Aroma Effects on Physiologic and Cognitive Function Following Acute Stress: A Mechanism Investigation

Abstract

Objective: Aromas may improve physiologic and cognitive function after stress, but associated mechanisms remain unknown. This study evaluated the effects of lavender aroma, which is commonly used for stress reduction, on physiologic and cognitive functions. The contribution of pharmacologic, hedonic, and expectancyrelated mechanisms of the aromatherapy effects was evaluated. Methods: Ninety-two healthy adults (mean age, 58.0 years; 79.3% women) were randomly assigned to three aroma groups (lavender, perceptible placebo [coconut], and nonperceptible placebo [water] and to two prime subgroups (primed, with a suggestion of inhaling a powerful stress-reducing aroma, or no prime). Participants' performance on a battery of cognitive tests, physiologic responses, and subjective stress were evaluated at baseline and after exposure to a stress battery during which aromatherapy was present. Participants also rated the intensity and pleasantness of their assigned aroma. Results: Pharmacologic effects of lavender but not placebo aromas significantly benefited post-stress performance on the working memory task (F (2, 86) = 5.41; p = 0.006). Increased expectancy due to positive prime, regardless of aroma type, facilitated post-stress performance on the processing speed task (F (1, 87) = 8.31; p = 0.005). Aroma hedonics (pleasantness and intensity) played a role in the beneficial lavender effect on working memory and physiologic function. Conclusions: The observable aroma effects were produced by a combination of mechanisms involving aromaspecific pharmacologic properties, aroma hedonic properties, and participant expectations. In the future, each of these mechanisms could be manipulated to produce optimal functioning.

Essential Oil of Japanese Cedar (Cryptomeria japonica) Wood Increases Salivary Dehydroepiandrosterone Sulfate Levels after Monotonous Work

“…None of the participants presented with any abnormality in terms of their physical, mental, or olfactory health or were currently using prescription drugs or were current smokers. While the purpose and schedule of the experiments were explained to the participants, the effects of the wood used in our experiments were not discussed to avoid the influence of individual expectations on the results [ 23 , 24 ]. Written informed consent was obtained from all participants prior to study initiation.…”

Aromatherapy Versus Pharmaceutical Interventions for Dementia Related Behaviors Translating & Integrating Scholarship Practicum

“…The respirations remained consistent with the placebo (water) group. Working memory testing revealed a 15% increase in scores for working memory with the lavender over the other groups [13]. The study concluded there was a positive correlation between lavender and working memory and a decrease in stress related physiological findings with both aromas in comparison to the placebo group.…”

“…Ninety-two individuals were randomly selected and placed into three aromatherapy groups which included lavender, a coconut, and a placebo (water) group. Cognitive and physical assessments were performed both before (for baseline) and after exposure to a stress battery [13]. Inclusion criteria included ages 50-85, no current medications and nonsmokers.…”

Effects of 1,8‐Cineole and (–)‐Linalool on Functional Brain Activation in a Working Memory Task

“…Volatile molecules are ubiquitous in our environment and have shown to be the active principle of many medicinal plants commonly used in phytotherapy. In addition, they may improve well‐being and work efficiency . Nevertheless, knowledge about their influence on the human organism is still very limited.…”