Hydrogen Water Prevents Memory Loss from Chronic Stress in Mice
- Authors
- Kazufumi Nagata, Naomi Nakashima-Kamimura, Toshio Mikami, Ikuroh Ohsawa, Shigeo Ohta
- Journal
- Neuropsychopharmacology
- Year
- 2009
- DOI
- 10.1038/npp.2008.95
- Study Type
- Rat
- Outcome
- Positive
- Peer Reviewed
- Yes
- Country
- Japan
- Health Condition
- Cognitive Impairment
- Body System
- Nervous System
TL;DR
Drinking hydrogen-enriched water can protect against memory and learning problems in mice caused by stress, by reducing harmful oxidative stress in the brain.
Key Finding
Drinking hydrogen water throughout chronic stress prevented mice from developing stress-induced learning and memory problems by reducing oxidative stress in the brain and promoting new cell growth in the hippocampus.
Summary
Researchers gave mice chronic stress through physical restraint and found that drinking hydrogen-enriched water prevented the stress-related decline in learning and memory. The hydrogen water reduced harmful molecules called oxidative stress markers in the brain and boosted the growth of new brain cells in a region important for memory (the hippocampus). However, hydrogen water did not improve learning in unstressed mice, suggesting it specifically counteracts stress-related cognitive damage.
Practical Takeaway
This animal study suggests hydrogen water may help protect cognitive function under chronic stress conditions, but it's early-stage research in mice only. The finding that hydrogen water didn't improve cognition in non-stressed animals suggests it may work as a stress-protective measure rather than a general cognitive enhancer. Human studies would be needed to determine if these results apply to people.
Abstract
We have reported that hydrogen (H(2)) acts as an efficient antioxidant by gaseous rapid diffusion. When water saturated with hydrogen (hydrogen water) was placed into the stomach of a rat, hydrogen was detected at several microM level in blood. Because hydrogen gas is unsuitable for continuous consumption, we investigated using mice whether drinking hydrogen water ad libitum, instead of inhaling hydrogen gas, prevents cognitive impairment by reducing oxidative stress. Chronic physical restraint stress to mice enhanced levels of oxidative stress markers, malondialdehyde and 4-hydroxy-2-nonenal, in the brain, and impaired learning and memory, as judged by three different methods: passive avoidance learning, object recognition task, and the Morris water maze. Consumption of hydrogen water ad libitum throughout the whole period suppressed the increase in the oxidative stress markers and prevented cognitive impairment, as judged by all three methods, whereas hydrogen water did not improve cognitive ability when no stress was provided. Neural proliferation in the dentate gyrus of the hippocampus was suppressed by restraint stress, as observed by 5-bromo-2'-deoxyuridine incorporation and Ki-67 immunostaining, proliferation markers. The consumption of hydrogen water ameliorated the reduced proliferation although the mechanistic link between the hydrogen-dependent changes in neurogenesis and cognitive impairments remains unclear. Thus, continuous consumption of hydrogen water reduces oxidative stress in the brain, and prevents the stress-induced decline in learning and memory caused by chronic physical restraint. Hydrogen water may be applicable for preventive use in cognitive or other neuronal disorders.