Human behavioral and physiological reactions to inhalation of sweet orange oil

Abstract

Although essential oils are used increasingly for the improvement in quality of life as well as for the relief of various symptoms in patients, scientific evaluation of the effects of fragrances in healthy volunteers is rather scarce. Up to now, no experiments about the effects of sweet orange oil (Citrus sinensis) on human physiological parameters and on behavioral measures after inhalation have been carried out. Therefore, the main objective of the present study was to investigate the effects of this fragrance compound on physiological parameters as well as selfevaluation in healthy human subjects following inhalation. Physiological parameters recorded were blood pressure, breathing rate, skin temperature, and heart rate. Self-evaluation was assessed in terms of alertness, attentiveness, calmness, mood, relaxation, and vigour. Additionally, the fragrance was rated in terms of pleasantness, intensity, and effect. Sweet orange oil caused significant increases in heart rate as well as in subjective alertness, which are likely to represent a stimulating effect of the oil. These findings furnish scientific proof for the use of sweet orange oil in aromatherapy for the relief of mild forms of depression and stress in humans. © ISHS 2005.