Effects of Peppermint and Lavender Odors on the Human Body during a Footbath at Water Temperatures of 36°C and 40°C

This research examined the effect of two different odors (peppermint and lavender) on the human body whilst the subjects took a footbath at water temperatures of 36°C and 40°C. The subjects were 12 healthy college students (male). The experiment was divided into two periods. The first was the baseline period of 5 minutes during which the students merely remained seated. During the second period the students continued to remain seated but immersed their feet in a footbath for 11 minutes. At the same time the students were exposed to different odors. Peppermint was used for the odor termed ´refreshing´ and lavender was used for the odor termed ´relaxing´. The results of our experiments showed that the use of peppermint resulted in a significant increase in energy expenditure as compared with the absence of odors. Inversely, lavender resulted in a significant decrease on energy expenditure and O2Hb: cerebral blood flow. We think that the lavender odor affected the Parasympathetic nerve system, while peppermint had an inverse effect on the sympathetic nerve system. At 40°C the lavender odor also showed a notable effect on the subjects´ physiological and psychological performances.