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The Effects of Lavender Oil Inhalation on Emotional States, Autonomic Nervous System, and Brain Electrical Activity

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Investigate the effects of lavender oil on the central nervous system, autonomic nervous system, and mood responses in humans after inhalation. Twenty healthy volunteers participated in the experiments. The present study assessed autonomic parameters such as blood pressure, heart rate, respiratory rate, and skin temperature to determine the arousal level of the autonomic nervous system. In addition, subjects were asked to estimate their mood responses such as feeling pleasant or unpleasant, uncomfortable, sensuality, relaxation, or refreshing in order to assess subjective behavioral arousal. Finally, electroencephalogram (EEG) was recorded from 31 electrodes on the scalp according to the international 10 to 20 system, and EEG power spectra were calculated by Fast Fourier Transform (FFT). Data was analyzed by comparing the effects of lavender oil on physiological and mood states with sweet almond oil. These assessments were measured before and after using paired t-test statistical procedure. The results revealed that lavender oil caused significant decreases of blood pressure, heart rate, and skin temperature, which indicated a decrease of autonomic arousal. In terms of mood responses, the subjects in the lavender oil group categorized themselves as more active, fresher relaxed than subjects just inhaling base oil. Compared with base oil, lavender oil increased the power of theta (4-8 Hz) and alpha (8-13 Hz) brain activities. The topographic map showed obviously more scattering power in alpha range waves particularly in bilateral temporal and central area. The findings provided evidence the relaxing effect of inhaling lavender oil.
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598 J Med Assoc Thai Vol. 95 No. 4 2012
Correspondence to:
Ruangrungsi S, College of Public Health Sciences,
Chulalongkorn University, Bongkok 10300, Thailand.
Phone: 0-2218-8158
E-mail: nijsiri.r@chula.ac.th
The Effects of Lavender Oil Inhalation on Emotional States,
Autonomic Nervous System, and Brain Electrical Activity
Winai Sayorwan MPham*, Vorasith Siripornpanich MD**,
Teerut Piriyapunyaporn BSc***, Tapanee Hongratanaworakit Dr rer nat****,
Naiphinich Kotchabhakdi PhD**,***, Nijsiri Ruangrungsi PhD*
* College of Public Health Sciences, Chulalongkorn University, Bangkok, Thailand
** Research Center for Neuroscience, Institute of Molecular Biosciences,
Mahidol University, Salaya, Nakhonpathom, Thailand
*** Salaya Stem Cell Research and Development Project, Research Center for Neuroscience, Institute of Molecular Biosciences,
Mahidol University, Salaya, Nakhonpathom, Thailand
**** Faculty of Pharmacy, Srinakharinwirot University, Nakhon-nayok, Thailand
Objective: Investigate the effects of lavender oil on the central nervous system, autonomic nervous system, and mood
responses in humans after inhalation.
Material and Method: Twenty healthy volunteers participated in the experiments. The present study assessed autonomic
parameters such as blood pressure, heart rate, respiratory rate, and skin temperature to determine the arousal level of the
autonomic nervous system. In addition, subjects were asked to estimate their mood responses such as feeling pleasant or
unpleasant, uncomfortable, sensuality, relaxation, or refreshing in order to assess subjective behavioral arousal. Finally,
electroencephalogram (EEG) was recorded from 31 electrodes on the scalp according to the international 10 to 20 system,
and EEG power spectra were calculated by Fast Fourier Transform (FFT). Data was analyzed by comparing the effects of
lavender oil on physiological and mood states with sweet almond oil. These assessments were measured before and after
using paired t-test statistical procedure.
Results: The results revealed that lavender oil caused significant decreases of blood pressure, heart rate, and skin temperature,
which indicated a decrease of autonomic arousal. In terms of mood responses, the subjects in the lavender oil group
categorized themselves as more active, fresher, relaxed than subjects just inhaling base oil. Compared with base oil, lavender
oil increased the power of theta (4-8 Hz) and alpha (8-13 Hz) brain activities. The topographic map showed obviously more
scattering power in alpha range waves particularly in bilateral temporal and central area.
Conclusion: The findings provided evidence the relaxing effect of inhaling lavender oil
Keywords: Lavandula angustifolia Mill, Physiological parameters, EEG, Relaxation
Aromatherapy can be defined as the use of
essential oils to balance mind, body, and spirit. The
word is derived from two words: aroma and therapy.
“Aroma” means smell or fragrance and “therapy” means
treatment. Complementary and alternative medicines
usually use aromatherapy in their treatments by using
essential oils usually derived from volatile liquid plant
materials and other aromatic compounds from plants(1).
In Thailand, lavender is a popular essential oil in
aromatherapy and administered by inhalation or
massage. It is also the best-selling essential oil,
particularly in Bangkok(2).
Lavenders are members of a genus Lavendula
and belong to the mint family, Lamiaceae, which is
native to the Mediterranean. In general, the essential
oil of lavender (Lavendula angustifolia Mill) consists
of linalyl acetate, β-linalool, and β-caryophyllene(3).
The general properties of lavender oil are antibacterial,
antifungal, carminative (smooth muscle relaxant),
sedative, antidepressant, promoting wound healing,
and increasing the detoxification of enzymes
associated with insecticide resistance (4). A number of
researchers report the sedative effects of lavender oil
caused by the major components linalyl acetate and
β-linalool(5,6). These compounds can be rapidly
J Med Assoc Thai 2012; 95 (4): 598-606
Full text. e-Journal: http://www.jmat.mat.or.th
J Med Assoc Thai Vol. 95 No. 4 2012 599
absorbed through the body by inhalation with plasma
level reaching a maximum peak in approximately seven
minutes after administration(7), which can cause a
depression of nervous system. Linalyl acetate has a
narcotic action and linalool acts as a sedative(5,6).
Diego et al (8) found that individuals felt more relaxed
and an improved mood after inhaling lavender oil.
Moreover, an increase of mid frontal (F3, F4) alpha
power on their EEG was found after inhalation of the
oil(8). Motomura(9) suggests that lavender has been
demonstrated to decrease stress scores and increase
Theta 1 (3.5-5.5Hz) brain wave activity and decrease
Beta1 (13.5-20 Hz) which is associated with relaxation
In contrast, Masago(10) found that there was a partial
decrease in alpha1 (8-11Hz) activity and a significant
decrease in posterior temporal lobe activity after
receiving lavender oil. Some researchers studying
autonomic nervous system activity also showed
contrasting results. For example, Tongnit et al(11) found
a significantly decreased blood pressure, heart rate
and respiratory rate caused by three minutes inhalation
of lavender essential oils, whereas Sriboon(12) found
inhalation lavender oil by aroma lamp caused a
significant decrease in respiratory rate and subjective
calmness and relaxation, but diastolic blood pressure
and heart rate increased. These results might be due to
hedonic effect (pleasant and unpleasant). In the
research by Brauchli et al(13), they reported that heart
rate is an autonomic variable that can be affected by
pleasant and unpleasant oils. For example, valeric acid
(judged unpleasant) can increase heart rate, while
the heart rate decreases with phenylethyl alcohol (rated
pleasant). Therefore, the differences between stimulant
aromas and sedative aromas that can affect the pattern
of heart rate are affected by two important factors, the
characteristic of the essential oil and its pleasantness.
Many researchers studied the effect of
lavender oil on the brain wave activity, the autonomic
nervous system, and mood states(5). However, these
findings were often contradictory. Furthermore, some
studies only investigated the activities in just two
dimensions(10-12). Investigations of the effects of
lavender oil in the three dimensions of brain wave
activity, the autonomic activity, and mood responses
have rarely conducted. Consequently, the present
study seems to be the first experiment to examine
the effects of lavender on central nervous system,
autonomic nervous system, such as heart rate, blood
pressure, breathing rate, and skin temperature, and
an assessment of mood states using an inhalation
technique.
Material and Method
Subjects
Twenty selected participants equal number
of male and female aged between 18 and 35 years
(mean age 23.25 + 4.52 years) with normal body mass
indices (mean 20.86 + 1.91) were enrolled in the present
study. A summary of the demographic data of the
participants is presented in Table 1. All participants
were right-handed as determined by the Edinburgh
Handedness Inventory(14). None of the subjects had
abnormalities affecting smell, cardiovascular diseases,
or a history of smoking or drug addiction. Subjects
were screened for a normal sense of smell using the
n-butyl alcohol test method(15) (mean score10 + 0.77).
Twelve hours prior to testing subjects were asked to
wash their hair without any spray. They were also asked
not to use antiperspirants, perfumes and refrain from
consuming alcohol, cigarettes, or caffeinated drinks.
Women who were menstruating were not included
in the sample(16). They were requested to try to sleep
well before the day of the experiment to avoid
feeling fatigued or drowsy. Subjects were given a full
explanation of the research and a written informed
consent of all aspects of the present study, and were
free to withdraw at any time.
The present study was approved by the
Ethical Review Committee for Research Involving
Human Research Subjects, Health Science Group,
Chulalongkorn University, Permissions No. COA
NO.009/2011.
Essential oil administration
The oil of lavender was obtained from the
Thai China Flavours and Fragrances Company. The oil
composition was identified by gas chromatography/
mass spectrometry (GC/MS) (Thermo Finnigan
model Trace GC Ultra equipped with Finnigan DSQ
MS detector, USA).The constituent of the oil were
identified matching their mass spectra and retention
times indicated with NIST05 MS library and the
percentage compositions were computed from GC peak
Parameters n Minimum Maximum Mean SD
Age 20 18 38 23.25 4.52
Height (cm) 20 152 17 167.43 6.82
Weight (kg) 20 46 771 58.57 6.38
Body mass index 20 17.85 24.71 20.86 1.91
Smell test 20 9 11 10.00 0.77
Table1. Demographic data for the volunteers
600 J Med Assoc Thai Vol. 95 No. 4 2012
area. Two main components of lavender oil comprised
linalyl acetate (32.46%) and linalool (31.91%).
A one-milliliter mixture of either undiluted
sweet almond oil or 10% (v/v) of lavender in base oil
was delivered using an oxygen pump system through
a plastic tube via respiratory masks in an inhalation
set for adults that permitted selective routine air
flow (2 L/min). Before the experiment, they were
asked to inhale base oil and lavender oil to rate the
pleasantness of the smell on a five-point Likert scale.
The participants, who indicated oil pleasantness
within the target level range of 2-4 were chosen to
participate in the present study.
Autonomic nervous system (ANS) and mood measure-
ment
Mood state and ANS parameters, blood
pressure, heart rate, skin temperature, and respiratory
rate, were recorded at the same time. The ANS
parameters were measured using life scope 8 bedside
monitors (Nihon Kohden, Japan). The assessment of
mood state was based on the conceptual model
proposed by the Geneva Emotion and Odor Scale
(GEOS)(17). This scale described their subjective
affective feelings by a100 mm visual analog scale
based on the following five factors, pleasant feeling
(feel good), unpleasant feeling (feel bad, uncomfortable,
disgusted, frustrated, and/or stressed), sensuality
(romantic), relaxation (relax, serene, and drowsy), and
refreshing (refresh, energetic).
Electroencephalogram (EEG) recording
The set of 31 electrodes with 1 additional
ground which was placed according to the international
10-20 system at FP1, FP2,FZ, F3, F4, F7, F8, FT7, FC3,
FCZ, FC4, FT8, T3, T4, T5, T6, TP7, TP8, C3, CP3,
C4, CZ, CPZ, CP4, P3, P4, PZ, Ol, O2 and OZ. Both
mastoids would be used as the recording reference
(average of both mastoids, Al + A2/2). The electro-
oculogram (EOG) was monitored with four electrodes
placed in both external acanthi (HEOL and HEOR),
left supraorbital (VEOU) and infraorbital (VEOL)
regions. Electro-Caps are made of an elastic spandex-
type fabric with recessed, silver/silverchloride
(Ag/AgCl) electrodes attached to the fabric. Electrode
impedances were set below five kOhms(18). The
recording system is Acquire Neuroscan version 4.3
(Neurosoft, INC). The online filter was set to a band
pass with low pass is equal 70 Hz and high pass is
equal DC. A/D rate was 500 Hz. Gain was set at 19.
Notch filter was open at 50 Hz. The relative power
spectrum of the respective frequency bands derived
by Fast Fourier Transformation (FFT) were expressed
as follows: Delta (0-3.99 Hz), Theta (4-7.99 Hz), Alpha1
(8-9.99 Hz), Alpha2 (10-12.99 Hz) and Beta (13-30 Hz).
Procedure
An A-B design was used, so that each
individual session consisted of two trails. This design
was chosen because, with olfactory stimulation, the
times court of stimulatory effects is unknown, which
might make results obtained from other designs, such
as A-B-A, difficult to interpret(19). All experiments were
conducted in a quiet room with ambient temperature
(24 + 1°C) and 40 to 50% humidity. The experiments
were performed between 8.00 and 12.00 a.m. to minimize
circadian variation. All participants attended to
this research for two times, firstly, to measure the
autonomic nervous system and mood change,
secondly, to measure brain wave. Before ANS
measurement beginning, the researcher clearly
informed the procedure, then participants signed an
Informed Consent Form describing the present study
and their rights. In addition to ANS measurement,
the ANS electrodes were attached to the appropriate
positions; the ANS parameters, i.e. heart rate, skin
temperature, and respiratory rate, were recorded at
one-minute intervals. Systolic and diastolic blood
pressure was recorded every five minutes. The tests
consisted of three trials: first session served as a
base line (resting period) and took ten minutes. After
completion of the first session, subjects were asked to
rate their mood state scales. The second and third
session took 20 minutes each. In the second, the sweet
almond oil was inhaled to the subjects, then mood state
was measured after sweet almond oil inhalation. In the
third trial, 10% (v/v) lavender oil in sweet almond oil
was applied and mood state was measured after its
inhalation. Participants were required to measure their
brainwave again after the experiment no less than
seven days. The EEG experimental conditions were
the same as autonomic nervous system experiment.
The experimental procedure was divided into four
sessions of seven minutes each. Baseline EEG
recording was done with both eyes opened and eyes
closed respectively. After that participants would be
inhaled undiluted sweet almond oil. Finally, 10%
Lavender in sweet almond oil was inhaled.
Data and statistical analysis
The SPSS statistical package 17 was used
for data analysis on the effects of lavender oil on
J Med Assoc Thai Vol. 95 No. 4 2012 601
physiological and mood states in two steps before
and after treatments by a paired t-test on blood
pressure, heart rate, skin temperature, power of brain
wave and rating of mood state. The respiratory rate
was analyzed by the nonparametric Wilcoxon sign rank
test. A p-value < 0.05 was considered significant.
Mann Whitney U-test was performed to determine the
gender different of physiological and mood effect.
Results
Autonomic nervous system parameters
The mean and Standard Deviation (SD)
values of autonomic parameters in the experiment
are presented in Table 2. The data were compared on
various autonomic parameters during resting and
inhaling sweet almond oil. Subjects had significantly
decreased heart and breathing rates (p-value < 0.05)
during the sweet almond oil treatment compared
with those of resting. Moreover, when subjects
inhaled the lavender the systolic and diastolic blood
pressures, heart rate and skin temperature were
significantly decreased compared with sweet almond
oil inhalation.
Mood state response
The mean and SD of mood state response
are shown in Table 3. Subjects felt unpleasant when
sweet almond oil was applied, with data showing
decreased scores in good, active, fresh and relaxed
feelings. After a lavender inhalation, subjects felt they
had significant increases in pleasant emotions; good,
active, fresh, and relaxed (p-value < 0.05). Furthermore,
Parameters n Rest SO LO p-value p-value
rest and SO SO and LO
Mean SD Mean SD Mean SD (t-test) (t-test)
Systolic blood pressure (mmHg) 20 109.91 9.74 110.27 9.51 108.00 8.41 0.588 <0.001*
Diastolic blood pressure (mmHg) 20 69.32 8.76 70.26 8.96 68.52 8.43 0.527 <0.001*
Heart rate (bpm) 20 71.20 11.69 68.43 12.86 65.68 10.73 0.001* <0.001*
Skin temperature (°C) 20 31.14 1.64 31.25 1.96 31.00 1.94 0.296 0.001*
Respiratory rate (bpm) 20 18.44 9.34 15.70 2.91 16.36 6.71 0.029* 0.148
* Significant difference, p-value < 0.05
SO = sweet almond oil; LO = lavender oil
Table 2. Mean and SD of ANS parameter change during resting, sweet almond oil and lavender
Emotion n Rest SO LO p-value p-value
rest and SO SO and LO
Mean SD Mean SD Mean SD (t-test) (t-test)
Good 20 61.50 11.20 50.05 17.22 73.15 14.78 0.010* <0.001*
Bad 20 15.50 12.77 23.55 18.57 15.12 18.71 0.046* 0.085
Active 20 50.80 16.18 44.05 13.83 64.20 13.66 0.104 <0.001*
Drowsy 20 26.55 19.47 40.90 24.47 30.05 20.22 0.003* 0.047*
Fresh 20 53.45 12.68 43.35 11.12 59.40 18.18 0.004* 0.001*
Relax 20 59.15 20.97 51.55 19.26 73.65 21.41 0.243 0.004*
Stress 20 12.55 8.75 16.25 12.38 16.45 11.35 0.086 0.948
Uncomfortable 20 16.85 13.45 24.00 16.94 18.70 15.22 0.627 0.206
Romantic 20 28.78 17.43 31.35 22.86 40.55 24.38 0.709 0.151
Frustrated 20 12.51 10.15 16.40 14.77 16.55 18.38 0.094 0.976
Clam 20 62.00 18.96 54.85 19.98 61.60 20.18 0.112 0.276
Disgust 20 8.60 7.60 12.35 11.60 10.85 14.11 0.092 0.712
* Significant difference, p-value < 0.05
SO = sweet almond oil; LO = lavender oil
Table 3. Mean and SD of emotional state change during resting, sweet almond oil and lavender
602 J Med Assoc Thai Vol. 95 No. 4 2012
the bad and drowsy feelings were significantly
decreased (p-value <0.05).
EEG data
The EEG power was calculated for each
frequency band among resting, sweet almond oil,
and lavender oil inhalation. The studied areas were
divided into the left anterior (Fp1, F3, F7), right anterior
(Fp2, F4, F8), right posterior (P4, T6, O2), left posterior
(P3, T5, O1), and middle (Fcz, Cz, Cpz) (20) shown each
band power with theta, alpha1, alpha2, Beta (Table 4)
and expressed by topographic maps in Fig. 1. There
were noticeable changes of band power in theta and
alpha waves that significantly increased during the
lavender inhalation in all brains areas (p-value <0.05).
However, band powers in beta waves were not
significantly different (p-value > 0.05, data not shown).
The present study examined changes in the anterior,
posterior alpha asymmetry (left and right side) response
to sweet almond oil and lavender. There was no
significant asymmetry (p-value > 0.05) as Fig. 1. The
topographic map shows obviously more scattering
power in alpha brain, particularly in bilateral temporal
and central area after smelling lavender compared
with resting and sweet almond oil as shown in Fig. 2.
The analysis of male and female groups
Mean different score of autonomic nervous
system, mood state and power of brain during lavender
oil inhalation when compare to sweet almond oil from
10 male and 10 female group demonstrated that there
were no significant change observed between both
gender groups (p-value > 0.05, data not shown).
Discussion
In the present research, lavender oil was
administered by inhalation to healthy subjects. Brain
wave activity and ANS parameters (blood pressure,
Area Eye close (n = 20) SO (n = 20) LO (n = 20) p-value p-value
mean mean mean eye close and SO SO and LO
(t-test) (t-test)
Theta power (μV2)
Left anterior 1.91 1.54 2.16 0.590 0.001*
Right anterior 2.00 1.62 2.27 0.090 0.001*
Center 2.68 2.10 3.05 0.030* 0.006*
Left posterior 1.13 1.08 1.34 0.550 0.002*
Right posterior 1.15 1.10 1.38 0.025* 0.025*
Alpha1 power (μV2)
Left anterior 3.44 3.71 6.94 0.218 0.001*
Right anterior 4.02 4.38 7.70 0.218 0.001*
Center 4.78 4.83 9.40 0.156 0.001*
Left posterior 4.16 4.56 6.86 0.218 0.001*
Right posterior 4.29 4.46 8.79 0.001* 0.001*
Alpha2 power (μV2)
Left anterior 1.51 1.43 2.09 0.911 0.011*
Right anterior 1.63 1.50 2.23 0.575 0.006*
Center 2.28 1.96 3.09 0.179 0.003*
Left posterior 2.37 2.31 3.41 0.823 0.008*
Right posterior 2.76 2.51 4.10 0.002* 0.002*
Beta power (μV2)
Left anterior 0.31 0.35 0.33 0.167 0.351
Right anterior 0.32 0.36 0.35 0.156 0.433
Center 0.36 0.41 0.41 0.086 0.627
Left posterior 0.31 0.37 0.36 0.156 0.852
Right posterior 0.31 0.36 0.37 0.794 0.794
* Significant difference, p-value < 0.05
SO = sweet almond oil; LO = lavender oil
Table 4. Mean power values in eyes closed during sweet almond oil and lavender
J Med Assoc Thai Vol. 95 No. 4 2012 603
heart rate, respiratory rate and skin temperature) were
recorded as indicators of the arousal level of the
nervous system. In addition, subjects had to rate their
mood state in terms of good, bad, active, drowsy, fresh,
relaxed, stressed, uncomfortable, romantic, frustrated,
calm, and disgusted in order to assess subjective
behavioral arousal.
Inhalation of lavender oil significantly
decreased the level of ANS arousal, namely, decreases
of blood pressure, heart rate, and skin temperature.
These changes of the ANS parameters represent the
function of parasympathetic nervous system that
counteracts the function of sympathetic nervous
system. As for mood states, subjects felt better, fresher,
more active, more relaxed, and less drowsy. This finding
points towards a decrease of arousal as assessed
through subjective self-evaluation. The results of the
present study support previous studies indicating
lavender odor can influence relaxing
Previous studies using a footbath containing
lavender oil also supports the positive effects on the
parasympathetic neural activity of lavender oil(21). To
study the underlying mechanism of lavender oil on the
nervous system, its main component, linalool, is used
as a compound to study its effects compared with
plain lavender oil. It is noteworthy that Heuberger
et al(22) found the reduction of blood pressure and
skin temperature after applying linalool to the skin of
participants. In addition, linalool has a lot of isoforms
in nature such as R)-()-, (S)-(+)- and (RS)-(+)- forms.
One study using R-()-linalool found similar effects
from this compound on the autonomic nervous
system parameters and also promoted calming and
feelings of vigor(23). According to the pharmacokinetic
properties of linalool, Yamada(24) was able to show the
lipophilic properties of the linalool was suitable for
transporting this compound across the blood-brain
barrier. When reaching the brain, linalool can bind
with the GABA (gamma aminobutyric acid) receptors
similar to the benzodiazepines and caused relaxing
and sedative effects. In one study, they found linalool
could potentiate the effects of GABA, the main
inhibitor neurotransmitters of the human brain in the
amygdala, the subcortical brain area involved in the
emotional response to the environment(25). The effect
of linalool on the amygdala may explain the mood
effects of lavender.
It is felt the effects of lavender inhalation on
the brain wave activities are well demonstrated in the
present study. During inhalation with lavender, the
power of theta (4-8 Hz) and alpha (8-13 Hz) activities
are significantly increased in all brain regions. This
result is consistent with the study of Diego(8) that
found after lavender inhalation that frontal alpha
power was significantly increased. Furthermore,
a study conducted at the University of Occupational
and Environmental Health, Kitakyushu Japan(26) used
changes of electroencephalogram (EEG) to measure
the effects of aromas. The present study found
relaxing effects with increases of alpha wave activities
after administering lavender, cineol sandalwood, and
alpha-pinene. The EEG evidence of relaxation can be
seen in various practices such as meditation.
Meditation is a way of balancing the body and the
mind as well as controlling the mind to experience
feelings of peace and relaxation. The study among
people meditating can demonstrate similar EEG
changes with lavender inhalation, which presented as
an increase in theta and alpha activities in the brain
during meditation(27). The increase in theta and alpha
activities can also be observed even during pre-
meditation states in people who frequently practice
meditation(28). These results lend support that increases
in theta and alpha wave activity causes a range of
Fig. 2 Brain Topographical map of the distribution of
alpha brainwave activity. The red areas indicate a
significantly increase of power in bilateral temporal
and central area during inhalation of lavender
Fig. 1 The power of alpha activity showed no significantly
different between left and right side of the brain
604 J Med Assoc Thai Vol. 95 No. 4 2012
general relaxation effects and can be induced by a
range of chemical and non-chemical techniques(29).
The changes in physiological and mood state
were not significant between males and females group.
This might be the effect of control pleasantness of
subjects before experiment. According to previous
studies, the hedonic impact produced effects on the
autonomic nervous system. However, to reduce
hedonic impact bias, the participants were initially
selected by measuring the degree of liking of each
essential oil. They were asked to inhale base oil and
lavender oil and to rate the pleasantness of the smell
on a five-point Likert scale. The participants, who
indicated odor pleasantness within the target level
range of 2-4, were chosen to participate in the present
study. The present study is relevant because previous
research found that a significant change for left
frontal differences in EEG were associated with the
pleasant smells. By contrast, the unpleasant smells can
also affect the brain on the right side (30). There was
no difference in EEG between left and right side when
feeling neutral to smells. Thus, according to the above
studies, they suggested that the odor liking should be
evaluated before the experiment, which could reduce
the bias from the hedonic effect.
Conclusion
In conclusion, the present study explored the
relaxing effects of inhaling lavender oil. The findings
provided evidence that brain wave activity, autonomic
nervous system response, and mood states were
affected by lavender oil. The results lend some support
for including lavender odor in medications aimed at
blood pressure reduction and relieving depression or
stress. For example, lavender oil decreases level of
anxiety and improves mood in dental clinics(31), after
insomnia, women inhale lavender oil significantly
improvement in sleep quality(32).
Acknowledgement
The authors wish to thank THE 90th
Anniversary of Chulalonggkorn University Fund
(Ratchadaphiseksomphot Endowment Fund) and
Herbal Remedies and Alternative Medicine Task
Force of STAR: Special Task Force for Activating
Research under 100 years Chulalongkorn University
fund for the research grant supporting the present
study. The authors wish to thank Dr. Chanida
Palanuvej and Miss Thidarat Duangyod for GCMS
protocol recommend and Dr. David Roberts for his
editorial corrections.
Potential conflicts of interest
None.
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ผลของการสดดมนำมนลาเวนเดอร์ต่ออารมณความรู้สึก การทำงานของระบบประสาทอตโนมัติ
และคลื่นไฟฟาสมอง
วินัย สยอวรรณ, วรสิทธิ์ ศิริพรพาณิชย์, ธีรัช พิริยะปัญญาพร, ฐาปนีย์ หงส์รัตนาวรกิจ, นัยพินิจ คชภักดี,
นิจศิริ เรองรงษ
วัตถุประสงค์: เพื่อทดสอบผลของน้ำมันลาเวนเดอร์ที่มีต่อระบบประสาทซึ่งแบ่งเป็นประสาทส่วนกลาง และประสาท
ส่วนอัตโนมัติ และการตอบสนองของอารมณ์ความรู้สึกหลังจากการสูดดม
วัสดุและวิธีการ: การศึกษาครั้งนี้อาสาสมัครสุขภาพดีจำนวน 20 คน การศึกษาครั้งนี้ทดสอบการเปลี่ยนแปลง
ในระบบประสาทอัตโนมัติโดยศึกษาการเปลี่ยนแปลง ของความดันโลหิต, การเต้นของหัวใจ อัตราการหายใจ และ
อุณหภูมิที่ผิวหนัง นอกจากนี้ยังศกษาอารมณความรู้สึกโดยแบงเปนดาน ไดแก ความชอบในกลิ่น, ความไมชอบในกลิ่น
ความดงดดทางเพศ การผอนคลาย และความสดชื่น ในระบบประสาทสวนกลางมการศกษาการเปลี่ยนของคลื่นสมอง
โดยบันทึกคลื่นสมองทั้งหมด 31 จุดทั่วศีรษะ โดยบันทึกข้อมูลทั้งความถี่และค่าฟูเรียร์ทรานส์ฟอร์มอย่างเร
ซึ่งข้อมูลเปรียบเทียบผลการเปลี่ยนแปลงทางสรีรวิทยา และอารมณ์ความรู้สึกเมื่อสูดดม น้ำมันลาเวนเดอร เทียบกับ
สูดดมนำมนอลมอนด โดยใชสถิติ paired t-test
ผลการศึกษา: กลิ่นลาเวนเดอร์ทำให้ ความดันโลหิต การเต้นของหัวใจ และอุณหภูมิที่ผิวหนังลดลงเป็นการแสดงถึง
การลดการทำงานของระบบประสาทอัตโนมัติ ในส่วนของอารมณ์ความรู้สึกอาสาสมัคร รู้สึกว่าตนเองมีความรู้สึก
กระตอรอร้น รู้สึกสดชื่น และผอนคลายมากกวาดมกลิ่นนำมนอลมอนด นอกจากนี้ยังพบว่า มีการเพิ่มของคลื่นสมอง
ประเภทธีต้า และแอลฟาอยางเหนได้ชัดเจน จากภาพถายคลื่นสมองพบวาสมองสวน temporal และ central แอลฟา
เพิ่มขึ้น
สรุป: ผลการศึกษาครั้งนี้สนับสนุนผลการการผ่อนคลายของการสูดดมน้ำมันลาเวนเดอร
... In recent years, many scientific studies have been conducted to investigate the effects of aroma inhalation on human brain function. The psychophysiological changes induced by fragrance inhalation have been evaluated using various methods such as electroencephalography (EEG), near-infrared spectroscopy, and functional magnetic resonance imaging [10,13,14]. ...
... This method records electrophysiological signals generated by brain activity by attaching a sensor to the surface of the scalp. The electrical signals mentioned correspond to the following frequency bands: delta (0-4 Hz), theta (4-8 Hz), alpha (8)(9)(10)(11)(12) and beta (12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30). Human actions, thoughts, and emotions can alter the brain wave activity at different frequencies. ...
... This method records electrophysiological signals generated by brain activity by attaching a sensor to the surface of the scalp. The electrical signals mentioned correspond to the following frequency bands: delta (0-4 Hz), theta (4-8 Hz), alpha (8-12 Hz) and beta (12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30). Human actions, thoughts, and emotions can alter the brain wave activity at different frequencies. ...
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This study investigated the effects of olfactory stimulation with aroma oils on the psychophysiological responses in women. Ten aromatic oils (lavender, rosemary, rose, eucalyptus, jasmine, geranium, chamomile, clary sage, thyme, and peppermint) were used on 23 women aged between 20 and 60 years. They inhaled the scent for 90 s through a glass funnel attached to their lab apron, 10 cm below their nose, while the pump was activated. Electroencephalography, blood pressure, and pulse rate were measured before and during inhalation of the aroma oils. The relative alpha (RA) power spectrums indicating relaxation and resting state of the brain significantly increased when lavender, rosemary, eucalyptus, jasmine, chamomile, clary sage, and thyme oils were inhaled compared to those of before olfactory stimulation. The ratio of alpha to high beta (RAHB), an indicator of brain stability and relaxation, significantly increased when rosemary, jasmine, clary sage, and peppermint oils were inhaled. The relative low beta (RLB) power spectrum, an indicator of brain activity in the absence of stress, significantly increased when stimulated with lavender, rosemary, rose, and geranium scents. Further, systolic blood pressure significantly decreased after introduction of all 10 types of aromatic oils, which indicates stress reduction. Thus, olfactory stimulation with aroma oil had a stabilizing effect on the prefrontal cortex and brain activity and decreased systolic blood pressure.
... Lavender (Lavandula angustifolia) oil (LO) is an antispasmodic, anticonvulsant, antidepressant, painkilling, and carminative substance used to treat various conditions [3,4]. It also accelerates burn healing by modulating inflammatory reactions [5,6] and has antibacterial and antifungal properties [7]. With so many benefits, LO has been investigated as a natural medicinal extract to improve biomedical therapies and quality of life [5,6,[8][9][10][11]. ...
... It also accelerates burn healing by modulating inflammatory reactions [5,6] and has antibacterial and antifungal properties [7]. With so many benefits, LO has been investigated as a natural medicinal extract to improve biomedical therapies and quality of life [5,6,[8][9][10][11]. ...
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Full-text available
(1) Background: Essential oils have long been used as therapeutic agents. Lavender (Lavandula angustifolia) oil (LO) is an antispasmodic, anticonvulsant, relaxant, painkilling, and antimicrobial essential oil investigated as a natural substance for biomedical therapies. Nanoparticles have shown significant promise in improving drug delivery and efficacy. Considering these benefits, the aim of this study was to evaluate the toxicity of LO and lavender oil niosomes (LONs) in stem cells and myofibroblast models cultured in vitro. (2) Methods: Adipose tissue-derived stem cells and myometrial cells were cultured with LO or LONs at different concentrations (0, 0.016%, 0.031%, and 0.063%) and toxicity was evaluated with PrestoBlue™ and live/dead assay using calcein and ethidium homodimer. (3) Results: Cell viability was similar to controls in all groups, except in 0.063% LO for myometrial cells, which showed lower viability than the control medium. (4) Conclusion: These results suggest that both LO and LONs are safe for cell culture and may be used for pharmaceutical and biomedical therapies in future applications in regenerative medicine. View Full-Text
... Regarding olfactory stimuli, the majority of studies used lavender oil to reduce responsive behaviours. Lavender has a long history of medical use and has been employed for its sedative and calming properties (Cavanagh & Wilkinson, 2002;Sayorwan et al., 2012). Although it has been widely used in olfactory stimulation, specific pharmacological effects of lavender aromatherapy are difficult to distinguish from any innate or learned preference for this scent (Bradley et al., 2009). ...
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There is a growing interest in using olfactory (smell) stimulation in dementia care. This study aims to extend current knowledge by synthesising the evidence on the efficacy of interventions using olfactory stimulation for people with dementia and to assess the effects of different types of odours and administration methods using a mixed methods approach. The rapid review was conducted based on searches in six electronic databases. A narrative approach was applied to assess 20 studies included in the review. Fourteen studies used a quasi-experimental design, five studies used an experimental design and one was a case study. High heterogeneity was found on odours and methods of application used, with the majority of studies administering lavender oil using a diffuser. Mixed results were reported on the benefits of olfactory stimulation on responsive behaviours and cognitive function. Although the evidence available is limited, encouraging results were found regarding olfactory stimulation and increased sleep duration, food intake and improved balance. It was not possible to draw any overall conclusion in relation to the effect of olfactory stimulation. However, this review shows promising results that support further investigation of olfactory stimulation as a nonpharmacological intervention for people with dementia. The review is limited due to the low to moderate quality of studies included. Furthermore, the broad range of approaches was employed, and comparison between the studies was difficult. Further high-quality mixed method studies using robust and detailed protocols are needed to clarify the effects of olfactory stimuli and any other factors that may influence the responses of people with dementia.
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A 3-arm, parallel group, randomized clinical trial examines the effect of aromatherapy through inhalation and foot massage on blood pressure and stress response in patients with essential hypertension. Lavender oil reduced blood pressure, heart rate, serum cortisol, and subjective anxiety in hypertensive patients.
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The available evidence on dogs’ scent preferences is quite limited. The purpose of this study was to verify the canine response to selected odors that may also be preferred by humans. The experiment was performed using 14 adult dogs (10 female and 4 male) of different breeds, body size, and age (1–14 years). During the experiment, dogs were exposed to 33 odor samples: a neutral sample containing pure dipropylene glycol (control) and 32 samples containing dipropylene glycol and fragrance oils. The dog was brought to the experimental area by its handler, who then stopped at the entrance, unleashed the dog, and remained in the starting position. The dog freely explored the area for 30 s. All dog movements and behavior were recorded and analyzed. The methodology of observing the dogs freely exploring the experimental area allowed us to determine the smells that were the most attractive to them (food, beaver clothing). Our study shows that dogs interacted more frequently with the scents of blueberries, blackberries, mint, rose, lavender, and linalol.
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Mood disorders, also often referred to as affective disorders, are a group of psychiatric illnesses that severely impact mood and its related functions. The high medical expenditures have placed a significant financial burden on patients and their families. Aromatherapy is an alternative and complementary treatment that utilizes essential oils (EOs) or volatile oils (VOs) to achieve major therapeutic goals. In general, EOs are volatile chemicals that enter the body primarily through skin absorption and/or nasal inhalation. In addition, they can work through oral administration. Inhalation aromatherapy has shown unique advantages for treating mood disorders, especially depression, anxiety and mental disorders such as sleep disorder, which have been validated over the last decade through clinical and animal studies. Accumulating evidence has shown that EOs or VOs can bypass the blood-brain barrier to target brain tissue through the nasal-brain pathway. Subsequently, they act on the cerebral cortex, thalamus, and limbic system in the brain to improve symptoms of anxiety, depression and improve sleep quality. Here, we review the natural aromatic plants’ volatiles or essential oils used commonly as adjuncts to manage mood disorders and illustrate the mechanisms of inhalation aromatherapy, and mainly summarized the application of transnasal inhalation aromatherapy in depression, anxiety, and sleep disorders. We conclude that aromatherapy does not cause side-effects, which is vastly different from commonly used psychotropic drugs. Inhalation aromatherapy via brain-targeted nasal delivery offers potentially efficacious treatment for mental disorders and merits further study.
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Purpose: This study evaluated the effects of the mixed essential oils containing sweet orange, lavender, and amyris (MEO) on human electroencephalogram (EEG) activity.Methods: EEG activity was recorded by examining the sequence of brain waves of 20 adults, aged from 20 to 30, before and during inhaling the mixed essential oils.Results: MEO showed activity centered on the frontal lobe, which is responsible for higher-order functions against external stimuli, and this result indicated that the oils acted as an intellectual effect. Additional experiments showed that the brain was relaxed and stabilized through a decrease in the absolute slow alpha (ASA) and the relative slow alpha (RSA), a decrease in the absolute beta (AB) and the absolute high beta (AHB), and an increase in the spectral edge frequency 50% of alpha (ASEF), respectively. Also, the oils induced the awakening states of the brain with a decrease in the absolute alpha (AA) and the absolute theta (AT), and increase of the spectral edge frequency 50% (SEF50). Furthermore, it was possible to confirm the state of brain immersion through the increase in the absolute fast alpha (AFA), relative fast alpha (RFA), relative mid beta (RMB), ratio of mid beta to theta (RMT), ratio of SMR to theta (RSMT), relative gamma (RG) and the spectral edge frequency 90% (SEF90).Conclusion: Taken together, these results suggest that the inhaling of MEO affect the brain to be a good condition and improves its concentration ability.
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Lavender essential oil is popular as a complementary medicine in its own right and as an additive to many over the counter complementary medicine and cosmetic products¹⁻³. Indeed, products derived from the popular garden herb Lavender (Lavandula spp.) have been used for centuries as a therapeutic agent, with the more ’recent’ addition, the essential oils derived from these plants, being widely used as an antibacterial in World War I1,4. The oil is traditionally believed to have sedative, carminative, anti-depressive and antiinflammatory properties, in addition to its recognised antimicrobial effects. Many of the activities attributed to lavender oil have not, however, been substantiated in the scientific literature. This is further complicated by the fact that the majority of research into lavender essential oils has been based on oil derived from English lavender (Lavandula angustifolia), with little or no differentiation being made between this and other lavender essential oils. The therapeutic potential of essential oils produced from other varieties, such as L. x intermedia (lavandin), L. stoechas (French lavender) and L. x allardii, have largely been ignored. Although the ethnobotanical uses and major chemical constituents are similar between various lavenders, some differences do occur in both oil composition and in the reported therapeutic uses for different species3,5. The significant scientific interest in recent years into the validity/veracity of the traditional beliefs surrounding lavender oil and their scientific basis, if any, was recently reviewed by Cavanagh & Wilkinson³. In this paper we provide an overview of the use of lavender oil in infectious disease and an update on recent research on alternative uses of lavender oil.
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The objective of this study is to determine the effects of 12 weeks of lavender aromatherapy on self-reported sleep and heart rate variability (HRV) in the midlife women with insomnia. Sixty-seven women aged 45-55 years, with a CPSQI (Chinese version of Pittsburgh Sleep Quality Index) greater than 5, were recruited from communities in Taiwan. The experimental group (n = 34) received lavender inhalation, 20 min each time, twice per week, for 12 weeks, with a total of 24 times. The control group (n = 33) received health education program for sleep hygiene with no intervention. The study of HRV was analyzed by time- and frequency-domain methods. Significant decrease in mean heart rate (HR) and increases in SDNN (standard deviation of the normal-to-normal (NN) intervals), RMSDD (square root of the mean squared differences of successive NN intervals), and HF (high frequency) of spectral powers analysis after lavender inhalation were observed in the 4th and 12th weeks of aromatherapy. The total CPSQI score of study subjects was significantly decreased in the experimental group (P < 0.001), while no significant difference was observed across the same time period (P = 0.776) in the control group. Resting HR and HRV measurements at baseline 1 month and 3 months after allocation showed no significant difference between the experimental and control groups. The study demonstrated that lavender inhalation may have a persistent short-term effect on HRV with an increase in parasympathetic modulation. Women receiving aromatherapy experienced a significant improvement in sleep quality after intervention. However, lavender aromatherapy does not appear to confer benefit on HRV in the long-term followup.
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To evaluate the effect of the odor of incense on brain activity, electroencephalograms (EEGs) and event-related potentials (ERPs) in a push/wait paradigm were recorded in 10 healthy adults (aged 23-39 years) with normal olfactory function. EEG was recorded from 21 electrodes on the scalp, according to the International 10-20 system, and EEG power spectra were calculated by fast Fourier transform for 3 min before and during odor presentation. ERPs were recorded from 15 electrodes on the scalp before, during and after exposure to incense with intervals of 10 min. In a push/wait paradigm, two Japanese words, 'push' as the go stimulus and 'wait' as the no-go stimulus, appeared randomly on a CRT screen with equal probability. The subjects were instructed to push a button whenever the 'push' signal appeared. Fast alpha activity (10-13 Hz) increased significantly in bilateral posterior regions during incense exposure compared to that during rose oil exposure. The peak amplitudes of no-go P3 at Fz and Cz were significantly greater during incense inhalation. The latencies of go P3 and no-go P3, and the amplitude and latencies of no-go N2 did not change by exposure to the odors of both incense, rose and odorless air. These results suggest that the odor of incense may enhance cortical activities and the function of inhibitory processing of motor response.
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Two studies were conducted to examine the nature of the verbal labels that describe emotional effects elicited by odors. In Study 1, a list of terms selected for their relevance to describe affective feelings induced by odors was assessed while participants were exposed to a set of odorant samples. The data were submitted to a series of exploratory factor analyses to 1) reduce the set of variables to a smaller set of summary scales and 2) get a preliminary sense of the differentiation of affective feelings elicited by odors. The goal of Study 2 was to replicate the findings of Study 1 with a larger sample of odorant samples and participants and to validate the preliminary model obtained in Study 1 by using confirmatory factor analysis. Overall, the findings point to a structure of affective responses to odors that differs from the classical taxonomies of emotion such as posited by discrete or bidimensional emotion theories. These findings suggest that the subjective affective experiences or feelings induced by odors are structured around a small group of dimensions that reflect the role of olfaction in well-being, social interaction, danger prevention, arousal or relaxation sensations, and conscious recollection of emotional memories.
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Objectives:This study was designed to investigate the effect of foot-bath with or without the essential oil of lavender on the autonomic nervous system. Design: Randomized crossover controlled study. Setting: Nursing college, Nagano, Japan. Intervention:Young women sat with their feet soaked in hot water for 10 minutes with and without the essential oil. Outcome measures:An electrocardiogram, finger tip blood now and respiratory rate were recorded,Autonomic function was evaluated using spectral analysis of heart rate variability. Results:The foot-bath caused no changes in heart or respiratory rates, but produced a significant increase in blood now. Using spectral analysis, the parasympathetic nerve activity increased significantly during the both types of foot-bath. In the case of the foot-bath with the addition of essential oil of lavender, there were delayed changes to the balance of autonomic activity in the direction associated with relaxation. Conclusion:A hot foot-bath and oil of lavender appear to be associated with small but significant changes in autonomic activity. (C) 2000 Harcourt Publishers Ltd.
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The aim of the study was to find correlations between changes in olfactory sensitivity and the menstrual cycle. 14 young, healthy volunteers participated in the experiments. Subjects menstruated regularly and did not use oral contraceptives. Three odorants were investigated: phenylethyl alcohol, androstenone, and nicotine. Dilution series of the odorants were prepared, and presented to the subjects in order to determine the detection thresholds (triple forced choice). Additionally, the subjects' hedonic estimates of the odorants were measured, and mood states as well as hormonal levels of LH and estrogen were determined. Before the actual experiments started, subjects participated in three training sessions. One experiment was subdivided into 5 phases (two pre- and two postovulatory phases; one ovulatory phase). Only with regard to androstenone did trend analyses reveal a significant quadratic relationship between hedonic estimates and phases of the menstrual cycle, peaking at ovulation. Olfactory sensitivity was not significantly influenced by the menstrual cycle.
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Assessment of olfactory functioning at the CCCRC entails a threshold test and an odor identification test that contains eight everyday items. A performance average on the two tests yields a composite score on a scale from 0 (anosmia) to 7 (normosmia). The performance of normal volunteers is stable over most of an individual's life span, but decreases for persons over the age of 65 years. Approximately half the patients with olfactory complaints display anosmia, and the other half have hyposmia. The distribution of scores, however, varies with etiologic category, emplified by the fact that patients with nasal/sinus disease display anosmia more frequently than hyposmia. The tests can determine cause (e.g., improvement of score with corticosteroid treatment in cases of nasal/sinus disease) and can also assess degree of improvement with treatment, such as sinus operation.
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In the present experiment, we found that inhaling lavender oil vapour blocked pentetrazol- and nicotine-induced convulsion and electroshock convulsion in mice.