Aromatherapy is the use of essential oils from plants to support and balance the mind, body, and spirit. It is used by patients with cancer mainly as a form of supportive care that may improve quality of life and reduce stress and anxiety. Aromatherapy may be combined with other complementary treatments like massage therapy and acupuncture, as well as with standard treatments.
Essential oils (also known as volatile oils) are the basic materials of aromatherapy. They are made from fragrant essences found in many plants. These essences are made in special plant cells, often under the surface of leaves, bark, or peel, using energy from the sun and elements from the air, soil, and water. If the plant material is crushed, the essence and its unique fragrance are released.
When essences are extracted from plants in natural ways, they become essential oils. They may be distilled with steam and/or water, or mechanically pressed. Oils that are made with chemical processes are not considered true essential oils.
There are many essential oils used in aromatherapy, including Roman chamomile, geranium, lavender, tea tree, lemon, cedarwood, and bergamot. Each type of essential oil has a different chemical structure that affects how it smells, how it is absorbed, and how it is used by the body. Even varieties of plants within the same species may have chemical structures different from each other because they are grown or harvested in different ways or locations.
Essential oils are very concentrated. For example, it takes about 220 lbs of lavender flowers to make about 1 pound of essential oil. Essential oils are very volatile, evaporating quickly when they come in contact with air.
Fragrant plants have been used in healing practices for thousands of years across many cultures, including ancient China, India, and Egypt. Ways to extract essential oils from plants were first discovered during the Middle Ages.
The history of modern aromatherapy began in the early 20th century, when French chemist Rene Gattefosse coined the term "aromatherapy" and studied the effects of essential oils on many kinds of diseases. In the 1980s and 1990s, aromatherapy was rediscovered in Western countries as interest in complementary and alternative medicine (CAM) began to grow.
Aromatherapy is rarely suggested as a treatment for cancer, but rather as a form of supportive care to manage symptoms of cancer or side effects of cancer treatment. There are different theories about how aromatherapy and essential oils work. A leading theory is that smell receptors in the nose may respond to the smells of essential oils by sending chemical messages along nerve pathways to the brain's limbic system, which affects moods and emotions. Imaging studies in humans help show the effects of smells on the limbic system and its emotional pathways.
Aromatherapy is used in various ways. Examples include:
Aromatherapy is rarely taken by mouth.
There are some essential oils commonly chosen to treat specific conditions. However, the types of oils used and the ways they are combined may vary, depending on the experience and training of the aromatherapist. This lack of standard methods has led to conflicting research on the effects of aromatherapy.
Many studies of essential oils have found that they have antibacterial effects when applied to the skin. Some essential oils have antiviral activity against the herpes simplex virus. Others have antifungal activity against certain vaginal and oropharyngeal fungus infections. In addition, studies in rats have shown that different essential oils can be calming or energizing. When rats were exposed to certain fragrances under stressful conditions, their behavior and immune responses were improved.
One study showed that after essential oils were inhaled, markers of the fragrance compounds were found in the bloodstream, suggesting that aromatherapy affects the body directly like a drug, rather than indirectly through the central nervous system.
Clinical trials of aromatherapy have mainly studied its use in the treatment of stress, anxiety, and other health-related conditions in seriously ill patients. Several clinical trials of aromatherapy in patients with cancer have been published with mixed results.
A few early studies have shown that aromatherapy may improve quality of life in patients with cancer. Some patients receiving aromatherapy have reported improvement in symptoms such as nausea or pain, and have lower blood pressure, pulse, and respiratory rates. Studies of aromatherapy massage have had mixed results, with some studies reporting improvement in mood, anxiety, pain, and constipation and other studies reporting no effect.
A study of inhaled bergamot in children and adolescents receiving stem cell transplants reported an increase in anxiety and nausea and no effect on pain. Parents receiving the aromatherapy and parents receiving the placebo both showed less anxiety after their children’s transplants. In a study of adult patients receiving stem cell transplants, tasting or sniffing sliced oranges was more effective at reducing nausea, retching, and coughing than inhaling an orange essential oil.
A small study of tea tree oil as a topical treatment to clear antibiotic-resistant MRSA bacteria from the skin of hospital patients found that it was as effective as the standard treatment. Antibacterial essential oils have been studied to lessen odor in necrotic ulcers.
No studies in scientific or medical literature discuss aromatherapy as a treatment for cancer.
Safety testing on essential oils shows very few bad side effects or risks when they are used as directed. Some essential oils have been approved as ingredients in food and are classified as GRAS (generally recognized as safe) by the U.S. Food and Drug Administration, within specific limits. Eating large amounts of essential oils is not recommended.
Allergic reactions and skin irritation may occur in aromatherapists or in patients, especially when essential oils are in contact with the skin for long periods of time. Sun sensitivity may develop when citrus or other oils are applied to the skin before sun exposure.
Lavender and tea tree oils have been found to have some hormone-like effects. They have effects similar to estrogen (female sex hormone) and also block or decrease the effect of androgens (male sex hormones). Applying lavender and tea tree oils to the skin over a long period of time has been linked in one study to breast enlargement in boys who have not yet reached puberty. It is recommended that patients with tumors that need estrogen to grow avoid using lavender and tea tree oils.
Aromatherapy products do not need approval by the Food and Drug Administration because no specific claims are made for the treatment of cancer or other diseases.
Aromatherapy is not regulated by state law, and there is no licensing required to practice aromatherapy in the United States. Professionals often combine aromatherapy training with another field in which they are licensed, for example, massage therapy, registered nursing, acupuncture, or naturopathy. Some aromatherapy courses for healthcare providers offer medical credit hours and include conducting research.
The National Association for Holistic Aromatherapy (
The Canadian Federation of Aromatherapists (