Aromatherapy and Essential Oils (PDQ®): Complementary and alternative medicine - Health Professional Information [NCI] - Human / Clinical Studies
A placebo-controlled, double-blind, randomized trial conducted in Australia investigated the effects of inhalation aromatherapy on anxiety during radiation therapy. A total of 313 patients receiving radiation therapy were randomly assigned to one of three groups: carrier oil with fractionated oils, carrier oil only, or pure essential oils of lavender, bergamot (Citrus aurantium L. ssp. bergamia [Risso] Wright & Arn. [Rutaceae]; [synonym: Citrus bergamia Risso]), and cedarwood (Cedrus atlantica [Endl.] Manetti ex Carriere [Pinaceae]). All three groups received the oils by inhalation during their radiation therapy. The authors reported no significant differences in depression (as measured by HADS) or psychological effects (as measured by the Somatic and Psychological Health Report) between the groups. The group that received only the carrier oil showed a statistically significant decrease in anxiety (as measured by HADS) compared with the other two groups.
Another randomized controlled trial investigated the effects of massage or aromatherapy massage in 103 cancer patients who were randomly assigned to receive massage using a carrier oil (massage group) or massage using a carrier oil plus the Roman chamomile essential oil (Chamaemelum nobile [L.] All. [synonym: Anthemis nobilis L.]) (aromatherapy massage group). Two weeks after the massage, the authors found a statistically significant reduction in anxiety in the aromatherapy massage group (as measured by the State-Trait Anxiety Inventory) and an improvement in symptoms (as measured by the Rotterdam Symptom Checklist [RSCL]; the subscales with improved scores were psychological, quality of life, severe physical, and severe psychological). The authors reported that the massage-only group showed improvement on four RSCL subscales; however, these improvements did not reach statistical significance.
In a placebo-controlled, double-blind, randomized trial of bergamot inhalation aromatherapy compared with a pleasant smelling shampoo that did not contain essential oils, administered at the time of stem cell infusion in 37 children and adolescents undergoing stem cell transplant, aromatherapy was not found to be beneficial in reducing nausea, anxiety, or pain. As administered in this study, bergamot inhalation aromatherapy may have contributed to persistent anxiety following the infusion of stem cells. Although no more effective than placebo, parents receiving aromatherapy showed a significant decrease in their transitory anxiety during the period between the completion of their child's infusion and 1 hour following infusion. Nausea and pain subsided over the course of the intervention for all children, though nausea remained significantly greater in patients receiving aromatherapy. These findings suggest that the diffusion of bergamot essential oil may not provide suitable anxiolytic and antiemetic effects among children and adolescents undergoing stem cell transplantation. The double blinding of the trial may explain the results, as single-blinded or nonblinded trials in general supported the aromatherapy intervention.