Yonago Acta Medica 2022;65(3):184–190 doi: 10.33160/yam.2022.08.001

Review Article: Special Contribution

Dementia Prevention and Aromatherapy in Japan
Katsuya Urakami** Department of Dementia Prevention, School of Health Science, Faculty of Medicine, Tottori University, Yonago 683-8503, Japan

ABSTRACT
Until recently, it was thought that dementia prevention
was not possible. However, a recent paper reported that
40% of the risk factors for developing dementia aremodifiable. Large-scale clinical studies on dementia
prevention and various initiatives to reduce the riskof developing dementia have been made worldwide.
In addition to the introduction of a global initiative indementia prevention, I also introduce the results ofour research on the development of the Tottori method
dementia prevention program and aromatherapy to approach olfactory impairment in Alzheimer’s disease.
Alzheimer’s disease; aromatherapy; MCI;
non-pharmacological treatment; olfactory impairment
Key words

Currently, there is no cure for dementia; therefore,
its prevention has gathered increasing attention.1 In
the case of Alzheimer’s disease, a dementia-causing
disease, deposition of amyloid β-protein appeared
as an early pathological change.2 The aggregation ofamyloid β-protein becomes insoluble.3 This leads tothe formation of senile plaques, followed by changes inneurofibrillary tangles through the deposition of phosphorylated tau protein, which finally results in neuronalcell death.4 It was believed that neurodegeneration
pathway was irreversible. In recent years, however, it
has become clear that amyloid β-proteins can, in fact bysolublilised,5 not only by drugs6 but also by non-drugs.7
The former is the fundamental medical treatment for
Alzheimer’s disease, while the latter is being taken up asa preventive treatment. This study focuses on preventive
treatments for dementia, specifically on aromatherapy,
which has recently attracted attention.

Corresponding author: Katsuya Urakami, MD, PhD
kurakami@tottori-u.ac.jp
Received 2021 October 13
Accepted 2022 June 30
Online published 2022 August 1
Abbreviations: ADAS, Alzheimer’s disease assessment scale;
GBS scale, the Gottfries-Brane-Steen scale; MCI, mild cognitive
impairment; OSIT-J, the Odor Stick identification test for Japanese, ROC, Receiver Operating Characteristic; SAMP8 mice,senescence-accelerated 8 mice; TDAS, Touch panel-type dementia assessment scale

184

DEFINITION OF DEMENTIA PREVENTION
For all diseases, including dementia, there are different types of prevention. Primary prevention refers to
predicting the onset of diseases. Secondary prevention
involves the early detection and treatment of diseases.
Tertiary prevention entails stopping the progression of
diseases. In general, people associate preventive treatments with primary prevention, but the broader definition of prevention, from primary to tertiary, should be
kept in mind for the prevention of all diseases. Since
dementia is no longer considered a special disease, it isappropriate to use this broader concept for its prevention
as well. The present study describes primary prevention
strategies for dementia.
RISK FACTORS FOR DEMENTIA
In 2017,8 it was revealed that 35% of the identified risk
factors for dementia can be modified among the risk
factors. Previously, none of the risk factors were known
to be modifiable. Further, risk factors differ among age
groups. For instance, in early life, risk factors for dementia include less education,9 in midlife they include
hearing loss,10 hypertension,11 and obesity,12 and inlate life they include smoking,13 depression,14 physicalinactivity,15 social isolation,16 and diabetes.17 Therefore,
prevention strategies should be tailored to specific age
groups.
For example, obesity is a risk factor in midlife,
but not in late life. Therefore, taking measures against
obesity in midlife is useful, but taking similar measuresin other life stages would not contribute to dementia
prevention. Specifically, aerobic exercise is highly recommended as a measure against obesity, but continuingsuch exercises in late life is likely to lead to muscle
volume loss and weakness. Instead in late life, muscle
training should be emphasised.
Surprisingly, hearing loss (9%) is considered thehighest risk factor.8 Thus, hearing loss treatment should
be sought immediately, and hearing aids should be worn
as soon as possible. Hearing training for less severecases of hearing loss will also be needed in the near
future.
More recently, in 2020, a review18 of the literatureon risk factors for dementia reported an increase in
the percentage of risk factors that are modifiable (i.e.
40%). It is expected that more factors will be found to© 2022 Tottori University Medical PressDementia prevention and aromatherapy

be modifiable in the future, including traumatic brain
injury19 and excessive alcohol intake20 in midlife, andair pollution21 in late life.
DEMENTIA PREVENTION ACTIVITIESThe most appropriate target for dementia prevention
activities is people with mild cognitive impairment(MCI).22 MCI is commonly referred to as the pre-stageof dementia.23 While dementia is irreversible, MCI is areversible condition.24 As of 2012, 4 million people had
been diagnosed with MCI in Japan.25 It is, of course,
important for people with normal cognitive function
to engage in dementia prevention activities, but they
are less likely to develop dementia than those with
MCI. Therefore, the outcome of prevention activities is
unknown for people with normal cognitive function.
MCI has been found to progress to dementia in 10–
20% of cases each year, which highlight is why people
with MCI are the most suitable subjects for dementia
prevention from an outcome perspective.26 However,
it is not easy to detect MCI. Consequently, I have developed computer-based screening method with touchpanel type for early and easy detection of MCI.27, 28 As a
primary screening method, a program for forgetfulness
consultation was created, which evaluates the threemost important cognitive functions for the early detection of dementia: delayed recall, orientation of time, andvisuospatial ability. These questions can be answered
within 3–5 minutes. The results are then obtained bymeans of Receiver Operating Characteristic (ROC)
analysis with 96% sensitivity and 97% specificity (i.e.
extremely high accuracy). Scores range from 0 (i.e. allincorrect) to 15 (i.e. all correct). Since this non-invasive
screening method is convenient to carry around and is
not affected by administration bias, it is considered to
be an optimum tool for forgetfulness detection.27 For
individuals with scores from 7–13, MCI is suspected
and secondary medical examination is recommended
for the doctor (dementia specialist) and/or public healthnurse to explain the results and provide counselling. The
TDAS computer system and the Alzheimer’s Disease
Assessment Scale (ADAS) significantly correlated 28
suggesting they evaluate the same things. The ADAS isa reliable scale, that has been used worldwide to assess
drugs for Alzheimer’s disease treatment. Unfortunately,
the ADAS is rarely used in clinical practice because
it has to be administered by a clinical psychologist or
licensed professional and it takes about one hour tocomplete. In rural Japan, there are very few licensed
clinical psychologists, making it difficult for the ADAS
to be employed as screening tool. Even if we luckily
employ one person, it is only 8 people maximum we

can examine ADAS through the whole day. In order tosolve these problems, we developed the TDAS program.
The TDAS, on the other hand, can be completed in
10–15 minutes without a specialist or licensed clinicalpsychologist.
TDAS scores of 6 or less indicates normal cognitive state, scores from 7–13 indicates MCI, and scoresof 14 or more suggest suspected dementia. For people
with normal cognitive state, we recommend that they
undergo screening for forgetfulness in next year. For
those who score 14 or more, we recommend that they
visit a medical hospital specializing in dementia.
Finally, for those who the score 7–13, indicating MCI,
we recommend that they participate in dementia prevention classes. These classes include 12 weekly sessions of
two hours each for three months. Prevention activities
in this class consist of three components: physicalexercise, intellectual activities and communication.
Physical exercise includes a range of activities, fromworkouts to elements of game property. Intellectual
activities involve keeping the mind active from learning
actions to incorporating elements of game property.
Communication activities entail enjoying and participating in conversation with other participants and staff
members. Communication is important, especially for
elderly people living alone since a lifestyle with little
conversation predisposes to dementia.
Difference of TDAS before and after MCI in dementia prevention class with suitable three components
for prevention was statistically significant.29 In addition,
we found that MCI had been kept in good condition forthree years. At the same time, we validated the economic effects in Kotoura-cho (study field), Tottori prefecture.
This initiative became one of the factors contributing to
the 26 (1.5%reduction overall) and 78 (4.3% reduction
overall) million yen reduction in care insurance in 2014
and 2018, respectively. Although it is not so high as apercentage, it is quite a large amount (tens of millionsof yen) in terms of the amount, and highly appreciatedby many people. Such reductions can increase if wemaintain our efforts. This initiative, which started in
Kotoura-cho, Tottori prefecture has been implemented
in numerous cities, towns, and villages in the Tottori
prefecture and others.
APPROACH AND ISSUE ON THE PROGRAMFOR FORGETFULNESS AND DEMENTIA PREVENTION CLASSES
Although both the forgetfulness detection survey anddementia prevention classes have been successful. For
instance, the number of participants is not increasing,possibly due to social prejudices about dementia. We
185© 2022 Tottori University Medical Press

K. Urakami

have spread enlightenment that “dementia can be treatedand prevented if it occurs at an early stage, but is not yet
knoun”
Specifically, human resources development shouldbe established in the dementia prevention class. Seven
dementia prevention classes were conducted during
around the same times. Although all participants
showed improved TDAS scores after participation,
the degree of improvement varied greatly among classgroups, despite similar programs being imparted.30 Thismight be due to differences in the class coordinators’knowledge and skills for dementia prevention. Whilevolunteer work can be accepted, we think that it would
be desirable to involve professionals with expertise indementia prevention.
Therefore, the Japanese Society of Dementia
Prevention has established a specialist system for theprevention of dementia and has been developing humanresources for the same.
DEVELOPMENT AND DISSEMINATION OF THE
TOTTORI METHOD DEMENTIA PREVENTIONPROGRAMThe study of Tottori Method Dementia Prevention
Program Development was conducted in Houki-chowith the aim of upgrading the dementia prevention
initiative in Kotoura-cho, Tottori Prefecture, which has
been conducted since 2004, and to provide scientificevidence of its effectiveness.31 The method used in
Kotoura-cho was to select individuals with diagnosed
with MCI from among older adults living in the community using the forgetfulness consultation programsystem and TDAS, and to examine the effectiveness ofthe dementia prevention class by dividing the individuals into two groups: (intervention-first and observationfirst). The former received the intervention in the firsthalf of the program, and observation only in the latter
half. The observation-first group received observationin the former half and intervention in the latter half.
Significant differences were obtained between theintervention and observation periods. The contents ofthe dementia prevention class were upgraded versionsof the exercises and intellectual, and communication
activities that had been conducted in Kotoura-cho. The
exercise programs included warm-ups, aerobic, muscle
strength training, and cool-down sessions. Since toomuch aerobic exercise is not good for the elderly, a goodbalance of aerobic and muscle strength exercises wasprovided. Stretching exercises were included in thewarm-up and cooling-down exercises to improve flexibility. Intellectual activities were designed to stimulate
all eight types of cognitive functions and were divided

Fig. 1. Improvement in cognitive function through intervention.
Improvement in cognitive function was observed through intervention with the prevention program using the TDAS (P = 0.017).
Mann-Whitney U test was used for statistical analysis. The verticalaxis shows the TDAS score. TDAS, Touch panel type dementia
assessment scale.

into individual and group activities. Communication
activities included having a chat over a cup of tea during
breaks between exercise and intellectual activities.
Cognitive function was assessed using the TDAS,
and significant improvement was observed as a result of
the intervention (i.e. dementia prevention classes: Fig.
1).32 The physical activity assessment showed significant improvements in upper limb strength, lower limb
strength and flexibility (Fig. 2).32 Improvement in lower
limb muscle strength can help prevent falls by allowing the patient balance themselves when about to fall.
Flexibility also helps prevent fractures in case of falls.
Bone fractures in the elderly are known to be a risk
for the progression and worsening of dementia; thus,
preventing falls is essential for dementia prevention.
As I have been able to scientifically verify the effectiveness of the Tottori Method Dementia Prevention
Program, we are now promoting this program in Tottori
Prefecture and throughout Japan.
IMPROVEMENT OF DEMENTIA WITH AROMATHERAPY
Given that Alzheimer’s disease is caused by olfactory dysfunction,33 we investigated the possibility ofearly detection of dementia by olfactory testing andprevention of dementia by stimulating the olfactory
nerve with aromatherapy. There are many diseases thatcause dementia, but Alzheimer’s disease accounts for186© 2022 Tottori University Medical PressDementia prevention and aromatherapy

Fig. 2. Improvement of body function through intervention. The physical activity assessment showed significant improvements between
intervention and observation period in upper limb strength (P < 0.0001), lower limb strength (P < 0.0021) and flexibility (P < 0.0001)
through intervention with the prevention program. Unpaired-t test and Mann-Whitney U test were used for statistical analysis.

Fig. 3. Olfactory impairment in AD compared to age-matched controls (OSIT-J). Olfactory impairment in early stage of AD is shown
compared to age-matched controls using OSIT-J kit (P < 0.01). Mann-Whitney U test was used for statistical analysis. The vertical axis
shows the OSIT-J score, the lower the score, the lower the sense of smell. AD, Alzheimer’s disease; OSIT-J, the Odor Stick identification
test for Japanese.

about 70% of all dementia cases.34 The first symptomof Alzheimer’s disease has been said to be memory
impairment, but in reality, the first symptom is olfactory
impairment due to damage to the olfactory nerve. Using
the Odor Stick Identification test for Japanese people(OSIT-J), it was found that the olfactory function of
Alzheimer’s disease patients is lower than that of agematched controls.35 Furthermore, we confirmed that
their olfactory function was impaired from an earlystage of Alzheimer’s disease (Fig. 3). Pathologically, it
has been reported that amyloid-β protein accumulates
in the olfactory nerve in Alzheimer’s disease from its
onset.36 As Alzheimer’s is a neurodegenerative disease,the olfactory nerve is systematically damaged, followedby the hippocampal nerve. Therefore, if we can effectively stimulate the olfactory nerve in the early stages ofthe disease to promote olfactory nerve regeneration, we
may be able to prevent dementia.
Aromatherapy was administered to patients withmild Alzheimer’s disease, who showed significant improvement in cognitive function on the Gottfries-BraneSteen scale (GBS scale) (Fig. 4). From before to after (1),aromatherapy was not performed as the control period.
We conduct aromatherapy between after (1) and after (2).
In GBS-A points (cognitive function) in Alzheimer’s
disease (AD), there is no significant difference between
before and after (1), but a significant difference has beenobtained before and after (2) (P < 0.05). On the other187© 2022 Tottori University Medical Press

K. Urakami

Fig. 4. Aromatherapy improve cognitive function in Alzheimer’s disease (AD). The effects of aromatherapy on cognitive function were
examined. From before to after (1), aromatherapy is not performed as the control period. We conduct aromatherapy between after (1)and after (2). In GBS-A points (cognitive function) in AD, there is no significant difference between before and after (1), but a significant
difference has been obtained between before and after (2) (P < 0.05). On the other hand, in GBS-A points (cognitive function) in non-AD
dementia, there is no significant difference between before and after (1), and there is also no significant difference between before andafter (2). ANOVA was used for statistical analysis. AD, Alzheimer’s disease (olfactory dysfunction); non-AD dementia, non Alzheimer’s
disease dementia (no olfactory dysfunction).

hand, in GBS-A points (cognitive function) in nonAlzheimer’s disease (non-AD) dementia, there is no
significant difference between before and after (1), andthere is also no significant difference between before
and after (2). The most effective essential oil combinations were rosemary camphor and lemon for daytime
use, and genuine lavender and sweet orange for nighttime use.37 As for usage, the authors recommend using
an aroma pendant for daytime use so that the scent of
the essential oil can reach the user even if they move,and ordinary diffuser for nighttime use in the bedroom.
In an animal study using senescence-accelerated
mice (SAMP8), the above-mentioned aroma combination treatment was found to improve memory learning
ability. In biochemical experiments, both amyloid-β
protein and phosphorylated tau protein levels were significantly decreased in the hippocampus and olfactory
bulb of the aroma-treated mice.38 We found that ourrecommended combination of aromatic oils may havea useful effect on the brain pathology of Alzheimer’s
disease.
Dementia prevention is a long term process, moresimilar to running a marathon than to a 100-meter race.
Aromatherapy is easy to enjoy and can be continued fora long time; thus, it is one of the most important prevention tools.

dementia prevention is an urgent issue. I must create
useful scientific evidences and raise awareness of dementia prevention.
Acknowledgments: We would like to thank Editage (https://www.editage.jp) for the English language review.

CONFLICT OF INTEREST

The author owns patents on the forgetfulness consultation program system and the TDAS, and receives royalties from Nihon
Koden corporation.

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190© 2022 Tottori University Medical Press