Physiological and behavioral effects of 1,8-cineol and (±)-linalool: A comparison of inhalation and massage aromatherapy

Abstract

The effects of fragrances on human arousal are not well understood. The aim of the present investigation was to determine the influence of two monoterpenes, 1,8-cineol and (±)-linalool, on human sustained attention, physiological arousal and well-being. The substances, as well as appropriate placebos, were administered either by inhalation or by skin application to a total of 130 healthy subjects. We found that when the fragrances were applied to the skin 1,8-cineol improved speed of attentional performance in comparison to (±)-linalool, but not in comparison to peanut oil, which served as a placebo. Under the same conditions, 1,8-cineol increased respiration rate in comparison to both (±)-linalool and placebo. In the inhalation condition, neither attentional performance nor physiological arousal were affected by the fragrances, but both odorants influenced wellbeing, i.e., 1,8-cineol decreased activation and (±)-linalool increased it. In contrast, no such effects were observed in the skin application condition. Our results demonstrate that fragrances affect cognitive performance, physiological arousal and well-being as a function of the mode of administration.