Lavender Oil Bronchodilation Effect: A Pilot Study

Abstract

Background: Essential oils (EOs) are combinations of volatile organic compounds that have been used to induce various effects on the body via neurological and pharmacological pathways (Horvath and Acs 2015), including altering respiratory infections and inflammatory response in asthma. Lavender oil (LO) is thought to alleviate symptoms of bronchial asthma through attenuation of the inflammatory cell response and mucous cell hyperplasia. One study (Ueno-lio et al 2014) found the inhalation of lavender oil in mice to reduce the number of eosinophils and total white blood cell count in bronchoalveolar lavage fluid, reduced numbers of IL-4, 5, and 13 in lung tissue, and reduced Muc5b expression in lung tissue. However, studies have yet to replicate these results in mice models and the LO was inhaled over a period of days before data was collected (Ibid). Although human EO use is common, it is not known if LO can attenuate inflammatory and hyperreactive airway response in humans. We investigated if brief inhalation of LO produces a rapid improvement in breathing effort (eg, less airways resistance (RAW), improved FEV₁, FVC, FEV₁%) after a brief period of exercise.

Methods: This IRB-approved study of seven healthy adults (6 female, ages 21-33 y) measured lung function via spirometry and plethysmography following ATS guidelines (FVC, FEV₁ and RAW) at baseline, after a 6-min stair climb challenge and after inhalation of LO (source: DoTERRA, Pleasant Grove, UT) passively diffused from a gauze patch placed on the chin for 15 min. Two drops of undiluted stock solution (half the manufacturer's maximum recommended dose for diffusion) was used for each participant (one drop = 0.05 mL).

Results: Using Friedman's Test, the only significant change detected was a decrease in FEV₁ (P <.005, reference table) when all three measurements were compared (did not meet Am Thoracic Society standard for bronchodilator response).

Conclusions: A brief (15 min) inhalation of LO post stair challenge did not improve lung function as measured by FEV₁, FVC, FEV₁% or RAW. Subjects exhibited no negative effects from inhalation of undiluted LO. The FEV₁ did statistically decrease (but not clinically) from baseline to final measurement. A control comparison would be needed to determine if the decrease would have been greater without LO inhalation. A next step would be exposing known asthmatic subjects to a longer period of LO inhalation.