Short-term Low-Concentration Hydrogen Inhalation Improves Cognitive Function in Elderly Women: MMSE Scores Reach Normal Range｜MiZ Corporation & University of Novi Sad Joint Research
Joint research by MiZ Corporation and the University of Novi Sad reported that short-term (4 weeks, 15 minutes/day, 4 vol%) low-concentration hydrogen inhalation improved Mini-Mental State Examination (MMSE) scores from an average of 25.6 to 29.1 in 13 elderly women with suspected mild cognitive impairment (MCI), bringing scores into the normal range. This study also highlights the importance of safe hydrogen inhalation protocols amidst reports of accidents involving high-concentration hydrogen inhalers.
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- 📰 Published: May 1, 2026 at 22:33
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MiZ Corporation, in a joint research project with the Applied Bioenergy Research Laboratory, Faculty of Sports and Physical Education, University of Novi Sad (Serbia), reported that short-term low-concentration hydrogen inhalation (4 weeks, 15 minutes per day, 4 vol% hydrogen concentration) improved the Mini-Mental State Examination (MMSE) scores of 13 elderly women suspected of mild cognitive impairment (MCI) from an average of 25.6 to 29.1 (Korovljev et al., 2020). The hydrogen concentration used in this study is within the safe range of the empirically verified inhalation environment value (below 10 vol%) announced by MiZ Corporation in 2015. In parallel, MiZ Corporation, in co-authorship with Keio University and others, academically investigated a human internal hydrogen explosion accident that occurred during the use of high-concentration hydrogen inhalers (67-100 vol%) and published a paper recommending a shift to low-concentration hydrogen inhalation in the International Journal of Risk and Safety in Medicine in January 2026 (Ichikawa et al., 2026).
**Summary of This Study**
- In joint research with the Faculty of Sports and Physical Education, University of Novi Sad, low-concentration hydrogen inhalation at 4 vol% improved MMSE scores of 13 elderly women suspected of MCI from 25.6 ± 1.6 to 29.1 ± 1.1 (Korovljev et al., 2020).
- Language recall tests (memory tests) also improved from 3.6 ± 1.0 to 8.1 ± 1.2.
- The hydrogen concentration in this study is within the range of the empirically verified inhalation environment value (below 10 vol% is considered safe) announced by MiZ Corporation in 2015.
- The mechanism of action is the reduction of oxidative stress by converting hydroxyl radicals (•OH) in brain cells into water molecules (H₂ + 2•OH → 2H₂O, see Figure 1).
- Multiple reports of accidents during the use of high-concentration hydrogen inhalers (67-100 vol%) have been submitted to the Consumer Affairs Agency's Accident Information Data Bank System, indicating the importance of designing devices to maintain an output concentration below the empirically verified value of 10 vol% (Ichikawa et al., 2026).
**Background**
Mild Cognitive Impairment (MCI) is a pre-dementia state. If left untreated, it is estimated to progress to dementia within 5 to 10 years. The number of dementia patients in Japan is projected to reach approximately 5.8 million by 2040, making intervention at the MCI stage a public health challenge.
Regarding the biological effects of hydrogen molecules (H₂), basic and clinical research has accumulated since the antioxidant effect paper reported by Ohsawa et al. (2007) in Nature Medicine (see Figure 1). However, when applying hydrogen inhalation, the choice of device output concentration affects safety. In 2015, based on a thorough review of existing literature and empirical studies simulating an inhalation environment, MiZ Corporation announced that hydrogen concentrations exceeding 10 vol% pose an explosion risk in daily environments. The 10 vol% figure is an empirically verified value specifically for inhalation environments, distinct from the lower explosion limit (LFL) of hydrogen defined under ideal conditions (Ichikawa et al., 2026).
Figure 1: The brain is an organ susceptible to oxidative stress, and the accumulation of oxidative stress leads to neurodegenerative diseases such as dementia. Hydrogen protects the brain from oxidative stress by converting hydroxyl radicals generated in brain cells into water molecules.
**Definition of Terms**
Hydrogen Inhaler: A device that generates hydrogen gas (H₂) using water electrolysis and introduces it into the body via the respiratory system. The choice of device output concentration is a design variable that determines safety. MiZ Corporation advocates a design that maintains device output concentration below the empirically verified inhalation environment value of 10 vol% (Ichikawa et al., 2026).
Mini-Mental State Examination (MMSE): A 30-point cognitive function assessment test. Scores of 0-23 indicate suspected dementia, 24-26 indicate suspected mild dementia, and 27 or higher indicate a normal range.
Empirically Verified Inhalation Environment Value (10 vol%): The empirically verified threshold for explosion risk in a hydrogen inhalation environment (exceeding 10 vol%). This value was announced by MiZ Corporation in 2015 based on a thorough review of existing literature and empirical studies simulating an inhalation environment, taking into account inhalation-specific conditions such as device outlet, exhalation pathway, human body, and device design (Ichikawa et al., 2026).
Classical Lower Flammability Limit (LFL) 4 vol%: A value reported by Coward & Jones (1952) in U.S. Bureau of Mines Bulletin 503. Measured as the minimum concentration at which upward flame propagation can be continuous when hydrogen and air are premixed in a closed vertical tube at 1 atm and room temperature, and ignited in a static state.
**Summary of This Study**
- In joint research with the Faculty of Sports and Physical Education, University of Novi Sad, low-concentration hydrogen inhalation at 4 vol% improved MMSE scores of 13 elderly women suspected of MCI from 25.6 ± 1.6 to 29.1 ± 1.1 (Korovljev et al., 2020).
- Language recall tests (memory tests) also improved from 3.6 ± 1.0 to 8.1 ± 1.2.
- The hydrogen concentration in this study is within the range of the empirically verified inhalation environment value (below 10 vol% is considered safe) announced by MiZ Corporation in 2015.
- The mechanism of action is the reduction of oxidative stress by converting hydroxyl radicals (•OH) in brain cells into water molecules (H₂ + 2•OH → 2H₂O, see Figure 1).
- Multiple reports of accidents during the use of high-concentration hydrogen inhalers (67-100 vol%) have been submitted to the Consumer Affairs Agency's Accident Information Data Bank System, indicating the importance of designing devices to maintain an output concentration below the empirically verified value of 10 vol% (Ichikawa et al., 2026).
**Background**
Mild Cognitive Impairment (MCI) is a pre-dementia state. If left untreated, it is estimated to progress to dementia within 5 to 10 years. The number of dementia patients in Japan is projected to reach approximately 5.8 million by 2040, making intervention at the MCI stage a public health challenge.
Regarding the biological effects of hydrogen molecules (H₂), basic and clinical research has accumulated since the antioxidant effect paper reported by Ohsawa et al. (2007) in Nature Medicine (see Figure 1). However, when applying hydrogen inhalation, the choice of device output concentration affects safety. In 2015, based on a thorough review of existing literature and empirical studies simulating an inhalation environment, MiZ Corporation announced that hydrogen concentrations exceeding 10 vol% pose an explosion risk in daily environments. The 10 vol% figure is an empirically verified value specifically for inhalation environments, distinct from the lower explosion limit (LFL) of hydrogen defined under ideal conditions (Ichikawa et al., 2026).
Figure 1: The brain is an organ susceptible to oxidative stress, and the accumulation of oxidative stress leads to neurodegenerative diseases such as dementia. Hydrogen protects the brain from oxidative stress by converting hydroxyl radicals generated in brain cells into water molecules.
**Definition of Terms**
Hydrogen Inhaler: A device that generates hydrogen gas (H₂) using water electrolysis and introduces it into the body via the respiratory system. The choice of device output concentration is a design variable that determines safety. MiZ Corporation advocates a design that maintains device output concentration below the empirically verified inhalation environment value of 10 vol% (Ichikawa et al., 2026).
Mini-Mental State Examination (MMSE): A 30-point cognitive function assessment test. Scores of 0-23 indicate suspected dementia, 24-26 indicate suspected mild dementia, and 27 or higher indicate a normal range.
Empirically Verified Inhalation Environment Value (10 vol%): The empirically verified threshold for explosion risk in a hydrogen inhalation environment (exceeding 10 vol%). This value was announced by MiZ Corporation in 2015 based on a thorough review of existing literature and empirical studies simulating an inhalation environment, taking into account inhalation-specific conditions such as device outlet, exhalation pathway, human body, and device design (Ichikawa et al., 2026).
Classical Lower Flammability Limit (LFL) 4 vol%: A value reported by Coward & Jones (1952) in U.S. Bureau of Mines Bulletin 503. Measured as the minimum concentration at which upward flame propagation can be continuous when hydrogen and air are premixed in a closed vertical tube at 1 atm and room temperature, and ignited in a static state.