Do Essential Oils Heal You?
Chances are you know someone who swears that the essential oils of plants, flowers, and herbs have healing powers. Maybe they rub lavender oil on their temples when feeling stressed or massage aching muscles with peppermint oil. They may even gargle with oregano oil for a sore throat or sniff eucalyptus oil for a stuffy nose.
Marketers who sell essential oils or lotions, soaps, and other products containing them often tout them as a remedy for everything from headaches and muscle pain to sleeplessness and stress. Consumers are buying into these claims, spending more than $1 billion on essential oils in the U.S. alone. Essential oils have been used for centuries as an antidote for an array of physical and mental ailments, but can they really heal or are they just outdated remnants of folk medicine?
An Age-old Practice
Essential oils from the leaves, roots, flowers and the bark of plants were some of the earliest medicines used in ancient Egypt and the Middle East. They were also central to India’s early system of holistic medicine, Ayurveda, and used extensively by Roman and Greek physicians, who shared their expertise with scholars around the world.
Essential oils are extracts of the fragrant part of plants, which are found under the surface of leaves, bark, or peels. These oils contain compounds believed to protect plants from disease, deter hungry insects, and attract pollinators. When aromatic plants are pressed, crushed, or undergo distillation, they release oils retaining the scent and flavor, also referred to as the “essence.” It takes 220 pounds of lavender flowers, for example, to produce approximately one pound of lavender oil.
Essential oils are most commonly used in aromatherapy, a complementary health practice that promotes physical and psychological well-being by diffusing single or blended oils into the air, or applying them directly to the skin, adding them to bathwater, or personal care products such as massage oil or lotions. Inhaling molecules of these extracts or applying them to the skin and allowing them to absorb into the bloodstream is shown to stimulate the olfactory nerve, which sends messages to the limbic system - the part of the brain that controls the formation of memories and various emotions and behaviors. This is believed to trigger physiological responses in the body such as breathing, heart rate, and blood pressure.
Scientists have identified qualities of essential oils that appear to be beneficial to human health. Essential oils have adaptogenic properties, which enhance the body’s adaptive response to physical and emotional stress, and some have been shown to suppress inflammatory reactions in cell tissue. Some essential oils also contain substances capable of inhibiting the spread of harmful microorganisms and acting on the nervous system to subdue pain receptors.
There are numerous anecdotal stories about how different oils can ease stress, induce sleep, aid digestion, and fight infection, but there is no scientific proof to back many of these claims. Research on how essential oils work in the body is mostly limited to lab and animal studies. Even in clinical studies on humans, results have been conflicting and inconclusive, prompting researchers to call for larger, more controlled trials.
Here’s what studies say about the most commonly discussed potential benefits of using essential oils.
Essential oils such as lavender, lemon, rose, chamomile and jasmine are used in many aromatherapy products marketed as mood boosters. Several small studies have tested the effects of these oils and found that they may have a positive impact on mood, but only temporarily. In a study published in the journal of Psycho-neuro-endocrinology, Ohio State University researchers taped cotton balls scented with lavender oil, lemon oil, and distilled water to the noses of 56 volunteers before and after a simulated stress event. Participants were exposed to each of the odors during multiple visits and quizzed about their mood. While the scents showed no effect on heart rate, blood pressure, pain ratings or stress hormones in blood samples of subjects, the lemon oil did appear to enhance their mood, regardless of their expectancies or previous use of aromatherapy. The effects of lavender, however, were no different than water in some of the tests. In several clinical trials, Japanese researchers observed that inhaling the aroma of yuzu, a yellowish-golden citrus fruit, improved heart rate and mood. A small study of a dozen people with depression showed that sniffing the citrus fragrance helped normalize hormone levels more effectively than antidepressants.
Memory and Concentration
British researchers at Northumbria University have conducted a series of studies exploring the effects of rosemary oil and other types of oils on memory and cognitive processing. In a small study in 2012, published in the journal Therapeutic Advances in Psychopharmacology, participants sniffed different concentrations of rosemary aromas and were tested for speed and accuracy in performing a series of tasks. Subjects, especially those who inhaled higher concentrations of the extract, showed improved performance on tasks.
In another study, researchers examined rosemary’s effect on long-term memory. Participants assigned to a rosemary-scented room showed a heightened ability to perform memory-related tasks and complete tasks at set times in the future. Subsequent studies with larger participation universities have also found that rosemary may enhance memory and alertness for adults over 65.
Researchers have also studied the effects of peppermint oil on memory. A study conducted at Wheeling Jesuit University found that smelling peppermint and cinnamon odors left motorists feeling perkier and less frustrated when behind the wheel. In a small study of university students in Iran, those who ingested peppermint oil exhibited increasingly higher rates of energy and muscle memory afterward.
Essential oils such as bergamot, chamomile, frankincense, lavender, lemon, and rose have long been used for promoting relaxation. A 2014 study, published in the journal Evidence-Based Complementary and Alternative Medicine, investigated the effects of several of these oils on the nerves, sleep, and blood pressure of ICU patients receiving angioplasties. Patients in the experimental group who sniffed oils blended with lavender, chamomile, and neroli before and after the procedure showed lower rates of anxiousness and better sleep quality than those in the control group.
Lavender has been shown to have a normalizing effect on levels of the stress hormone cortisol in a few small studies as well as support for brain waves associated with relaxation and deep sleep. In a 2015 study published in the BMC Complementary and Alternative Medicine journal, patients with dementia who inhaled lavender oil experienced decreased agitation, especially in combination with acupressure.
Lotion containing lemon balm oil had a similar effect on patients with dementia in an earlier study in the Journal of Clinical Psychiatry. Patients who used the lotion twice a day for four weeks exhibited fewer signs of agitation, such as throwing objects and screaming. In another small study, inhaling lemongrass oil before a simulated stressful event resulted in reduced tension among volunteers, leading researchers to conclude that “brief exposure to this aroma has some perceived anxiolytic effects.”
Pain and Nausea
Certain essential oils have shown potential for providing temporary relief from headaches, muscle pain, and nausea. A 2012 study found that inhaling lavender oil for just 15 minutes eased the severity of migraines for up to two hours among a small group of patients. Another study found that patients with tension headaches who rubbed peppermint oil diluted with alcohol onto their temples experienced less intense pain.
Massaging a few drops of lavender, rose, cinnamon, and clove oil diluted with almond oil into the abdomen of female subjects prior to their period resulted in less painful menstrual cramps, according to one study.
Favorable studies on the effects of lavender and ginger oil in patients following surgery have prompted some hospitals and clinics to use them for pain tolerance and nausea. In one study published in the Anesthesia Analgesia journal, more than 300 patients who inhaled a blend of ginger, spearmint, peppermint, and cardamom oil after surgery reported lower levels of nausea than those in the control group.
In another recent study, women receiving chemotherapy for breast cancer showed improvement in acute nausea after inhaling ginger oil.
Preliminary studies show that certain oils like tea tree and oregano may help support immune health, which interests researchers looking for ways to counter the growing antibiotic resistance crisis.
A small study by British and Australian researchers tested the effects of tea tree oil on drug-resistant Staphylococcus aureus (MRSA) in the lab and found it to be as effective as the standard ointment for eliminating the bacteria from the skin of patients.
A Polish study in the journal Molecules showed that basil and rosemary oil were capable of inhibiting the growth of some strains of drug-resistant E.coli in samples of the bacteria taken from patients. Researchers have also discovered that eucalyptus oil contains compounds that may “have antimicrobial effects against many bacteria,” including viruses and fungi, according to a study in the Alternative Medicine Review, and may be beneficial for respiratory problems. Its primary compound, cineole, was shown to help clear airways of bacteria and ease symptoms such as congestion and head pressure in a German study.
Essential oils are challenging to study because they are not standardized. Unlike synthetic drugs, which are produced under the same conditions, the composition of these plant extracts often vary based on a variety of factors, including weather conditions, seasons and even the time of day they were harvested. Because they are often used with other complementary health approaches like massage therapy and acupuncture, it can be difficult to determine their actual effect. There is also the expectancy factor to consider. If you believe that sniffing a scent will have a certain effect on you, your expectancy can result in placebo benefits, scientists say.
While there is no evidence that essential oils can heal you, they may help to support physical and mental wellness when used as directed and in moderation. Safety testing has found few adverse effects when using essential oils, except for pregnant or breastfeeding women.
Because essential oils are highly concentrated, they should be handled with caution and always diluted with a carrier oil before any topical application. Sun sensitivity can occur when citrus or other oils are applied before going out in the sun, and some oils have been known to cause skin irritation and reactions in certain people.
Essential oils are not regulated by the FDA, so it’s best to talk to your doctor before using them regularly for medicinal purposes.