Background

Green odor, a mixture of equal amounts of 2E-hexenal (leaf aldehyde) and 3Z-hexenol (leaf alcohol) has been demonstrated to have an anti-stress effect in rats. This study investigated whether or not green odor also has an anti-stress effect in humans.

Methods

Changes in blood pressure, heart rate, and the skin temperature of a fingertip were observed after presenting green odor at a concentration of 0.03% or vehicle via inhalation through the nose for 10 min to eight healthy normotensive adults. We also assessed the pleasantness of green odor and its effect on mood states via assessment with the Profile of Mood States (POMS) questionnaire. Cardiovascular response to green odor and the vehicle were compared among 11 additional healthy adults by use of the cold pressor test.

Results

Of 19 subjects, 15 (79%) reported that the green odor was pleasant. Green odor had no effect on blood pressure, heart rate, skin temperature, or POMS score under non-stressful conditions. In the second experiment, green odor attenuated cold pressor test-induced increases in systolic and diastolic blood pressure and facilitated the recovery of skin temperature.

Conclusion

These findings suggest that green odor has an anti-stress effect in healthy humans.