Trial Outcomes & Findings for Effects of Stress-reducing Aromatherapy (NCT NCT01307748)

NCT ID: NCT01307748

Last Updated: 2019-08-19

Results Overview

Percent of baseline level of salivary cortisol (values greater than baseline indicate increased stress)

Recruitment status

COMPLETED

Study phase

PHASE2/PHASE3

Target enrollment

92 participants

Primary outcome timeframe

assessed at baseline (60 min prior to aroma exposure and stress), stress battery (30 min after aroma exposure and during stress), post-stress (60 min after completing stress battery)

Results posted on

2019-08-19

Participant Flow

212 people potentially interested in the study were evaluated for eligibility between 2010 and 2012. The potential participants were referred by clinicians from the university sleep clinic or learned about the study from the IRB-approved study information posted around the university, or published on social media.

Participant milestones

Participant milestones
Measure
Detectable Placebo Aroma: Coconut
Detectable placebo aroma:organic virgin coconut (Cocos nucifera) base oil (The Ananda Apothecary, Boulder, CO) diluted in 15 ml of grapeseed carrier oil (Now Foods, Bloomingdale, IL) and mixed until solution appeared clear. During the visit, three drops of the aroma solution were placed on a 5 x 5 mm cotton pad. The pad was then fixed to a small piece of transparent odor free tape that was attached to the participant's nose so that the pad infused with the aroma came to the midpoint between the participant's nose and upper lip. The cotton pad remained attached until the end of testing portion of the visit, but the aroma was not replenished during the testing.
Stress Reducing Aroma: Lavender
One drop (using a dropper) of organic lavender (Lavandula angustifolia) essential oil (Mountain Rose Herbs, Eugene, OR) was diluted in 15 ml of grapeseed carrier oil (Now Foods, Bloomingdale, IL). During the visit, three drops of the aroma solution were placed on a 5 x 5 mm cotton pad. The pad was then fixed to a small piece of transparent odor free tape that was attached to the participant's nose so that the pad infused with the aroma came to the midpoint between the participant's nose and upper lip. The cotton pad remained attached until the end of testing portion of the visit, but the aroma was not replenished during the testing.
Undetectable Placebo Aroma: Water
For the undetectable placebo aroma, distilled water was used to provide the appearance of essential oil while emitting no odor and producing no effects typically attributed to aromatherapy.
Overall Study
STARTED
31
31
30
Overall Study
COMPLETED
31
31
30
Overall Study
NOT COMPLETED
0
0
0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Effects of Stress-reducing Aromatherapy

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Stress Reducing Aroma
n=31 Participants
aroma with reported stress reducing effects aroma: Comparison of known stress reducing aroma to placebo aromas without stress-reducing effects
Placebo Aroma 1
n=31 Participants
aroma: Comparison of known stress reducing aroma to placebo aromas without stress-reducing effects. Coconut aroma with pleasant odor but no reported stress-reducing effects
Placebo Aroma 2
n=30 Participants
aroma: Comparison of known stress reducing aroma to placebo aromas without stress-reducing effects. Distilled water: substance with no odor or stress-reducing effects
Total
n=92 Participants
Total of all reporting groups
Age, Continuous
58.9 years
STANDARD_DEVIATION 6.6 • n=5 Participants
57.9 years
STANDARD_DEVIATION 6.0 • n=7 Participants
57.3 years
STANDARD_DEVIATION 5.9 • n=5 Participants
58.0 years
STANDARD_DEVIATION 6.0 • n=4 Participants
Sex: Female, Male
Female
24 Participants
n=5 Participants
26 Participants
n=7 Participants
23 Participants
n=5 Participants
73 Participants
n=4 Participants
Sex: Female, Male
Male
7 Participants
n=5 Participants
5 Participants
n=7 Participants
7 Participants
n=5 Participants
19 Participants
n=4 Participants
Region of Enrollment
United States
31 participants
n=5 Participants
31 participants
n=7 Participants
31 participants
n=5 Participants
92 participants
n=4 Participants

PRIMARY outcome

Timeframe: assessed at baseline (60 min prior to aroma exposure and stress), stress battery (30 min after aroma exposure and during stress), post-stress (60 min after completing stress battery)

Percent of baseline level of salivary cortisol (values greater than baseline indicate increased stress)

Outcome measures

Outcome measures
Measure
Stress Reducing Aroma:Lavender
n=31 Participants
Lavender aroma with reported stress reducing effects
Detectable Placebo Aroma: Coconut
n=31 Participants
Coconut aroma with pleasant detectable smell but without known stress-reducing effects.
Undetectable Placebo Aroma: Water
n=30 Participants
Distilled water: substance without smell or known stress-reducing effects
Percent of Baseline Level of Salivary Cortisol
post-stress
106.4 percentage of baseline cortisol level
Standard Error 70.6
187.3 percentage of baseline cortisol level
Standard Error 69.5
131.2 percentage of baseline cortisol level
Standard Error 71.9
Percent of Baseline Level of Salivary Cortisol
stress battery
170.8 percentage of baseline cortisol level
Standard Error 31.3
224.7 percentage of baseline cortisol level
Standard Error 30.8
274.7 percentage of baseline cortisol level
Standard Error 31.9

SECONDARY outcome

Timeframe: assessed at baseline (60 min prior to aroma exposure and stress), at the onset of aromatherapy exposure, stress battery (30 min after aroma exposure and during stress), post-stress (60 min after completing stress battery)

Population: All participants had EEG recordings during their visit. However, some EEG data were lost due to electrode malfunction or unusable due to presence of too much noise. The data loss was similar in all study groups.

EEG frontal asymmetry (FA) is used to assess emotional state. EEG FA processing was completed by averaging local reference EEG filtered offline from 0.1 to 70 Hz (with 60 Hz notch filter). 5-min data periods during each time were segmented into 2 seconds epochs, and the semi-automatic artifact rejection was applied. The remaining artifact-free epochs were subjected to Fast Fourier Transform (FFT) . The power spectra for individual epochs were averaged, and the measures of EEG spectral density were obtained for alpha band (8 -12.99 Hz). Square root values of power were used, and frontal hemispheric asymmetry was calculated as ((L-R)/(L+R))\*100, where L and R are square root values at the homologous left and right hemisphere sites (using local average reference values at F3 and F4). With this calculation, FA negative values reflect lower alpha power (higher activation) in the left hemisphere linked to a more positive mood. This is a unit-free measure.

Outcome measures

Outcome measures
Measure
Stress Reducing Aroma:Lavender
n=27 Participants
Lavender aroma with reported stress reducing effects
Detectable Placebo Aroma: Coconut
n=27 Participants
Coconut aroma with pleasant detectable smell but without known stress-reducing effects.
Undetectable Placebo Aroma: Water
n=27 Participants
Distilled water: substance without smell or known stress-reducing effects
Electroencephalography (EEG) Frontal Asymmetry
Aromatherapy exposure onset
.005 unitless
Standard Error .028
-.014 unitless
Standard Error .027
.064 unitless
Standard Error .029
Electroencephalography (EEG) Frontal Asymmetry
Stress battery
.031 unitless
Standard Error .027
-.001 unitless
Standard Error .026
.066 unitless
Standard Error .029
Electroencephalography (EEG) Frontal Asymmetry
Post-stress
.009 unitless
Standard Error .026
.037 unitless
Standard Error .025
.089 unitless
Standard Error .027
Electroencephalography (EEG) Frontal Asymmetry
Baseline
.013 unitless
Standard Error .027
.006 unitless
Standard Error .026
.036 unitless
Standard Error .028

SECONDARY outcome

Timeframe: Baseline (60 min prior to aroma exposure and stress), post-stress (60 min after completing stress battery)

Percent change from baseline in cognitive performance score on the Digit Span Backward (DSB) task. DSB scores range from 0 to 16, with greater scores indicative of better cognitive function. Positive change from baseline indicates better functioning.

Outcome measures

Outcome measures
Measure
Stress Reducing Aroma:Lavender
n=31 Participants
Lavender aroma with reported stress reducing effects
Detectable Placebo Aroma: Coconut
n=31 Participants
Coconut aroma with pleasant detectable smell but without known stress-reducing effects.
Undetectable Placebo Aroma: Water
n=30 Participants
Distilled water: substance without smell or known stress-reducing effects
Cognitive Performance: Percent Change From Baseline in Digit Span Backward Task Score
15.24 Percent change from baseline in DSB task
Standard Deviation 4.09
-.37 Percent change from baseline in DSB task
Standard Deviation 4.09
0.92 Percent change from baseline in DSB task
Standard Deviation 4.15

Adverse Events

Stress Reducing Aroma: Lavender

Serious events: 0 serious events
Other events: 1 other events
Deaths: 0 deaths

Detectablle Placebo Aroma: Coconut

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Undetectalbe Placebo Aroma: Water

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure
Stress Reducing Aroma: Lavender
n=31 participants at risk
Aroma with reported stress reducing effects.
Detectablle Placebo Aroma: Coconut
n=31 participants at risk
Aroma with pleasant odor but no known stress-reducing effects
Undetectalbe Placebo Aroma: Water
n=30 participants at risk
Distilled water: substance with no odor or known stress-reducing effects
Product Issues
Headache after study participation
3.2%
1/31 • Number of events 1 • The subjects actively participated in the study during one visit, approximately 4 hours in length. The adverse event data were collected for each subject during and immediately after their active study participation. The subjects were encouraged to call if they experienced any adverse events they thought might be related to the study. The overall study period of active enrollment and participation lasted between years 2010 and 2012.
0.00%
0/31 • The subjects actively participated in the study during one visit, approximately 4 hours in length. The adverse event data were collected for each subject during and immediately after their active study participation. The subjects were encouraged to call if they experienced any adverse events they thought might be related to the study. The overall study period of active enrollment and participation lasted between years 2010 and 2012.
0.00%
0/30 • The subjects actively participated in the study during one visit, approximately 4 hours in length. The adverse event data were collected for each subject during and immediately after their active study participation. The subjects were encouraged to call if they experienced any adverse events they thought might be related to the study. The overall study period of active enrollment and participation lasted between years 2010 and 2012.

Additional Information

Irina Chamine

Oregon Health & Science University

Phone: 503.577.6211

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place