No effects of rosemary and lavender essential oil and a placebo pill on sustained attention, alertness, and heart rate

Abstract

Essential oils (EOs) are widely used for various purposes, however, their claimed effects are often not supported by empirical data. Previous findings have highlighted the importance of psychological factors (e.g. expectations) in their mechanism of action. The present study investigated the effects of an ingested placebo pill and inhaled rosemary and lavender oils on alertness and heart rate, as well as actual and perceived performance in a sustained attention task. 128 young adults, randomly allocated to four groups (rosemary, lavender, placebo pill with stimulant suggestion, and control), completed a vigilance task before and after the respective intervention. Compared to the control condition, no effects of the three interventions were found on actual changes in sustained attention, alertness, or heart rate. Both EOs and the placebo pill evoked positive expectations regarding cognitive performance and alertness. Expectations predicted perceived changes in alertness and heart rate, but not in cognitive performance. No differences between the two EOs and the placebo intervention were found in any respect. Psychological mechanisms behind the effects of inhaled EOs and placebos might be overlapping.

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

“…On the other hand, both odorants increased mood state after inhalation, but neither performance nor physiological arousal were affected. Similar findings have also been reported in a recent investigation by Babulka and co‐workers on the effects of rosemary and lavender essential oils on sustained attention and heart rate. Moss et al .…”

“…Ruling out olfactory perception of these fragrances, we expected to find activating effects after dermal administration of 1,8‐cineole and relaxing effects after dermal administration of (–)‐linalool. After inhalation, however, we hypothesized that the effects of both fragrances would be unspecific, since it has been argued that such effects are mainly psychological, i.e., dependent on the subjective perception of olfactory features and on expectations toward odors rather than physico‐chemical properties of odorants …”

Aromaterapia de Rosmarinus officinalis L. (Lamiaceae) em testes in vivo: revisão sistemática

“…As plantas medicinais apresentam diversos benefícios, como efeito nas funções cognitivas (memória, atenção, raciocínio e alerta), exemplos de espécies vegetais já testadas em relação a este efeito incluem o óleo de Mentha x piperita, C. odorata, R. officinalis, C. limon e L. angustifolia (Babulka et al, 2017;Yildirim & Kitiş, 2020). Yildirim e Kitiş 2020testaram em idosos a inalação de óleos de R. officinalis com C. limon durante cinco minutos, no período da manhã ao longo de 7 dias e verificaram que está mistura de óleos não apresentou eficácia sobre a sonolência dos idosos durante o dia, mais teve efeito sobre a melhora das funções cognitivas.…”

Super Pill is Less Effective than an Ordinary Mint in Altering Subjective Psychological Feeling States within a Few Minutes

“…The consumption of a Tic Tac is a pleasant event, which can be associated with the characteristic taste. Moreover, tastes and smells can directly impact one's mood through the limbic system (Babulka, Berkes, Szemerszky, & Köteles, 2017;Dobetsberger & Buchbauer, 2011;Jellinek, 1997). Briefly, the pleasant sensory experience and expected positive mood state associated with the mint might have played a stronger role in altering affect and wellbeing than expectancies evoked by the information participants received.…”

“…assessed using no self-report scales or assessed before and after the intervention) and subjective or perceived (i.e. assessed only after the intervention using self-report scales) effects (Babulka, Berkes, Szemerszky, & Köteles, 2017;Köteles & Babulka, 2014;Schwarz & Büchel, 2015). Expectancies usually have a greater impact on perceived effects than on the objective effects; in fact, they did not predict objective changes in many earlier studies (Babulka et al, 2017;Köteles & Babulka, 2014;Schwarz & Büchel, 2015;Szabo, Szemerszky, Dömötör, De la Vega, & Köteles, 2017;Szabo, Szemerszky, Dömötör, Gresits, & Köteles, 2017).…”