Romane Schönholzer

Aromatherapy proposes to use aromatic material for improving psychological and physical well-being. To test the efficacy of this therapy, we quantified the effect of essential oils on the autonomic nervous system and our emotions. The study involved 85 participants who inhaled for 10 minutes either lavender, rosemary, or almond oil (placebo). Blood pressure, heart rate, oxygen saturation and emotional state were measured before and after the inhalation and compared to the placebo. The placebo showed little to no significant effect (no placebo effect). The effect of rosemary oil depends on the person. Despite that no significant changes of the autonomic nervous system were measured, the participants described themselves as happier after the inhalation. Participants who inhaled lavender oil described themselves as happier and more relaxed, which is corroborated by a significant decrease of the systolic blood pressure (−6,30 𝑚𝑚𝐻𝑔 ± 8,10). This decrease is similar to the one observed with a diuretic, a standard treatment for hypertension. This study demonstrates that inhaling essential oils has a significant effect on emotions and/or autonomic nervous system. In particular, it points that lavender oil, already known for its antioxidant, analgesic and anti-inflammatory effects, could be used as a natural alternative to treat hypertension.