The effects of orally administered lavender in response to mood eliciting film clips on male and female participants
Lavender odour is commonly used to alleviate mild anxiety; but there are few reliable investigations of its efficacy because double blind studies are difficult to conduct with odours. The effects of lavender capsules (placebo, 100µl, 200µl) orally administered were tested in a randomised between subjects (n=97) double blind laboratory study. Film clips were used to elicit anxiety. Psychological measures included Spielberger's state/trait anxiety inventory, and the positive/negative affect scales. Physiological measures included heart rate, HR, galvanic skin response, GSR, and heart rate variation, HRV. Procedure: baseline measures were taken whilst participants relaxed; next capsules were administered and they watched a neutral, an anxiety and then a light hearted recovery film clip. During the neutral film clip 100µl lavender decreased negative affect (p<0.05); whereas 200µl lavender decreased state anxiety (p<0.05) and sympathetic arousal, GSR (p<0.05), and HR (p<0.05). During the recovery film lavender facilitated recovery at both doses, sympathetic arousal decreased (GSR 100µl p<0.01, 200µl, p<0.05). Lavender also had differential effects according to gender. In males' 200µl lavender increased sympathetic arousal during the anxiety film (GSR, p<0.05); whereas in females HRV significantly increased during all three film clips at 200µl lavender (p<0.05). Increased HRV is an indication of relaxation. Orally administered lavender may have beneficial effects in improving mood and physiological relaxation in non-anxious participants. While in females lavender caused increased relaxation during all phases of the study. In males lavender decreased relaxation during the anxiety film by increasing sympathetic arousal.
Acknowledgements: The authors would like to thank Dr Paul Pollard (Head of School) and Professor John Archer (Head of Research) for their support of this work and UCLAN, Preston UK.