliva ORP, gradually but not instantly, increased to +60 to +80 mV, but upon drinking-resumption and 2 weeks thereafter, decreased again to -100 to -110 mV, suggesting that several-week hydrogen-water drinking caused a certain decrease in the saliva ORP. Thus, the present study provided the appropriate conditions such as hardness and temperatures for hydrogen-water production by the electrolytic generator, and the container materials suitable for hydrogen-water preservation. Furthermore, we clarified ORP changes of human saliva, being an indicator for human oxidative stress. The study was approved by the Medical Ethics Committee of the NPO (Non-Profitable Organization)-Corporate Japanese Center for Anti-Aging Medical Sciences (approval No. 09S02) on May 2, 2012.