What is aromatherapy?
Aromatherapy is the use of essential oils from plants to improve the mind, body, and spirit. It is used by patients with cancer to improve quality of life and reduce stress, anxiety, pain, nausea, and vomiting caused by cancer and its treatment. Aromatherapy is often used with other complementary treatments like massage therapy and acupuncture, as well as with standard medical treatments, for symptom management.
Essential oils are the fragrant (aromatic) part found in many plants, often under the surface of leaves, bark, or peel. The fragrance is released if the plant is crushed or a special steam process is used.
There are many essential oils used in aromatherapy, including those from Roman chamomile, geranium, lavender, tea tree, lemon, ginger, cedarwood, and bergamot. Each plant's essential oil has a different chemical make-up that affects how it smells, how it is absorbed, and how it affects the body.
Essential oils are very concentrated. For example, it takes about 220 pounds of lavender flowers to make about 1 pound of essential oil. The aroma of essential oils fades away quickly when left open to air.
The chemical compounds in essential oils can change as they get older. Many essential oils do not have an expiration date.
How is aromatherapy given or taken?
Aromatherapy is used in several ways.
- Indirect inhalation: The patient breathes in an essential oil by using a room diffuser, which spreads the essential oil through the air, or by placing drops on a tissue or piece of cotton nearby.
- Direct inhalation: The patient breathes in an essential oil by using an individual inhaler made by floating essential oil drops on top of hot water.
- Massage: In aromatherapy massage, one or more essential oils is diluted into a carrier oil and massaged into the skin.
Essential oils may also be mixed with bath salts and lotions or applied to bandages.
There are some essential oils used to treat specific conditions. However, the types of essential oils used and the ways they are combined vary, depending on the experience and training of the aromatherapist.
Have any preclinical (laboratory or animal) studies been done using aromatherapy?
In laboratory studies, tumor cells are used to test a substance to find out if it is likely to have any anticancer effects. In animal studies, tests are done to see if a drug, procedure, or treatment is safe and effective in animals. Laboratory and animal studies are done before a substance is tested in people.
Laboratory and animal studies have tested the effects of essential oils. For information on laboratory and animal studies done using essential oils, see the Laboratory/Animal/Preclinical Studies section of the health professional version of Aromatherapy With Essential Oils.
Have any clinical trials (research studies with people) of aromatherapy been done?
Clinical trials of aromatherapy have studied its use in the treatment of anxiety, nausea, vomiting, and other health-related conditions in cancer patients. No studies of aromatherapy used to treat cancer have been published in a peer-reviewed scientific journal.
Studies of aromatherapy have shown mixed results. There have been some reports of improved mood, anxiety, sleep, nausea, and pain. Other studies reported that aromatherapy showed no change in symptoms.
Studies on anxiety and depression
- A trial of 103 cancer patients studied the effects of massage compared to massage with Roman chamomile essential oil. Two weeks later, a decrease in anxiety and improved symptoms were noted in the group that had massage with essential oil. The group that had massage only did not have the same benefit.
- Another study of 58 patients with various cancers who completed six aromatherapy sessions showed a decrease in anxiety and depression compared with before the sessions began.
- A randomized controlled trial studied the effects of inhalation aromatherapy on anxiety during radiation therapy. There were 313 patients randomly assigned to either lavender, bergamot, or cedarwood essential oils. There were no differences reported in depression or anxiety between the groups.
Study on sleep
- Newly diagnosed patients with acute myeloid leukemia who were hospitalized to receive intensive chemotherapy inhaled an essential oil through a diffuser overnight for 3 weeks. Patients were given the choice of lavender, peppermint, or chamomile. Improvement was reported in sleep, tiredness, drowsiness, lack of appetite, depression, anxiety, and well-being.
Study on dry mouth
- Radioactive iodine may cause damage to salivary glands. Increased saliva production during treatment may decrease damage to salivary glands. In a randomized controlled trial, patients who inhaled a mixture of lemon and ginger essential oils had increased saliva production compared with the placebo group.
Studies on nausea and vomiting
- A study of inhaled ginger essential oil in women receiving chemotherapy for breast cancer somewhat decreased acute nausea, but did not lessen vomiting or chronic nausea.
- In a study of adult patients at the time of stem cell infusion, tasting or sniffing sliced oranges was more effective at reducing nausea, retching, and coughing than inhaling an orange essential oil.
Study on aromatherapy in children
Aromatherapy is used or claimed to be useful for a variety of childhood symptoms and conditions. When used safely, aromatherapy can help children feel calmer and sleep better.
- A study of aromatherapy inhaled by children and adolescents undergoing stem cell transplant infusions compared essential oil from the peel of bergamot (a type of orange from trees grown in Italy) with a pleasant-smelling shampoo that did not contain essential oils. Bergamot oil is used in aromatherapy to relieve depression, anxiety, and poor digestion. The placebo-controlled, double-blind, randomized trial in 37 children and adolescents found that aromatherapy was not effective in reducing nausea, anxiety, or pain.
Studies on procedure-related symptoms
- Women having breast biopsies were randomly assigned to receive lavender-sandalwood or orange-peppermint essential oil drops placed on a felt tab and attached to their hospital gown or to no scent on the felt tab. Women who received the lavender-sandalwood aromatherapy tab had less anxiety than women who received the orange-peppermint aromatherapy tab or no scent tab.
- In a study of inhaled lavender essential oil, eucalyptus essential oil, or no essential oil in cancer patients having needles inserted into a central venous port catheter, patients who inhaled lavender essential oil reported less pain.
- A randomized controlled trial compared aromatherapy, music therapy, a combination of both, or a placebo in women with breast cancer before and after they had a mastectomy. The aromatherapy group received a mixture of lavender, bergamot, and geranium essential oils, while the music group was given a choice of music styles. The combination of treatments was found to be more effective in lessening pain and anxiety than either treatment alone.
Have any side effects or risks been reported from aromatherapy?
Safety testing on essential oils shows very few side effects or risks when they are used as directed. Most essential oils have been approved as ingredients in food and fragrances and are labeled as GRAS (generally recognized as safe) by the U.S. Food and Drug Administration (FDA). Swallowing large amounts of essential oils is not recommended.
Allergic reactions and skin irritation may occur when essential oils are in contact with the skin for long periods of time. Sun sensitivity may occur when citrus or other essential oils are applied to the skin before going out in the sun.
Lavender and tea tree essential oils have been found to 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 essential oils to the skin over a long period of time was linked in one study to breast growth in boys who had not yet reached puberty.
Is aromatherapy approved by the FDA for use as a cancer treatment in the United States?
Aromatherapy products do not need FDA approval.
Aromatherapy is not regulated by state law, and there is no licensing required to practice aromatherapy in the United States. Practitioners often combine aromatherapy training with another field in which they are licensed, for example, massage therapy, nursing, acupuncture, or naturopathy.
The National Association for Holistic Aromatherapy (www.naha.org) and the Alliance of International Aromatherapists (www.alliance-aromatherapists.org) are two organizations that have national educational standards for aromatherapists. A list of schools that offer certificate programs approved by NAHA can be found at https://naha.org/index.php/education/approved-schools/.
The Canadian Federation of Aromatherapists (www.cfacanada.com) certifies aromatherapists in Canada. For a list of international aromatherapy programs, see the International Federation of Aromatherapists website (www.ifaroma.org/).