Short-term exposure to essential oils lowers blood pressure and heart rate

The scents which permeate our health spas from aromatic essential oils may provide more benefits than just a sense of rest and well-being.

For according to a new study in the European Journal of Preventive Cardiology, the essential which form the basis of aromatherapy for stress relief are also reported to have a beneficial effect on heart rate and blood pressure following short-term exposure - and may therefore reduce the . However, on the downside, those were reversed when exposure to essential oils lasted more than an hour.

The study was performed in men and women working in various spa centres in the city of Taipei in Taiwan, where the traditions of ancient Chinese civilisations are maintained in religious ceremonies and healing therapies. Aromatherapy, as practised today, is still presented as with essential oils extracted by infusion from aromatic plants.

One hundred young, healthy non-smoking spa workers taking part in the study visited the study centre on three occasions (about once a week), when each volunteer was exposed to vapours of essential oils released from an ultrasonic ioniser for two hours. During this time and on each visit three repeated measurements – , systolic blood pressure (SBP), and diastolic blood pressure (DBP) – were taken from each spa worker in the study room, a small space measuring 4 metres in height by 3.5 m in length and 3.2 m in width. Before each participant entered the study room, 100% pure bergamot essential oil was vaporised for 1 hour.

Essential oils are (VOCs) composed of hundreds of aromatic chemicals, and VOC levels in the room were also measured throughout the study period.

Results showed (after adjusting for age, sex, BMI, day of the week, and visit order) that the room's VOC level was significantly associated with reduced blood pressure and heart rate for between 15 and 60 minutes after the start of exposure. These associations were statistically significant. For example, after 45 minutes exposure 15-minute SBP had reduced by a mean of 2.10 mmHg and heart rate by 2.21 beats per minute.

However, after exposure for more than 1 hour - from 75 to 120 minutes after the start of exposure - VOC levels became associated with an increased 15-minute mean blood pressure and heart rate. After 120 minutes, for example, mean SBP had risen from baseline by 2.19 mmHg, and heart rate by 1.70 beats per minutes. Thus, say the authors, "prolonged exposure for longer than 1 hour to essential oils may be harmful to in young, healthy subjects".

As background to the study the authors note that aromatherapy has long been used for and associated with some healing properties. Even exposure to the essential oil vapours from fragrant candles has been found to reduce test-taking anxiety among nursing school students in the USA.

However, says investigator Dr Kai-Jen Chuang from Taipei Medical University in Taiwan, it is still unknown if exposure to essential oil increases the risk of cardiovascular events through a partial effect on blood pressure and heart rate.

"Our results suggest that exposure to essential oil for 1 hour would be effective in reducing heart rate and blood pressure," said Dr Chuang. "However, the most interesting finding of our study is that exposure to essential oil for over an hour was associated with elevated and ."

Dr Chuang explained that, although the effect of essential oils on stress reduction has been well documented, epidemiological studies have reported an association between VOCs and cardiopulmonary effects - asthma among hairdressers, for example. Studies by Chuang's own group in Taiwan have already shown that exposure to VOCs for over an hour in hair salons can lead to increased serum levels of C-reactive protein (a marker of inflammation) and 8-OHdG (a marker of oxidative stress). Overexposure to , he suggested, may in such ways be harmful to cardiovascular health in young, healthy subjects.

He also noted the opinion of the American Heart Association on air pollution in the development of cardiovascular disease. This acknowledges the direct effects of air pollution on the lung and cardiovascular system through neural and central mechanisms to cause a systemic inflammatory response. "These potential biological processes may also be applied to the adverse effects of VOC exposure on cardiovascular health, although at this time there is no proof available for this hypothesis," said Dr Chuang.

More information: Chuang K-J, Chen H-W, Liu I-J, et al. The effect of essential oil on heart rate and blood pressure among solus por aqua workers. Eur J Prevent Cardiol 2012; DOI: 10.1177/2047487312469474

Related Stories

Can aromatherapy produce harmful indoor air pollutants?

Oct 20, 2011

Spas that offer massage therapy using fragrant essential oils, called aromatherapy, may have elevated levels of potentially harmful indoor air pollutants such as volatile organic compounds (VOCs) and ultrafine ...

Living with a smoker may raise blood pressure in boys

May 01, 2011

Exposure to secondhand smoke, even at extremely low levels, is associated with increased blood pressure in boys, according to new research being presented Sunday, May 1, at the Pediatric Academic Societies (PAS) annual meeting ...

Aromatherapy: more than just a pleasant scent?

Apr 26, 2012

(HealthDay) -- Aromatherapy is beginning to enter the medical mainstream, with groups as diverse as the American Cancer Society and the U.S. Department of Veterans Affairs touting the use of fragrance as a ...

Recommended for you

Gene variant raises risk for aortic tear and rupture

Apr 17, 2014

Researchers from Yale School of Medicine and Celera Diagnostics have confirmed the significance of a genetic variant that substantially increases the risk of a frequently fatal thoracic aortic dissection or full rupture. ...

Considerable variation in CT use in ischemic stroke

Apr 17, 2014

(HealthDay)—For patients with ischemic stroke there is considerable variation in the rates of high-intensity computed tomography (CT) use, according to a study published online April 8 in Circulation: Ca ...

Beating the clock for ischemic stroke sufferers

Apr 17, 2014

A ground-breaking computer technology raises hope for people struck by ischemic stroke, which is a very common kind of stroke accounting for over 80 per cent of overall stroke cases. Developed by research experts at The Hong ...

User comments