Trial of Essential Oils to Improve Sleep for Patients in Cardiac Rehabilitation.
Level 2 - randomized trial
Randomized double-blind crossover trial in humans
PubMed 31556690 · doi:10.1089/acm.2019.0222
What was done
Researchers conducted a randomized, double-blind crossover trial involving 42 adult patients enrolled in an outpatient cardiac rehabilitation program in an urban hospital in North Texas. Participants placed cotton balls infused with either a blend of essential oils (lavender, bergamot, and ylang ylang) or a placebo at their bedsides for five nights. Following a washout period, subjects crossed over to the alternate condition for another five nights. Sleep quality was evaluated after each period using the Pittsburgh Sleep Quality Index (PSQI).
What was found
Global PSQI scores were significantly lower (indicating better sleep quality) during the essential oil phase compared to the placebo phase (mean = 4.9 vs. mean = 8.0). Total sleep duration and sleep latency did not differ between conditions. However, subjective sleep quality was significantly improved with essential oils (chi-squared = 4.5, p = 0.03). Participants also reported waking up less frequently to use the bathroom (t = -2.04, p = 0.05) and having less sleep disturbance from feeling cold (t = -2.03, p = 0.05) during the essential oil intervention.
Why it matters
This study suggests that bedtime aromatherapy may serve as a simple, low-cost, non-pharmacological option to improve subjective sleep quality in patients recovering from cardiac hospitalizations.
Limits
The sample size was small (n = 42) and drawn from a single outpatient center. Outcomes relied entirely on subjective self-reporting through the PSQI rather than objective sleep metrics such as polysomnography or actigraphy. The duration of each intervention arm was very brief (five nights), and blinding integrity can be challenging with aromatic interventions.
Cited by
- supports Lavender, ylang-ylang, and vanilla aromatherapy have scientific evidence showing they improve sleep.