As I was preparing for the recent birth of my second child, I spent some time getting the layette clothes out of storage, setting up the changing table and crib, and running through a mental “refresher course” about how to care for a newborn. While I did this, I had a curious sensation of “smelling” eucalyptus strongly in my mind, a phantom scent that came from memories triggering the olfactory area of my brain.
Anyone who has been in a florist shop with dried flower arrangements knows the distinctive, sharp smell of eucalyptus branches. When my son was born, I received a flower arrangement that smelled so strongly of eucalyptus that I had to put it outside.
I also have a memory of eucalyptus from my own childhood. When my younger brother was an infant, my mother put a steam vaporizer in his room when he was sick and rubbed his tiny chest with Vicks VapoRub, which contains a eucalyptus compound. Now I strongly associate the scent of eucalyptus with infants.
The pungent aroma of eucalyptus (Eucalyptus globulus) comes from many of its components, but by far the strongest and most distinctive is 1,8 cineole, commonly known as eucalyptol. Eucalyptol is part of a large group of aromatic, fat-soluble phytochemicals called terpenes, which are major components of all essential oils. It’s found in many herbs that have distinctive aromas, including basil, cajeput, cinnamon, lavender, nutmeg, peppermint, rosemary, and tea tree. Eucalyptol relaxes the airways, soothes sore throats, and opens congested sinuses and nasal passages—the reason it’s in products such as Vicks VapoRub.
Menthol-eucalyptus chest poultices and cough drops have been used for hundreds of years, and scientists agree that they’re effective. A 1996 study at the University of Vienna shows that eucalyptol is well absorbed into the blood by breathing the vapors. The peak concentration occurs after approximately eighteen minutes, so it makes sense to rub on a salve or dissolve a eucalyptus lozenge in your mouth and breathe in the vapor over time.
Luckily, my son hasn’t ever had a bad cough, but eucalyptol and related phytochemicals came to his rescue in another way. When he was three weeks old, I took him for a routine checkup. He had some diaper rash, which was aggravated by the September heat. It didn’t seem to bother him, but the pediatrician mentioned that in newborns such rashes can be caused by a yeast infection and can get worse. She wrote me a prescription for an antifungal medication.
Instead of filling the prescription, I went home and mixed some tea tree oil into a basic beeswax/almond oil salve. Tea tree (Melaleuca alternifolia) has a distinctive aroma not unlike eucalyptus, largely because of its eucalyptol content. The oils of the tea tree and cajeput tree (M. leucadendron) have long been used as topical antiseptics in Australia and Southeast Asia. Studies have consistently shown that essential oils from these species control the growth of many types of bacteria and fight many fungi, including Candida albicans, a common cause of diaper rash.
I put the tea tree salve on at every diaper change, and in three days the rash was completely gone and never returned—on my son, that is. I got a fungal infection on my right thumbnail, which I later realized was related to my diaper-changing technique. So I put a mixture of tea tree oil and cinnamon leaf oil directly on my nail twice a day, and the infection eventually healed, although not as quickly as my son’s diaper rash. I hope that my daughter won’t have these problems, but if she does, I know which herbs to use.
Note that essential oils of eucalyptus, cajeput, tea tree, and mints (or menthol) should not be swallowed because of potential side effects, such as liver damage and difficulties breathing. Cough drops, mouthwashes, and other similar products contain small, nontoxic amounts of these essential oils, but amounts more than 1/4 teaspoon can be harmful, especially to children and small pets. To be on the safe side, don’t allow infants or small children to breathe the vapors from the pure oils for an extended period.
Jiager, W., et al. “Pharmacokinetic studies of the fragrance compound 1,8-cineol in humans during inhalation.” Chemical Senses 1996, 21:477–480.
Raman, A., et al. “Antimicrobial effects of tea- tree oil and its major components on Staphylococcus aureus, Staph. epidermidis and Propionibacterium acnes.” Letters in Applied Microbiology 1995, 21:242–245.
Schulz, V., et al. Rational Phytotherapy: A Physician’s Guide to Herbal Medicine. 3rd ed.; 1st English ed. Heidelberg: Springer-Verlag, 1998.
C. Leigh Broadhurst holds a doctorate in geochemistry and is a nutrition consultant in Clovery, Maryland.
James Duke is a member of the Herbs for Health Editorial Advisory Board. His most recent book is The Green Pharmacy (Rodale, 1997).