by Dr. Barrie Cassileth PhD Laurance S. Rockefeller Chair and Chief of the Integrative Medicine department at Memorial Sloan-Kettering Cancer Center
An ongoing series highlighting complementary therapies, adapted from The Complete Guide to Complementary Therapies in Cancer Care
A combination of folk wisdom and accident merged to become the modern practice of aromatherapy, which involves the use of oils distilled from plants for therapeutic purposes. It has a long history of use in ancient Egypt, China, and India. The distillation method used to extract essential oils was invented by an Arab physician in the tenth century A.D.
Modern aromatherapy in the West began with a French chemist, René-Maurice Gattefossé. Working one day in the laboratory at his family’s perfume company, he burned his hand. He quickly doused his hand with some readily available lavender oil. The burn healed quickly and left no scar, piquing his interest in the possible curative effects of plant oils. He began to study them, coining the term aromatherapy in the 1930s to describe this new field.
What It Is
Aromatherapy is the use of essential oils, which are natural, high-quality, pure oils derived from the distillation of plants. The oils are named for the plant from which they are derived, such as lavender, rose, and eucalyptus. They are highly concentrated: between 50 and several thousand pounds of plant material are required to make 1 pound of essential oil, depending on the plant. At least 40 essential oils are used in aromatherapy. Each is categorized according to its effects on the body, the mind, and the diseases it is said to treat. Oils from various plants may be used individually or in combinations.
Aromatherapy is delivered to patients in several ways. Oils can be applied directly to the skin through massage or as a liniment. For skin application, the oils are combined with a carrier medium, usually a vegetable oil, because the amount of essential oil required is so small.
The oils also may be inhaled in steam from water containing a few drops of an essence or by using diffusers to spread oil-containing steam throughout a room. Because they are highly concentrated, essential oils are potentially toxic and should not be taken internally.
Aromatherapy can be self-administered or received from a practitioner. Several organizations in Europe and North America train and certify aromatherapists. Aromatherapists sometimes combine knowledge of aromatherapy with other practices, such as traditional Chinese healing or herbal medicine.
What Practitioners Say It Does
Aromatherapy has three main functions. The first is stress reduction, which is achieved primarily through the personal use of aromatic oils in one’s workplace or home, or by combining aromatherapy with other stress reduction activities, such as soaking in a hot bath treated with scented oil or receiving a massage accompanied by aromatherapy.
The second function is preventive. According to some advocates, aromatherapy can balance and increase the well-being of both body and mind, thus decreasing the likelihood that disease will develop. The third function is therapeutic. Aromatherapy is used to treat physical and mental ailments. Lavender, for example, is used to treat anxiety, mild depression, and insomnia.
Conditions that practitioners believe to be aided by aromatherapy include acne, anxiety, cold and flu, headaches, indigestion, muscle tension, premenstrual syndrome, skin disorders, and pain. Some aromatherapy advocates use body applications (massages and liniments) to treat physical problems and inhalation methods to treat emotional problems.
Beliefs on Which It Is Based
Aromatherapy rests on two central principles, one well known to science and the other as yet unproven. The first is that aromatherapy is based on the sense of smell, which is extremely acute in humans and other animals. Very small amounts of a scent trigger the sense of smell by activating receptors in the nasal cavity. These receptors are neurons, or nerve cells, which translate the odor into nerve impulses, enabling them to travel instantly to the olfactory bulb, which is part of the limbic system, the area of the brain that scientists have identified with memory and emotion. The sense of smell has been studied extensively for its role in communication and memory.
The second but unproven belief on which aromatherapy is based is that essential oils, through the sense of smell or by absorption through the skin, can affect the body’s health.
Research Evidence to Date
Substantial research evidence exists about the olfactory system (the sense of smell). For example, a single waft of an odor can trigger memories from decades back. This was captured in Marcel Proust’s famous passage in his novel Remembrance of Things Past, when the author was flooded with childhood memories as he bit into a madeleine, a French tea cake made for him as a child.
In addition, scientists have found substances called pheromones in almost all creatures. These chemicals are emitted by the body and sensed by the olfactory system. In mammals, pheromones play a role in sexual attraction and mating. In other organisms they facilitate not only mating but also the attraction of prey and forms of communication. Pheromones are responsible for a phenomenon called menstrual synchrony, where the menstrual cycles of women who live in close proximity, such as in a college dorm, often become similar or synchronized with one another.
Some studies implicate the sense of smell in illness and relaxation. One researcher found that certain odors could trigger migraines in some individuals and, alternatively, that the fragrance of green apples may heighten feelings of relaxation.
What It Can Do for You
Like other complementary methods, aromatherapy may reduce stress, enhance pleasure, and improve quality of life for those to whom it appeals. There is no evidence in the medical literature, however, that supports claims by proponents that aromatherapy can help prevent or heal disease. Evidence is lacking even in the case of minor and self-limiting conditions, such as headaches and colds, that advocates say can be alleviated or abbreviated by aromatherapy. The medical literature contains no research on the effects of aromatherapy as a medical treatment.
Used as a strictly complementary technique, however, aromatherapy is a pleasant addition to baths and massages. Scented candles and aroma sprays, for those who enjoy the fragrance, contribute to a sense of relaxation and help create a calming atmosphere.
A few caveats: The essential oils of aromatherapy never should be swallowed or taken into the body through other routes. Also, prolonged, extensive exposure to essential oils should be avoided, as reports in the medical literature indicate that such use has produced allergic reactions in some people.
Where to Get It
More than 6 million websites promote aromatherapy and sell related products. Books are also readily available as are organizations that will locate sources of essential oils and aromatherapists in your area.
Adapted with permission from The Complete Guide to Complementary Therapies in Cancer Care: Essential Information for Patients, Survivors and Health Professionals. Copyright © 2011 by World Scientific Publishing Co. Pte. Ltd.