With Comments from Russell H. Greenfield, MD. Dr. Greenfield is Clinical Assistant Professor, School of Medicine, University of North Carolina, Chapel Hill, NC; and Visiting Assistant Professor, University of Arizona, College of Medicine, Tucson, AZ.
The Nose Knows: Lavender Aromatherapy and CVD
Source: Shiina Y, et al. Relaxation effects of lavender aromatherapy improve coronary flow velocity reserve in healthy men evaluated by transthoracic Doppler echocardiography. Int J Cardiol 2008;129:193-197.
Goal: To examine the effect of lavender aromatherapy on coronary blood flow and serum cortisol levels.
Study design: Single-blind intervention trial.
Subjects: Healthy young men (n = 30; mean age, 34 years).
Methods: In the evening after work, and in a generally relaxed environment, subjects had their coronary flow velocities in the left anterior descending artery recorded by non-invasive transthoracic Doppler echocardiography, and coronary flow velocity reserve (CFVR) was calculated. CFVR was assessed at baseline and immediately following 30 minutes of lavender aromatherapy, as were serum cortisol levels. As a control on a subsequent day, the trial was again performed on the same subjects, and their CFVR and cortisol levels determined, but without aromatherapy.
Results: Blood pressure and heart rate responses were not affected by lav-ender aromatherapy; however, CFVR increased and serum cortisol levels decreased after aromatherapy, but not in controls.
Conclusion: Lavender aromatherapy creates acute physiologic changes compatible with a relaxed state, including potentially beneficial effects on coronary blood flow in healthy young men.
Study strengths: Use of transthoracic Doppler echocardiography.
Study weaknesses: Limited generalizability (focus on healthy male subjects); an index of coronary microcirculation was calculated rather than actual determination of coronary flow volumes; subjects only had to refrain from smoking, antioxidants, caffeine, etc., for three hours before assessments took place; no determination could be made of potential long-term effects of aromatherapy or of repeated exposures; order of exposure probably should have been reversed (having previously experienced lavender aromatherapy, bias and altered physiology may have been introduced during the later control phase of the trial).
Of note: Females were excluded because CFVR is affected by the menstrual cycle; in this trial, aromatherapy was prepared by adding four drops of essential oil of lavender to 20 cc of hot water; CFVR is partially endothelium-dependent and is reportedly a physiologic index for coronary microcirculation; CFVR was calculated as hypermic diastolic flow velocity/basal mean diastolic flow velocity; prior studies have suggested that lavender aromatherapy provides both antioxidant and anticholinergic effects; 10 of the participants in this trial were smokers.
We knew that: Lavender aromatherapy has long been used as a means of inducing relaxation; mental stress has been reported to negatively impact coronary blood flow and to cause endothelial dysfunction, and is considered an independent risk factor for acute cardiac events; lavender aromatherapy has shown promise as an adjunctive treatment for central nervous system disorders such as Alzheimer's disease and Parkinsonism; stress-induced cardiac ischemia can occur at lower levels of oxygen demand than exercise-induced ischemia, and its occurrence does not correlate with angiographic evidence of coronary artery disease.
Comments: This interesting study is fraught with methodological concerns, but there is less a chasm needing to be bridged than a trough between the commonsensical and the scientific.
It is clear that psychosocial stress can have a negative impact on physiologic functions far from the brain, including impairment of cardiac function. Lavender aromatherapy, as anyone who has whiffed the scent can speak to, can be very relaxing and relaxation therapies appear to be effective at lessening the effects of noxious mental stress on cardiovascular parameters. It is not surprising, then, that this study's results suggest amelioration of stress-induced cardiac dysfunction with lavender, even in view of the trial's major shortcomings.
Perhaps the most important thing to be taken from this study is the additional fodder for discussion with patients of the importance of stress management. Many of the people practitioners meet with are disinclined to focus on their emotional or mental health; however, pointing out that psychosocial stress can impair heart function, and that relaxation techniques can at least partially reverse that impairment, often makes people more comfortable with the idea of stress management. This seems to be the case especially for men, who are often more likely to respond proactively to a physical health challenge than to what could be considered a strictly emotional one.
This trial does not stand up well on its own, but taken together with prior data, and a dollop of common sense, the data could be used to help support the argument that stress management as part of a long-term health plan can no longer be considered optional.
What to do with this article: Remember that you read the abstract.