by Dr. Josh Axe
The ancient Chinese understood the power of essential oils as well. They began studying aromatics as early as 2700 BC and integrated oils into their elaborate medical system. A practitioner might use a yang essential oil, like ginger, which has warming properties, to aid in digestion and help clear dampness caused by candida or a cold, for instance.
In ancient Greece, Hippocrates prescribed aromatherapy to enhance the health benefits of massage and documented the action of two hundred different herbs. Others contributed to our essential oils knowledge base as well. Aristotle’s successor, Theophrastus, for instance, investigated how specific scents affected emotions.
Essential oils are also an integral part of Ayurvedic medicine, and they are referenced more than 250 times in the Bible! In fact, the book of Exodus contains a recipe for the holy anointing oil—a blend of myrrh, cinnamon, calamus, cassia, and olive oil—that was routinely used for healing.
And these healing oils have been used in more recent history, as well. In 1910, the French chemist René-Maurice Gattefossé was working in a perfume plant when he burned his hand. He plunged it into the nearest vat of liquid, which turned out to be lavender oil. He felt instant relief—and his skin healed quickly, with minimal scarring. He then began his advanced studies on essential oils and wrote the groundbreaking aromatherapy textbook Gattefossé’s Aromatherapy. In it, he shares the recipe for a disease-fighting blend called the Four Thieves—vinegar infused with a variety of herbs and spices, including sage, clove, rosemary, and wild marjoram. As legend has it, the antibacterial and antiviral formula was discovered by thieves in Europe during the seventeenth-century plague. They were robbing the dead and sick without becoming ill themselves. When they were caught, the authorities offered to pardon them in exchange for the formula. Modern versions of the Four Thieves recipe typically include clove, sage, thyme, rosemary, and garlic.
Why would an oil from a plant help you fight off illnesses? It’s actually pretty simple. Plants are vulnerable to, and must fight off, many of the same pathogens that cause human disease, including viruses, bacteria, fungi, and parasites. So when you inhale, apply, or ingest their essential oils, your body utilizes the plant’s protective compounds—and those substances work with your innate disease-fighting power to create a more powerful defense. Oregano and thyme are great examples. They contain compounds that naturally repel viruses, bacteria, and parasites—so when we use their essential oils, they bolster our ability to fight pathogens as well.
As a result, plant oils can be as helpful for modern health conditions as they were in older times. In fact, at least 8,500 studies have examined essential oils over the past 165 years. Many of my patients have used them in place of prescription medications, which makes a lot of sense. Not only are oils less expensive, they don’t have toxic side effects like most medications do (although some oils can be dangerous if you don’t use them correctly). What’s more, they can have similar biological effects. Peppermint oil, for instance, has been proven to be effective at naturally treating irritable bowel syndrome (IBS). One study published in the journal Digestive and Liver Disease found a 50 percent reduction in IBS symptoms in 75 percent of patients who used it.5 And in addition to the uses of frankincense I mentioned earlier, this “king of oils,” as it’s often called, is beneficial for those with chronic stress and anxiety—probably because it contains high doses of alpha-pinene, a substance that affects GABA, a brain chemical involved in mood regulation.
There’s another way essential oils can bolster your overall health: You can use them in place of toxic household cleaning products and personal care products. Chelsea and I use lemon oil and tea tree oil, mixed with a few ounces of water and vinegar, as an effective and clean-smelling spray for our kitchen countertops. And when it comes to caring for your appearance, essential oils are preferable. Tea tree oil can effectively get rid of acne,6 for example, and peppermint oil is a great way to freshen your breath.7
Coming up, I’ll explain how essential oils can affect your body, as well as the benefits of a dozen of my favorite oils, and how to find the highest-quality options.
Essential oils provide many types of healing
Plants, like humans, have protective chemicals built into their systems to help them fight off bugs, pests, fungi, and other dangers. Those natural chemicals are what make vegetables and fruits such an indispensable part of our daily diets. Essential oils are similar, except they contain highly concentrated quantities of the most protective compounds in each plant. Created through a process of distillation, which captures the healing essence of each plant, the liquid in every small vial has tremendous therapeutic potential. A single 15-milliliter bottle of rose essential oil, for instance, contains 65 pounds of distilled and condensed rose petals.
Because essential oils are so concentrated, they have a robust aroma. Remember when I explained the health benefits of terpenes, the scent chemicals found in hemp, back in chapter 7? Essential oils contain terpenes as well, and these compounds are responsible not only for the oils’ relaxing and invigorating scents, but also for many of their medicinal properties. When you inhale an essential oil, terpene molecules plug into scent receptors in your nose, triggering effects that are relayed from your nervous system to your brain, where the tiny terpene molecules are able to cross the blood-brain barrier. The molecules also make their way to your lungs, where they’re absorbed into your bloodstream. A single whiff, in some cases, is enough to trigger healthy emotional or physical changes. And when you apply oil topically, you not only inhale its effects, you also absorb the therapeutic molecules through your skin and into your bloodstream.
Natural healers knew this four thousand years ago, and practitioners of TCM and Ayurveda have been using aromatherapy as a cornerstone of treatment ever since. As evidence of essential oils’ effectiveness piles up, Western healthcare professionals are taking notice. A number of hospitals around the country, from Nebraska to New Jersey, are using the substances to relax patients and staff. One study, published in Evidence-Based Complementary and Alternative Medicine, looked at the effect of inhaled lavender oil on patients in the intensive care unit. Researchers found that the treatment relieved patients’ stress—which is typically high in ICU patients—and improved their sleep, an essential aspect of healing.8 And that’s just one example of hundreds of studies that are beginning to reveal why we all need essential oils in our medicine cabinets.
The 12 essential oils you can’t live without
Essential oils are extremely versatile. You can diffuse them into the air, put a drop or two in the bathtub, rub a dab on your skin, or ingest a few drops, usually with water or a carrier oil, like coconut or olive oil. Oils that come from commonly consumed herbs, spices, roots, and berries—like ginger oil, turmeric oil, lemon oil, and peppermint oil—are safe to take orally; the common therapeutic dosage in medical studies is 1 or 2 drops, or approximately 60 milligrams.
But there are some caveats when using essential oils. Tree oils, including arborvitae, birch, cedarwood, cypress, eucalyptus, tea tree, white fir, and wintergreen, are dangerous to ingest. Other oils might cause a skin reaction if you apply them topically (I offer guidelines for safe usage below). If you experience any side effects, like dizziness or nausea, when using an oil, stop using it immediately. One more thing: It’s extremely important to buy a high-quality product. Synthetic oils are worthless at best and unhealthy at worst. Make sure the package says the oil is certified USDA organic, 100 percent pure, therapeutic grade, and indigenously sourced.
Here are twelve of my favorite oils, along with the safest, most effective ways to use them. I’m thrilled to share them with you, so you can take advantage of some of the most beneficial remedies known to man.
Lavender. Recognized for centuries for its therapeutic and cosmetic value, lavender is the most widely used essential oil in the world. In a randomized, controlled trial, German researchers found that lavender oil capsules (they’re available over the counter) actually work better
than paroxetine, a commonly prescribed anti-anxiety drug, to treat generalized anxiety disorder.9 Inhaling lavender oil has also been shown to relieve headaches10 and improve sleep.11 What’s more, it’s a natural antioxidant, so it helps prevent and reverse disease, and, according to a study in Phytomedicine, it actually bolsters the activity of some of the body’s most potent antioxidants, including glutathione, catalase, and superoxide dismutase.12 Putting a few drops in a diffuser every day may help you stay well and achieve better health overall. Lavender oil can also help calm acne and erase age spots. Just mix 3 to 4 drops with ½ teaspoon of a carrier oil, like coconut, jojoba, or grapeseed oil, and massage the mixture into your skin. Precautions: Lavender oil is safest and most effective when you inhale the scent or apply it topically. Don’t use it in addition to a prescription or over-the-counter sleep aid, as it can exacerbate the sedative effects. Because it can relax muscles and affect hormones, avoid it in the third trimester of pregnancy—and use only infrequently in young children.
Frankincense. As you may remember, this essential oil plays an important role in the Bible. Along with gold and myrrh, it was one of the gifts the three wise men brought to the infant Jesus. In those days, it was used to strengthen the immune system, and studies today confirm its effectiveness in that regard.13 So you can use it as part of your health regimen to fight colds and other viral and bacterial infections. With its lemony, woodsy scent, this ancient oil’s numerous health benefits are due to a wide variety of terpenes, including boswellic acid, an anti-inflammatory that protects the health of your cells. I’ve already mentioned frankincense’s anticancer properties. It has been shown to inhibit the aggressiveness or even kill breast cancer cells,14 bladder cancer cells,15 and skin cancer cells.16 What’s more, animal research suggests that frankincense oil improves memory and learning, and can improve cognition in those with Alzheimer’s.17 It also seems to be helpful for gut-related issues, like leaky gut, colitis, Crohn’s disease, and irritable bowel syndrome.18 To use frankincense for health, add 3 or 4 drops of oil to a diffuser or put a few drops of oil in a pot of boiling water. Frankincense can also improve skin, reducing pore size, preventing wrinkles, and even lifting and tightening skin. Mix 6 drops of oil in 1 ounce of unscented oil and apply it directly to the skin. It’s most effective when you inhale the scent or apply it topically, but you can ingest small amounts as well.
Oregano. Hippocrates used oregano for treating respiratory and digestive diseases, and ancient Greeks used it to treat skin infections, sore throats, wounds, and viruses. In TCM, it has been used for thousands of years to treat diarrhea, parasites, and fungal infections—and many of those ancient uses are being validated today. Researchers are studying this oil as an alternative to antibiotics, which, as I explained in chapter 1, are dangerously overprescribed, a problem that is leading to widespread antibiotic resistance. Oregano oil—and particularly carvacrol, its most abundant chemical—has been shown to effectively inhibit a number of different viruses, including herpes, respiratory syncytial virus, and rotavirus.19 To use it as a natural antibiotic or antiviral, put 4 drops in 1 teaspoon of olive oil and take it twice a day for ten days. Oral oregano oil was also able to get rid of intestinal parasites, according to a study in Phytotherapy Research,20 and lower cholesterol, according to research published in Evidence-Based Complementary and Alternative Medicine.21 Of all the essential oils, oregano is the best at treating athlete’s foot.22 To use it, add 3 drops to an antifungal powder made of 1 teaspoon of bentonite clay and ½ teaspoon of cayenne powder, then rub the powder onto the affected area. It is also great at getting rid of mold around your home, and can limit the survival of common food-borne pathogens, like listeria, salmonella, and E. coli.23 To use it as a cleaning product, just add 5 to 7 drops to a spray bottle filled with water. Precautions: Don’t take oregano oil orally for more than fourteen days in a row. Pregnant women shouldn’t use it at all.
Tea tree. Derived from the plant Melaleuca alternifolia, tea tree oil has been used for thousands of years by the indigenous Bundjalung Aborigines of Australia, who use the leaves of the plant to treat common illnesses. The oil is essential to have on hand today during flu season, since it has potent antiviral properties. Inhaling the scent of the oil, for instance, can help you fight respiratory tract infections and coughs,24 and diffusing it through the air may inactivate airborne flu virus particles.25 Put 5 drops in a diffuser or boiling water, or inhale tea tree oil directly from the bottle. Tea tree oil has become popular around the world today because it is a powerful disinfectant and is effective for treating skin conditions. Indeed, it has the ability to inhibit the growth of bacteria and treat fungal infections, like athlete’s foot and jock itch.26 Mix 10 drops with 1 teaspoon of coconut oil and apply it to the affected area twice a day. It can also reduce acne when applied topically.27 Mix 5 drops of tea tree oil with 2 teaspoons of raw honey, rub onto your face, and rinse off after one minute. And tea tree oil shampoo (there are a number on the market) has been shown to significantly reduce dandruff.28 Precautions: Tea tree oil should never be ingested.
Peppermint. One of the oldest herbs used for medical purposes, peppermint’s use dates to ancient Egypt, China, Japan, and Greece. It’s also one of the most versatile oils and can help with everything from muscle aches to seasonal allergy symptoms. I explained earlier in the chapter that peppermint oil can relieve symptoms of irritable bowel syndrome. That’s because it relaxes the muscles in the intestines,29 and it can do the same with the muscles in the rest of your body. Because peppermint oil contains menthol, which increases blood flow and produces a cooling sensation, it also acts as an analgesic. To use it as a rub for sore muscles, mix 3 or 4 drops of peppermint oil with 1 teaspoon each of coconut oil and eucalyptus oil. Or add 5 to 10 drops to bathwater and soak in it. When you apply a drop or two to your forehead or temples, its refreshing scent can help ease migraines, too, according to a randomized, controlled trial published in the International Journal of Clinical Practice.30 Similarly, inhaling peppermint oil can unclog stuffy sinuses and may reduce seasonal allergy symptoms. Put a few drops in a diffuser or boiling water, or apply topically to your temples, chest, and back of neck. Finally, you can use the scent to support weight loss, because peppermint suppresses cravings and improves digestive health.31 Precautions: Peppermint oil can be inhaled, used topically, or taken orally, although you shouldn’t ingest more than a drop or two. I also don’t recommend using it on infants’ skin, or on the skin of women who are pregnant or nursing.
Lemon. Ayurvedic medicine practitioners have been using lemon essential oil to treat a wide spectrum of health conditions for at least a thousand years. Made by cold-pressing the nutrient-dense peel, which contains a variety of terpenes and fat-soluble nutrients, the oil has a scent that can relieve nausea—studies have shown it’s effective in pregnant women32—and constipation.33 It can also decrease stress and anxiety, according to both animal34 and human studies.35 Moreover, ingesting lemon oil can promote detoxification. A 2016 animal study found that lemon oil reduced the aspirin-induced liver and kidney damage in rats.36 To promote detoxification, add 1 or 2 drops to a glass of water daily for a week. Thanks to its strong antioxidant and anti-aging effects, lemon oil also protects the skin—and it can be helpful for everything from insect bites to athlete’s foot.37 Put 12 or so drops in ¼ cup of jojoba or coconut oil and apply to the affected area. Lemon oil is also useful as a home cleaning product, because it contains limonene and beta-pinene, two known antimicrobial agents. Add 40 drops of lemon oil and 20 drops of tea tree oil to a 16-ounce spray bottle filled with water and a dash of white vinegar. Precautions: Take no more than a drop or two a day orally. If you’re applying it to your skin, test it on a small patch beforehand to make sure you don’t develop a reaction. Because it can make your skin sensitive to sunlight, avoid direct sun for twelve hours after using.
Rosemary. The ancient Egyptians, Romans, and Greeks all considered rosemary sacred, and it was widely used to cleanse the air and prev
ent illnesses from spreading. Although the scent can’t kill airborne pathogens, it is great for your brain. A study in the International Journal of Neuroscience found that inhaling the scent of rosemary oil can enhance memory and concentration38—and a paper in Psychogeriatrics showed that it may improve cognitive function in people with Alzheimer’s.39 Inhaling the scent can also reduce levels of the stress hormone cortisol,40 which is helpful for anyone who is under a lot of stress or who is struggling with adrenal fatigue. Equally exciting, rosemary oil contains carnosol, which holds promise for its ability to kill cancer cells while leaving the healthy cells nearby unscathed—the gold standard for cancer treatments.41 As of yet, there are no guidelines on how to use it for cancer prevention. With an oxygen radical absorbance capacity (ORAC) score of 11.07, rosemary has the same off-the-charts ability to fight free radicals as goji berries, so it’s great for protecting your body from age-related disease as well. Finally, a study in the journal SKINmed found that rosemary oil increased hair growth in people with hair loss as well as the prescription drug minoxidil.42 Precautions: When using topically, always dilute with a carrier oil, like jojoba, to avoid skin sensitivity. Don’t use the substance on children, and don’t take internally.
Clary sage. Medieval physicians called this herb “clear eye” (the Latin word clarus means “clear”) for its ability to heal vision-related issues. In TCM, sage is used to strengthen the kidneys, adrenals, and women’s reproductive organs. Long used as a folk remedy for relieving menstrual cramps (combine 5 drops of clary sage oil with 5 drops of jojoba oil and massage it into your abdomen), it also can be effective at relieving pain and anxiety for women during childbirth, according to a study by researchers in the United Kingdom.43 Inhaling the oil’s scent can also lower cortisol, the stress hormone, and improve mood in people diagnosed with depression, according to a study in the Journal of Phytotherapy Research.44 Since stress is a major cause of insomnia, diffusing some clary sage oil into your bedroom (or putting 5 drops into your pre-bedtime bath) might help you sleep better. Moreover, a double-blind, randomized controlled trial found that clary sage aromatherapy can reduce blood pressure when you’re under stress.45 It also contains antifungal and antiseptic properties and boosts eye, hair, and skin health. Precautions: Avoid during pregnancy, because it can cause uterine contractions, and don’t give it to infants or toddlers. Don’t use it during or after drinking alcohol, as it can exacerbate alcohol’s sedative effects. And don’t ingest more than a drop or two.