S T U D Y P R O T O C O L Open Access
A randomized double-blind multi-center
trial of hydrogen water for Parkinson’s
disease: protocol and baseline
, Takashi Abe
, Chigumi Ohtsuka
, Tetsuya Maeda
, Masaaki Hirayama
, Hirohisa Watanabe
, Genko Oyama
, Jiro Fukae
, Yasushi Shimo
, Taku Hatano
, Sumihiro Kawajiri
, Yutaka Machida
, Hideto Miwa
, Chikako Suzuki
, Asuka Kazama
, Masahiko Tomiyama
, Motoyuki Hirasawa
, Hideki Shimura
and Nobutaka Hattori
Background: Our previous randomized double-blind study showed that drinking hydrogen (H
) water for 48 weeks
significantly improved the total Unified Parkinson’s Disease Rating Scale (UPDRS) score of Parkinson’s disease (PD)
patients treated with levodopa. We aim to confirm this result using a randomized double-blind placebo-controlled
Methods: Changes in the total UPDRS scores from baseline to the 8
, and 72
weeks, and after the
week, will be evaluated. The primary endpoint of the efficacy of this treatment in PD is the change in the total
UPDRS score from baseline to the 72
week. The changes in UPDRS part II, UPDRS part III, each UPDRS score, PD
Questionnaire-39 (PDQ-39), and the modified Hoehn and Yahr stage at these same time-points, as well as the
duration until the protocol is finished because additional levodopa is required or until the disease progresses, will
also be analyzed. Adverse events and screening laboratory studies will also be examined. Participants in the
hydrogen water group will drink 1000 mL/day of H
water, and those in the placebo water group will drink normal
water. One-hundred-and-seventy-eight participants with PD (89 women, 89 men; mean age: 64.2 [SD 9.2] years,
total UPDRS: 23.7 [11.8], with levodopa medication: 154 participants, without levodopa medication: 24 participants;
daily levodopa dose: 344.1 [202.8] mg, total levodopa equivalent dose: 592.0 [317.6] mg) were enrolled in 14
hospitals and were randomized.
Discussion: This study will confirm whether H
water can improve PD symptoms.
Trial registration: UMIN000010014 (February, 13, 2013)
Keywords: Hydrogen, oxidative stress, Parkinson’s disease, randomized double-blind placebo-controlled multicenter
* Correspondence: email@example.com
Department of Neurology, Juntendo University Koshigaya Hospital,
Fukuroyama 560, Koshigayashi, Saitama 343-0032, Japan
Department of Neurology, Juntendo University School of Medicine, Tokyo,
Full list of author information is available at the end of the article
© 2016 Yoritaka et al. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0
International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and
reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to
the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver
(http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
Yoritaka et al. BMC Neurology (2016) 16:66
In patients with Parkinson’s disease (PD), the pharmaco-
logic replacement of dopamine and other antiparkinsonian
drugs has been used for symptomatic therapy. However,
none of these drugs stop or lessen the dopaminergic neur-
onal degeneration or the progression of the disease. Find-
ings of increased iron and lipid peroxidation and decreased
levels of reduced glutathione in the substantia nigra
strongly suggest that enhanced oxidative stress is involved
in the pathogenesis of PD [1, 2]. Thus, antioxidant therapies
might slow the progression of PD. Molecular hydrogen
) has recently been highlighted as a therapeutic and pre-
ventive antioxidant. Since the first publication , more
than 150 papers have confirmed the efficacy of H
ous animal models . H
-water reduced dopaminergic
neuronal cell loss in a 1-methyl-4-phenyl-1,2,3,6-tetrahy-
dropyridine (MPTP) mouse model  as well as 6-
hydroxydopamine did . Our previous randomized
double-blind study has shown that drinking 1,000 mL of
-water for 48 weeks significantly improved (p<0.05) the
total Unified Parkinson’s Disease Rating Scale (UPDRS)
scores of patients with PD who were being treated with
levodopa . In the present study, we aimed to confirm
these results by conducting a longer and more large-scale
trial that also included patients who were not being treated
with levodopa. Here, we present the design and the baseline
characteristics of participants already enrolled in this study.
A placebo-controlled, randomized, double-blind, parallel-
group (1:1) clinical multi-center trial was organized by the
Department of Neurology of Juntendo University School
of Medicine in accordance with Consolidated Standards of
Reporting Trials (CONSORT) guideline. Fourteen hospi-
tals are involved as trial centers. This trial was advertised
in posters and on homepages of our clinic, and partici-
pants had to declare their intentions to participate volun-
tarily. The inclusion criteria required that the participants
have a diagnosis of PD according to the United Kingdom
Brain Bank criteria . All the participants should have a
modified Hoehn and Yahr staging (H & Y stage) in the on-
phase between 1 and 4. For 8 weeks prior to establishing
the baseline, the participants’antiparkinsonian drugs were
not changed. None of the participants have dementia
(MMSE < 25) or dysphagia for water. Outpatients are pre-
ferred over admitted patients. The participants are to be
older than 20 years. The exclusion criteria included the
following: parkinsonism due to diseases other than PD,
the presence of other serious diseases, malignant tumor(s),
or adverse events caused by drugs.
The clinical study is registered at UMIN clinical trial
registry (UMIN-CTR) UMIN000010014 (February 13,
2013). The Ethics Committee of the Juntendo University
School of Medicine approved this study in February
2013, as did the ethics committees of other centers, and
all participants provided signed informed consent forms.
Randomization and blinding
The enrolled participants have been assigned using a
stratified randomization method according to their age
and if they were receiving levodopa. The assignments
were made by C.S. The participants and those assessing
outcomes will remain blinded until all the participants
have finished the protocol.
On a daily basis, the participants will drink 1,000 mL of
-water containing 5 mM of dissolved H
(using Hydrogen 7.0, supplied by Ecomo International
Co., Ltd. [Fukuoka, Japan]; patent No: PCT/JP2011/
063601) for 72 weeks. The placebo water is saturated
. The water is contained in a 500-mL plastic bot-
tle, and the participants will drink 2 bottles per day. The
participants will drink the water within 3 h of opening
the cap, because H
evaporates. The bottles of H
or placebo water will be sent to the participants’home
The schedule of the study is shown in Fig. 1. Changes
in the total UPDRS scores from baseline to the 8
, and 72
weeks, and after the 8
week, are evalu-
ated. The primary endpoint of the efficacy of this treat-
ment in PD is the change in the total UPDRS score from
baseline to the 72
The changes in UPDRS part II, UPDRS part III, each
UPDRS score, PD Questionnaire-39 (PDQ-39), and the
H & Y stage at these same time-points, as well as the
duration until the protocol is finished because additional
levodopa is required or until the disease progresses, will
also be analyzed. Adverse events and screening labora-
tory parameters (total protein, albumin, alkaline phos-
phatase, aspartate transaminase, alanine transaminase,
serum urea nitrogen, calcium, chloride, creatinine, glu-
cose, lactate dehydrogenase, potassium, sodium, creatin-
ine kinase, uric acid, choline esterase, LDL-cholesterol,
HDL-cholesterol, and triglyceride levels) will also be
We calculated that a minimum of 95.4 participants need
to be enrolled to detect a 5-point difference in the
UPDRS scores between the 2 groups, with a standard
deviation of the mean difference of 10, and a 2-sided
alpha level of 0.05 and 80 %. Assuming a 35 % dropout,
96 participants will be required in total. A period of
72 weeks’follow-up is a relatively long-term clinical trial
in PD; hence, we assumed a 35 % dropout rate.
Yoritaka et al. BMC Neurology (2016) 16:66 Page 2 of 4
Variations in the endpoints between the baseline value
and treatment assessment points will be compared be-
tween the groups, using a t-test or a Mann–Whitney U-
test. The statistical tests are 2-sided, and the significance
level is set at 0.05. The number of participants in the
treatment and placebo groups who drop out due to dis-
ease progression will be analyzed using Kaplan −Meier
curves and the log-rank test. Subgroup analysis (sex, and
treatment with or without levodopa) will be performed.
Enrollment and data collection
One-hundred-and-seventy-eight Japanese participants
with PD have already been enrolled in 14 hospitals and
have been randomized, between April 1, 2013 and Sep-
tember 30, 2015, at their baseline visit. The participants
will be followed-up for 80 weeks. The baseline character-
istics are shown in Table 1. Despite extensive efforts to
enroll more participants, the expected number of partic-
ipants was not met, as it is difficult for some patients to
consume 1000 mL water daily.
Fujita et al. have indicated that the intake of H
even after MPTP administration, reduces neurotoxic
damage . The findings of our previous study  on
PD patients are in agreement with the previous results
that were obtained in animal models.
Antioxidant supplements that are considered medicinal
products should undergo sufficient evaluation before mar-
keting, as they might be harmful at high doses . H
lectively reduces •OH radicals, but not O
. It is expected that prolonged application of H
no or little adverse effects in chronic diseases. The effects
couldbemediatedbymodulating activities and ex-
pression of various molecules, such as Lyn, ERK, p38, JNK,
ASK1, Akt, GTP-Rac1, iNOS, Nox1, NF-κB, p65, Iκba,
STST3, NFATc1, c-Fos, and ghrelin . Iuchi et al. pro-
posed a hypothetical model in which H
is linked to the
Time point Enrolment Allocation Baseline/
0th week 1st day 8th week 24th week 48th week 72nd week After the
Hoehn and Yahr
Fig. 1 Schedule of enrolment, intervention, and assessment. Study period of enrolment, allocation, and baseline may coincide. It is approximately
1 week to 10 days from allocation to the first day to start shipping the water. *1: Unified Parkinson’s Disease Rating Scale. *2: Parkinson’s
Table 1 The baseline characteristics of the study participants
Mean Std. Deviation
Age 64.2 9.2
Disease duration 6.8 4.5
Sex (male/female) n 89 89
Wearing off (+/-) n 58 120
Dyskinesia (+/-) n 42 136
Levodopa mg 344.1 202.8
Levodopa (+/-) n 154 24
Dopamine agonist levodopa equivalent
dose (mg) 
Total levodopa equivalent dose (mg) 
Unified Parkinson’s Disease Rating Scale
Part I 0.7 1.2
Part II 5.6 3.9
Part III 15.7 8.4
Part IV 1.7 2.2
Total 23.7 11.8
Modified Hoehn and Yahr stage 2.1 0.6
Parkinson’s disease Questionnaire-39
Mobility 10.4 9.1
Activities of daily living 5.2 5.1
Emotional well-being 6.0 4.4
Stigma 3.2 2.8
Social support 1.4 1.9
Cognitions 4.0 3.0
Communication 1.7 2.2
Body discomfort 2.5 2.6
Total 34.4 24.2
: not including istradefylline and zonisamide
Yoritaka et al. BMC Neurology (2016) 16:66 Page 3 of 4
modulation of Ca
signal transduction and the nuclear fac-
tor of activated T cells (NFAT) pathway via oxidized
phospholipid species .
Our previous trial was the first randomized double-blind
study of H
-water in patients with PD . H
ited no adverse effects at a dose of 1000 mL/day in PD sub-
jects receiving levodopa treatment. The results of the
previous study will be confirmed in this longer and larger-
scale study that includes patients who are not medicated
with levodopa. This study will confirm the safety and toler-
ability of H
-water and if H
-water can improve PD
A randomized double-blind multi-center trial of hydro-
gen water for Parkinson’s disease was approved by the
Ethics Committee of the Juntendo University School of
Medicine, and the ethics committees of other centers.
Consent for publication
Availability of data and material
CONSORT: Consolidated Standards of Reporting Trials; H
: hydrogen; H &
Y: modified Hoehn and Yahr staging; MPTP: 1-methyl-4-phenyl-1,2,3,6-
tetrahydropyridine; NFAT: nuclear factor of activated T cells; PD: Parkinson’s
disease; PDQ-39: Parkinson’s disease Questionnaire-39; UPDRS: Unified
Parkinson’s Disease Rating Scale.
N. Hattori has served as an advisory board member for Boehringer Ingelheim
and FP Pharmaceutical Company (PC) and he has consulted for Ohtsuka PC,
Kyowa Hakko Kirin PC, GlaxoSmithKline, Novartis, Abbot, Hisamitsu, and
Schering-Plough (MSD); he also received personal compensation for attend-
ing these advisory board meetings. Other authors: None
AY conceived and designed the study, acquired data, performed statistical
analysis, and drafted and revised the manuscript. TA, CO, TM, HW, MH, SK,
YO, HS, GO, JF, YS, TH, YM, HM, MT, MH, and HS acquired the data. CS
performed randomization. AK helped in checking the data. TK acquired the
data and revised the manuscript. NH conceived the study and revised the
manuscript. All authors read and approved the final manuscript.
We thank MiZ Co. Ltd. and Ecomointernational Co., Ltd. for supplying the
Suisosui 7.0 (H
-water) and placebo water.
This work is supported by a grant from Japan Society for the Promotion of
Science KAKENHI (Grant Number 15 K09360).
Department of Neurology, Juntendo University Koshigaya Hospital,
Fukuroyama 560, Koshigayashi, Saitama 343-0032, Japan.
Neurology, Juntendo University School of Medicine, Tokyo, Japan.
Department of Neurology, Abe Neurological Clinic, Iwate, Japan.
Department of Neurology and Gerontology, Iwate Medical University, Iwate,
Department of Neurology, Research Institute for Brain and Blood
Vessels-Akita Hospital, Akita, Japan.
Department of Pathophysiological
Laboratory Sciences, Nagoya University Graduate School of Medicine, Aichi,
Brain and Mind Research Center, Nagoya University Graduate School
of Medicine, Aichi, Japan.
Department of Neurology, Kitano Hospital, The
Tazuke Kofukai Medical Research Institute, Osaka, Japan.
Neurology, Fukuoka University, Fukuoka, Japan.
Department of Neurology,
Juntendo University Shizuoka Hospital, Shizuoka, Japan.
Neurology, Juntendo University Nerima Hospital, Tokyo, Japan.
of Diagnostic Radiology, Department of Molecular Medicine and Surgery,
Karolinska University Hospital, Karolinska Institute, Stockholm, Sweden.
Nozomi Hospital, Saitama, Japan.
Department of Neurology, Aomori
Prefectural Central Hospital, Aomori, Japan.
Department of Neurology,
Rakuwakai Otowa Rehabilitation Hospital, Kyoto, Japan.
Neurology, Tokyo Rinkai Hospital, Tokyo, Japan.
Department of Neurology,
Juntendo University Urayasu Hospital, Chiba, Japan.
Received: 21 March 2016 Accepted: 5 May 2016
1. Dexter DT, Wells FR, Agid F, Lees AJ, Jenner P, Marsden CD. Increased nigral
iron content in postmortem Parkinsonian brain. Lancet. 1987;8569:1219–20.
2. Yoritaka A, Hattori N, Uchida K, Tanaka M, Stadtman ER, Mizuno Y.
Immunohistochemical detection of 4-hydroxynonenal protein adducts in
Parkinson disease. Proc Natl Acad Sci USA. 1996;93:2696–701.
3. Ohsawa I, Ishikawa M, Takahashi K, et al. Hydrogen acts as a therapeutic
antioxidant by selectively reducing cytotoxic oxygen radicals. Nat Med.
4. Ohta S. Molecular hydrogen is a novel antioxidant to efficiently reduce
oxidative stress with potential for the improvement of mitochondrial
diseases. Biochim Biophys Acta. 1820;2012:586–94.
5. Fujita K, Seike T, Yutsudo N, et al. Hydrogen in drinking water reduces
dopaminergic neuronal loss in the 1-methyl-4-phenyl-1,2,3,6-
tetrahydropyridine mouse model of Parkinson’s disease. PLoS One.
6. Fu Y, Ito M, Fujita Y, et al. Molecular hydrogen is protective against
6-hydroxydopamine-induced nigrostriatal degeneration in a rat model of
Parkinson’s disease. Neurosci Lett. 2009;453:81–5.
7. Yoritaka A, Takanashi M, Hirayama M, Nakahara T, Ohta S, Hattori N. Pilot
study of H2 therapy in Parkinson’s disease: A randomized double-blind
placebo-controlled trial. Mov Disord. 2013;28:836–9.
8. Hughes AJ, Daniel SE, Kilford L, Lees AJ. Accuracy of clinical diagnosis of
idiopathic Parkinson’s disease: a clinico-pathological study of 100 cases. J
Neurol Neurosurg Psychiatry. 1992;55:181–4.
9. Bjelakovic G, Nikolova D, Gluud LL, Simonetti RG, Gluud C. Mortality in
randomized trials of antioxidant supplements for primary and secondary
prevention: systematic review and meta-analysis. JAMA. 2007;28:842–57.
10. Ichihara M, Sobue S, Ito M, Ito M, Hirayama M, Ohno K. Beneficial biological
effects and the underlying mechanisms of molecular
hydrogen—comprehensive review of 321 original articles. Med Gas Res.
11. Iuchi K, Imoto A, Kamimura N, et al. Molecular hydrogen regulates gene
expression by modifying the free radical chain reaction-dependent
generation of oxidized phospholipid mediators. Sci Rep. 2016;6:18971.
12. Tomlinson CL, Stowe R, Patel S, Rick C, Gray R, Clarke CE. Systematic review
of levodopa dose equivalency reporting in Parkinson’s disease. Mov Disord.
• We accept pre-submission inquiries
• Our selector tool helps you to ﬁnd the most relevant journal
• We provide round the clock customer support
• Convenient online submission
• Thorough peer review
• Inclusion in PubMed and all major indexing services
• Maximum visibility for your research
Submit your manuscript at
Submit your next manuscript to BioMed Central
and we will help you at every step:
Yoritaka et al. BMC Neurology (2016) 16:66 Page 4 of 4
Terms and Conditions
Springer Nature journal content, brought to you courtesy of Springer Nature Customer Service Center GmbH (“Springer Nature”).
Springer Nature supports a reasonable amount of sharing of research papers by authors, subscribers and authorised users (“Users”), for small-
scale personal, non-commercial use provided that all copyright, trade and service marks and other proprietary notices are maintained. By
purposes, Springer Nature considers academic use (by researchers and students) to be non-commercial.
These Terms are supplementary and will apply in addition to any applicable website terms and conditions, a relevant site licence or a personal
subscription. These Terms will prevail over any conflict or ambiguity with regards to the relevant terms, a site licence or a personal subscription
(to the extent of the conflict or ambiguity only). For Creative Commons-licensed articles, the terms of the Creative Commons license used will
We collect and use personal data to provide access to the Springer Nature journal content. We may also use these personal data internally within
ResearchGate and Springer Nature and as agreed share it, in an anonymised way, for purposes of tracking, analysis and reporting. We will not
otherwise disclose your personal data outside the ResearchGate or the Springer Nature group of companies unless we have your permission as
While Users may use the Springer Nature journal content for small scale, personal non-commercial use, it is important to note that Users may
use such content for the purpose of providing other users with access on a regular or large scale basis or as a means to circumvent access
use such content where to do so would be considered a criminal or statutory offence in any jurisdiction, or gives rise to civil liability, or is
falsely or misleadingly imply or suggest endorsement, approval , sponsorship, or association unless explicitly agreed to by Springer Nature in
use bots or other automated methods to access the content or redirect messages
override any security feature or exclusionary protocol; or
share the content in order to create substitute for Springer Nature products or services or a systematic database of Springer Nature journal
In line with the restriction against commercial use, Springer Nature does not permit the creation of a product or service that creates revenue,
royalties, rent or income from our content or its inclusion as part of a paid for service or for other commercial gain. Springer Nature journal
content cannot be used for inter-library loans and librarians may not upload Springer Nature journal content on a large scale into their, or any
other, institutional repository.
content on this website and may remove it or features or functionality at our sole discretion, at any time with or without notice. Springer Nature
may revoke this licence to you at any time and remove access to any copies of the Springer Nature journal content which have been saved.
To the fullest extent permitted by law, Springer Nature makes no warranties, representations or guarantees to Users, either express or implied
with respect to the Springer nature journal content and all parties disclaim and waive any implied warranties or warranties imposed by law,
including merchantability or fitness for any particular purpose.
Please note that these rights do not automatically extend to content, data or other material published by Springer Nature that may be licensed
from third parties.
If you would like to use or distribute our Springer Nature journal content to a wider audience or on a regular basis or in any other manner not
expressly permitted by these Terms, please contact Springer Nature at