Researching essential oils

May 1, 2007
As your guest columnist this issue, I’ll explore the world of essential oils from the perspective of a neophyte.

by Cathy Hester Seckman, RDH

As your guest columnist this issue, I’ll explore the world of essential oils from the perspective of a neophyte. All I knew about essential oils, until recently, is that there are racks of them in health food stores. You’ve probably seen them too - dozens of tiny, brown, sometimes outrageously expensive bottles that contain concentrated herbal oils such as lavender and chamomile. I’ve always assumed people use them for potpourri, and that’s true. But there’s a lot more to know about essential oils.

A recent discussion on the List ( got me interested in researching the use of essential oils for sedation. It has been studied extensively in mice and rats, but there haven’t been many human trials. The reason for this is suggested in an essay published in the British Journal of General Practice in June 2000 called, “Why aromatherapy works (even if it doesn’t) and why we need less research.”

The author, Andrew Vickers of the Memorial Sloan-Kettering Cancer Center, points out that many human trials on essential oils test them as a lubricant used during massage. Since massage is part of most aromatherapy sessions (he cites his own work for this statement), and since massage has already been proven to be relaxing, aromatherapy must be relaxing, too. Therefore, he implies, a study of aromatherapy and essential oils is pointless and “not of pressing scientific importance.”

In the same issue of the British Journal of General Practice, two researchers published a review of 12 randomized controlled trials and concluded that while aromatherapy with massage may have a temporary effect in decreasing anxiety, there is no evidence of a lasting benefit.

The Center for Holistic Pediatric Education and Research conducted an open study that measured the effects of essential oils on cardiac patients. Twelve cardiac patients were given chamomile tea during catheterization procedures, and 10 of the 12 fell into a deep sleep 10 minutes after finishing the tea.

The United States Naval Medical Center in Portsmouth, N.H., is conducting clinical trials this year to test the possible reduction of conscious sedation required for colonoscopy patients by adding aromatherapy.

The randomized prospective blinded trial will add “pleasing olfactory stimulation” to inhaled oxygen during colonoscopy. The hope is that use of the essential oil (cherry, in this case) will reduce the amount of sedative required, thus making recovery easier and decreasing potential complications related to conscious sedation medication.

Pleasing smells can’t hurt

So, what does any of this have to do with us? Well, some researchers found evidence of transient anxiolytic and sedative effects with essential oils. It’s not much of a stretch to imagine placing a few drops of pleasant-smelling oil on a two-by-two on a patient’s chest for a possible hour’s worth of relaxation during dental treatment.

Could this work? Science hasn’t given us a definitive answer to that. Science has said, though, that as long as we’re careful about possible allergic effects, essential oils probably can’t hurt, and they might help.

Essential oils are difficult to produce, according to Jane Sheppard, a writer for the Healthy Child Web site. Sheppard said it can take 500 to 2,000 pounds of raw plant material to produce one pound of pure essential oil. The quality of harvesting, extracting, and bottling procedures, and whether the plants are grown organically, all affect the quality of the oil. An inexpensive oil, she said, will probably not give the results expected.

One interesting side note, according to Plant Physiology journal, is the fact that fragrance has been bred out of many modern flower varieties because there is a negative correlation between longevity and fragrance. The more fragrant a cut flower is, in other words, the more likely it is to deteriorate quickly. One example given was the common carnation, which originally had a spicy/clove odor because of its high eugenol content. In modern carnation varieties, there are low levels of eugenol and therefore little aroma.

Metabolic engineering to retrieve those long-lost fragrances is now possible, but not yet widespread. As aromatherapy gains popularity, fragrance engineering may become more important, and will likely center on ornamental plants rather than cut flower varieties.

The essential oils most commonly associated with relaxation, sedation, and decreased anxiety are Roman chamomile, lavender, rose, tea tree, mandarin, and peppermint. Chamomile is the leading choice. According to MedlinePlus from the National Library of Medicine, chamomile has been used for thousands of years and is still a popular treatment in Europe, especially in Germany. In Europe chamomile is used to treat everything from mouth ulcers to burns to the common cold. Its most widespread uses, though, are as an antispasmodic and a sedative.

This herb has a reputation for gentleness, but there are still reports of allergic reactions that include shortness of breath, throat swelling, and anaphylaxis. Anyone with allergies to ragweed or other plants in the Compositae family should avoid chamomile. Anyone taking other sedatives or anticoagulants should also avoid it. Pregnant and lactating women should not use chamomile. The most common side effect of chamomile, interestingly, is drowsiness. Chamomile can be used as a capsule or tablet, liquid extract, tincture, or tea.

There are dozens of Internet articles on the application of essential oils, but no way of judging which is best and safest. Herbal medicines are minimally regulated by the U.S. Food and Drug Administration, and no standardization among manufacturers exists.

There are no recommended dosages, but the usual dose of essential oils for adults is 1 to 4 ml three times daily. For young children, one to two drops of Roman chamomile or sweet orange on a cloth or gauze on their chest may be appropriate for relaxation and sedation, depending on age. However, anyone who exposes children or adults to essential oils must be educated on allergy and safety issues.

Should we try essential oils in our dental offices?

I might suggest it for adults, with approval from the practice owner. A thorough review of patients’ health status would be necessary, and patient education on essential oils is also indicated. The National Library of Medicine,, is a good source of information on herbs and essential oils.

Some patients might welcome the idea, and might already use herbs or oils for relaxation. Used cautiously, essential oils could be a welcome addition to our toolbox of patient management techniques.

Cathy Hester Seckman, RDH, is a frequent contributor based in Calcutta, Ohio. Besides working in a pediatric dental practice, Seckman is a prolific freelance writer, a book indexer, and a speaker on dental and writing/indexing topics. She can be reached at [email protected].


* “Why aromatherapy works (even if it doesn’t) and why we need less research,” Andrew Vickers

* “Aromatherapy: a systematic review,” Brian Cooke, Edzard Ernst

British Journal of General Practice, June 2000

* The Center for Holistic Pediatric Education and Research

* identifier: NCT00417001


* “Floral Fragrance. New Inroads into an Old Commodity”

Plant Physiology, December 2001, Vo. 127, pp 1383-1389