# The Combined Effects of Cold Foot Bath and Lavender Oil Inhalation on Autonomic Variables in Healthy Volunteers: A Randomized Controlled Trial

## TL;DR

This study finds that combining a cold foot bath with lavender oil inhalation can help relax healthy people by affecting their autonomic nervous system.

## Contribution

The novel contribution is the investigation of the combined effect of cold foot baths and lavender oil inhalation on autonomic variables in healthy individuals.

## Key findings

- The combination treatment significantly affected time-domain HRV variables like SDNN and pNN50.
- Frequency-domain analysis showed significant differences in LF and HF between the groups.
- The experimental group had significantly lower diastolic and systolic blood pressure than the control group.

## Abstract

Background and aim: An essential function of the autonomic nerve system is to regulate physiological processes and stress responses in the body. Cold foot baths and aromatherapy with lavender oil each influence autonomic functions, but their combined effect in healthy individuals is unknown. The purpose of this study is to look into how autonomic variability in healthy volunteers is affected by both inhaling lavender oil and taking cold foot baths.

Methods: A total of 60 healthy individuals were randomized to be placed in either the control group (n=30) or the experimental group (n=30) and were instructed to attend a single designated session. The control group underwent a 20-minute cold foot bath, while the experimental group received a 20-minute cold foot bath combined with lavender oil inhalation. Assessments were carried out before, during, and after the interventions.

Outcome measures: To evaluate autonomic variables, we monitored galvanic skin response (GSR) and Heart Rate Variability (HRV) using an equivital belt. Furthermore, we measured blood pressure (BP) and mean arterial pressure (MAP) before, during (20 minutes) the intervention, and after a 10-minute resting period; post-intervention measurements were taken.

Results: Repeated measures analysis revealed a significant difference in standard deviation of normal-to-normal intervals (SDNN), pNN50, and heart rate (HR) for time-domain variables (p<0.05), whereas the frequency-domain analysis showed a significant difference over time in LF/HF, LF, and HF (p<0.05). When these were compared between the groups, a significant difference was observed only in LF and HF (p<0.04). Additionally, a statistically significant difference (p<0.001) in diastolic and systolic blood pressure between the groups was noted.

Conclusion: The combination of a cold foot bath and lavender oil inhalation may modulate autonomic activity, promoting relaxation by vagal balance in healthy individuals.