Effects of high-concentration aromatic environments on sleep quality: Taking bergamot as an example

Aromatic compounds have the potential to improve sleep quality. However, little research specifically targeted healthy groups, particularly concerning the concentration of aromatic substances in the environment and their effects on sleep quality. To address this gap, this study utilized bergamot essential oil to investigate the impact of high-level aromatic settings. Conditions of 9 μg/L and 12 μg/L were established for a chamber experiment involving 16 healthy subjects. The results showed that in the environment with an aromatic concentration of 9 μg/L, sleep onset latency (SOL) and slow wave sleep (SWS) did not show a significant difference compared to the non-aromatic environment. However, when it was increased to 12 μg/L, subjects’ SWS values were significantly lower than those in the non-aromatic environment (P = 0.03). Subjective questionnaire results also indicated a significant decrease in the calmness of sleep (P = 0.024). Additionally, this study found that under a high-concentration aromatic setting, the SOL of females significantly reduced (P = 0.046), while males exhibited a shorter duration of SWS compared to females (P = 0.046). Therefore, when creating an aromatic sleeping environment, it is advisable to avoid excessively high concentrations of aromatic substances and to take into account the physiological characteristics and olfactory preferences of different sexes.