Published Scientific Literature

        While the uses and benefits of specific essential oils could easily be identified in advertisements and non-scientific literature; it is almost impossible to find
studies on the uses of all (or even the four covered earlier in this paper) essential oils.
Therefore, only lavender and chamomile will be addressed in this portion of the paper.
There is no scientific clinical data to support the claim that lemon and clary sage have any
use in stress reduction
         One study conducted by a cardiac intensive care nurse and trained aromatherapist
and stress management consultant at Exeter University revealed that aromatherapy, and
especially the use of the essential oil lavender, has measurable therapeutic effects on post
cardiotomy patients.
         In this study 28 patients were evaluated using a detailed questionnaire on levels of
anxiety, mood, and their ability to cope with their situation both pre- and post- treatment
on two consecutive days. Two different species of the lavender plant were diluted into
coldpressed almond oil and labeled lavender A and lavender B. Both researcher and
patient were kept blind as to which oil was being used. Specified areas of the body were
massaged using either lavender A or lavender B.
         Lavender A was found to be almost twice as effective as Lavender B in alleviating
anxiety, although mood and coping abilities remained the same. This proves that there are
therapeutic effects of lavender and results were not simply due to massage, touch, or placebo. The choice of essential oil is important.
         But, there remains a few problems with this study. First the study was small and
confined to a specific group of patients. The method for obtaining information of stress,
anxiety, and coping abilities was not sophisticated and was very generalized. Blood
samples to show adrenocorticosteroid levels could be added to strengthen the results of
the study (Buckle 1993).
         Another study conducted at the Royal Bershire Hospital in Reading, England
provided similar findings. In this randomized controlled clinical trial 122 patients admitted
to the general intensive care were randomly assigned to one of three groups. The subjects
either received massage, aromatherapy using the essential oil of lavender, or a period of
rest. It was found that the the group who received aromatherapy reported a significant
improvement in their mood, perceived level of anxiety, and were more positive
immediately following the therapy. But, there was no statistically significant differences in
the physiological stress indicator either observed or reported by the patients or researchers
(Dunn, et al. 1995).
          At the Middlesex Hospital in the Intensive Therapy Unit in 1991-1992 a
study was conducted to evaluate the effects of aromatherapy (essential oil use) foot
massage on patients one day after cardiac surgery. Patients were divided into four groups.
One control group which had no intervention, another control group received a 20
minute chat without tactile input; one test group received a 20 minute foot massage using
plain vegetable oil; and the experimental group received a neroli (orange blossom)
essential oil foot massage for 20 minutes.
         Each group was assessed by a independent recorder both physiologically and
psychologically before and after the 20 minute treatment, or 20 minute control
intervention. Heart rate, blood pressure, and respiratory rate were measured in addition to
a questionnaire used to measure a subjects psychological state looking at anxiety, pain,
calmness, restfulness, and relaxation.
         It was found that there were significant short term psychological results in the two
massage groups, much more improvement than the two control groups. No significance
different was seen between the plain oil group and the neroil group. But, those results
changed when long term differences were evaluated. On day five patients perception of the effects of the massage were very positive. The aromatherapy group found the effects more relaxing, calming and restful than the plain oil group. The aromatherapy group also found the positive effects to last longer than the other groups.
         In her review paper published in The Hospice Journal in 1998 Carol Howdyshell
evaluated the effectiveness of aromatherapy on the care of elderly and hospice patients.
She found that the use of certain essential oils enhances the quality of life of these patients
by relieving stress. She cites many studies. One study assessed the effectiveness of
reducing stress in patients enrolled in occupational therapy. The researchers administered
lavender oil by hand massage or as a fragrance for fifteen minutes prior to occupational
therapy. This appeared to cause a relaxation and opening out of the hands which in turn
resulted in a more effective and productive occupational therapy session (Sanderson and
Ruddle, 1992).
         Another study that Howdyshell reviewed in her article was one performed by
Wendy Maddocks in 1994. In her study Maddocks replaced a patients (an elderly person)
daily dose of Temazepam (a sleep aid) with a session of aromatherapy inhalation using
lavender and geranium. This was found to be effective in promoting relaxation and sleep
(Maddocks, 1994).
         Although much of the information available on aromatherapy and the use of
essential oils claim that each plant can alleviate many symptoms, very few clinical studies
have been conducted on the use of specific oils.
         Another controlled trial study found that adding Roman chamomile to a massage
reduced anxiety and improved the quality of life among 51 cancer patients to a greater
extent than unscented oil did (Wilkinson 1995).
         In England at the Hinchingbrook Hospital a study was performed in early 1994
that found that the use of lavender in bath water is effective in reducing discomfort in
women after childbirth. A clinical randomized trial on a total of 635 women was used with
no side effects were found (Dale, Conrwell 1994).
         At the Tullamore Nursing Development Unit at Genera Hospital, Co. Offaly, in
Eire, researchers have been addressing way to improve the quality of nursing practice
offered to patients. The NDU reported in a journal article of The Complementary Therapy
Nurse Midwifery in 1996 that the “use of aromatherapy has significantly improved the
sleep patterns of the patients.” This article, although, does not provide any information of
the collection techniques or research methods implemented in this study.
         Since there exists little data on the effects of essential oils on humans, studies
which were performed on animals can provide us with some useful insight. A study
conducted at The Tokyo University of Pharmacy and Life Science found that rats which
inhaled chamomile oil vapor had a decrease in stress-induced increases in their plasma
ACTH levels (Yamada, Miura, Sashida 1996).
         Also, at the Department of Clinical Veterinary Medicine, University of Cambridge
researchers studied pigs to see if the use of lavender straw is effective in reducing travel
sickness and stress. Forty 70-kg pigs were transported by road for 2 hours, 20 animals
each day for 2 days. On day one wheat straw was used as bedding. On day 2 lavender
straw was provided as bedding. Direct behavioral observations were made during the
journey. Researchers marked the pigs and scanned them every 10 minutes and recorded
both general activity index and signs of travel sickness. The final conclusion arrived at was
that lavender straw decreased the incidence and severity of travel sickness but did not
greatly affect the level of stress (as measured by concentration of salivary cortisol)
(Bradshaw et al, 1998).

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