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Essential Oil Aroma, Subjective Stress, and Diurnal Cortisol Secretion in Healthy Adults: A Single Blind, Placebo Controlled, Cross-over Study

The IFA appointed Northumbria University to undertake three studies on behalf of the IFA to determine whether essential oils can reduce stress levels within people using saliva and hair samples to determine cortisol, therefore stress levels. Previous studies on essential oils have not kept the essential oil active, subjecting it to oxygen and sunlight which quickly kills the active ingredients, so results are not accurate. That is until now. The IFA through its years of essential oil knowledge created a blend using five of the top known essential oils that are ‘known’ to decrease stress and we wanted to see if this information was correct using scientific research methods.

The first study assessed the impact of sniffing the aroma of this essential oil blend on the stress hormone cortisol and participant evaluations of perceived stress, wellbeing, and mood were undertaken. Volunteers were recruited by Northumbria University and saliva samples taken before they sniffed the oil daily and after they inhaled the oil in the laboratory. The study was conducted over an eight-week period during which time 2400 salivary cortisol samples were collected and assessed to test the effectiveness of the aroma on this biological marker of stress over the course of the study. Cortisol levels were compared to those collected from the same individuals over a similar duration when they were not being exposed to the aroma. Weekly completion of the subjective assessments of stress and mood allowed comparison of the perceived effectiveness of the aroma, and evaluation of the correlation between biological and subjective measures. 

The results of this study are now available and we are delighted to say the results were positive. Click here for more details. ARROWS.png

The second and third studies took an alternative practice focused approach. 

In study 2 practitioners of the IFA recruited clients to assess the impact of traditionally extracted essential oils on cortisol over an eight-week treatment period. To avoid the need for practitioners and clients to collect saliva they took hair cortisol samples. The study was conducted over an eight-week period during which time 2400 hair samples were collected and assessed to test the effectiveness of the aroma on the biological marker of stress over the course of the study. Samples of hair were cut close to the scalp from clients on the first and last day of treatment. These allowed analysis of the cortisol levels in the weeks leading up to treatment and the effect of treatment over the eight-week period. Weekly subjective assessments were also made using the university’s online system that allowed questionnaires to be completed quickly using a smartphone. The results will be compared to those from a sample of individuals not in treatment and recruited by the university over the same period. 

Study 3 followed the same approach as study 2 but evaluated CO2 extracted essential oils. 

Taken together studies 2 and 3 will allow for the relative effectiveness of the two sources of essential oils to be compared, as well as comparing them to no treatment. 

The aim of this program of research was to establish a strong scientific indication of the effectiveness of essential oil aromas on stress by employing a rigorous scientific method and validated measures. The IFA undertook this pioneering research of comparing CO2 and traditionally obtained essential oils to show for the first time if there is indeed, if any, difference on a given set of symptoms (in this case stress) between the two. There has never been any research before that has employed such rigorous scientific measures to determine the efficacy of essential oils. The impact on our industry will be huge. For the first time, research will not be just anecdotal but scientifically proved helping alleviate aromatherapy from the doldrums of just being a relaxing therapy to one of real medical benefits.

The results from studies 2 and 3 will be available in mid-2024.

In previous years the IFA has funded and conducted research projects in aromatherapy and endometriosis and a rheumatoid arthritis research trial at the Royal Masonic Hospital with positive results.