Lavender aromatherapy improved sleep quality among middle-aged women with insomnia, according to recent research.
The study, “The Effect of Lavender Aromatherapy on Autonomic Nervous System in Midlife Women with Insomnia,” involved 67 women ages 45 to 55, recruited voluntarily from a health-care program on sleep hygiene. These subjects met the criteria for insomnia according to the Pittsburgh Sleep Quality Index.
Researchers randomly assigned the women to either the experimental group or the control group. Those in the control group participated in a health education program on the topic of sleep hygiene, with no additional intervention. Subjects in the experimental group received 20 minutes of lavender inhalation twice a week for 12 weeks.
For these aromatherapy sessions, the women were instructed to avoid caffeine and alcohol for at least three hours before the session was scheduled to start. After relaxing in a comfortable chair for 10 minutes, the lavender inhalation began. Researchers used 0.25 milliliters of lavender essential oil and 50 milliliters of water in an ultrasonic ionizer aromatherapy diffuser, kept 10 to 15 centimeters away from the subjects during each aromatherapy session.
Outcome measures included heart-rate variability (HRV) analysis and the Pittsburgh Sleep Quality Index. For both the control and experimental groups, HRV measurements took place before the start of the study, as well as one month and three months after the 12-week study period ended. In the experimental group, HRV measurements also occurred before and 10 minutes after aromatherapy in weeks four and 12 of the study period. In addition, all subjects in the study were screened using the Pittsburgh Sleep Quality Index at the start and end of the research period.
Results of the research revealed significant changes in heart rate among the women in the aromatherapy group following 20 minutes of lavender inhalation. These changes included a decrease in mean heart rate and increases in time domain analysis HRV parameters. According to the researchers, such changes reflect parasympathetic influences. However, these beneficial effects on HRV were no longer in effect one month and three months after the aromatherapy intervention ended.
Scores on the Pittsburgh Sleep Quality Index showed that the women in the aromatherapy group experienced statistically significant improvements in sleep quality after the lavender inhalation, compared to no such improvements among the control group.
“The study demonstrated that lavender inhalation may have a persistent short-term effect on HRV with an increase in parasympathetic modulation,” state the study’s authors. “Women receiving aromatherapy experienced a significant improvement in sleep quality after intervention. However, lavender aromatherapy does not appear to confer benefit on HRV in the long-term follow-up.”
Authors: Li-Wei Chien, Su Li Cheng and Chi Feng Liu.
Sources: Department of Obstetrics and Gynecology, College of Medicine, Taipei Medical University Hospital, Taiwan; National Taipei University of Nursing and Health Sciences, Taiwan; and Graduate Institute of Integration of Traditional Chinese Medicine with Western Nursing, National Taipei University of Nursing and Health Sciences, Taiwan. Originally published in Evidence-Based Complementary and Alternative Medicine (2012).