Alleviation of physiological stress response by apple aroma.

Objective: The study evaluated the potential of apple aroma to alleviate physiological stress response induced by a short-term cognitive stressor. It investigated the effects of apple aroma on cardiac and peripheral autonomic nervous system activity under stressful conditions.

Methods: Within-subject experiments were conducted with 25 healthy male university students with a 30-minute calculation task under three conditions: Apple, Chamomile (CHA), and Di propylene glycol (DPG) (scentless air). The aroma administration was precisely controlled and counterbalanced. Cardiac activity on electrocardiograms and nose tip temperature were recorded throughout the experiment. A visual analog scale and a scent questionnaire were subjective measures.

Results: Apple aroma demonstrated a significantly smaller increase in heart rate (t [24] = 3.36, p = 0.008 vs. DPG, t [24] = 4.06, p = 0.001 vs. CHA), and a decrease in the high-frequency component of heart rate variability (t [24] = 2.81, p = 0.029 vs. DPG, t [24] = 3.48, p = 0.006 vs. CHA) compared to the other conditions, representing a smaller enhancement of cardiac sympathetic nervous system activity and smaller suppression of cardiac parasympathetic nervous system activity respectively.

Conclusion: Apple aroma showed efficacy in alleviating the physiological stress response in terms of cardiac activity. Apple was also considered significantly preferable and comfortable compared to the other conditions, which would be beneficial in the context of aromatherapy.