It would be delightful to think that essential oils are simply gifts from nature to humankind. Sensuous, stimulating compounds concocted by Mother Gaia solely for our enjoyment. Indeed when you think about where essential oils are most commonly employed (in cuisine, in aromatherapy and massage) it certainly may seem so. Yet if the natural sciences teach us anything it is that everything in nature has a purpose, and essential oils are no different. They are in fact natural bug and microbe repellents, part of a plant’s defensive system.
Most essential oils are in fact toxins of various types, stored in special structures or glands so they won’t poison the plants that produced them. Their purpose is identical to that of the bitter-tasting alkaloids found in so many greens: to poison, dope, or otherwise deter an animal that might try to eat them. One taste of raw, undiluted essential oils is enough to prove the point. Ever tried chewing a mouthful of fresh-picked mint leaves? A vanilla bean? How about some cloves? The effect is far from pleasant.
Concentrated and purified, essential oils can be downright dangerous. Many like oregano oil are irritating or actually damaging to skin and lungs, which is why they need to be diluted before they’re used. Naturally essential oils make great summer bug repellent for humans as well as plants, provided they’re treated with as much deference as man-made repellents. Modern-day marketing of natural foods and medicines has instilled in us an idea that nothing that’s made by nature can hurt you, a notion that our forebears (to say nothing of anyone who’s every been hit with pepper spray) would find bizarre to say the least. Nature’s toxins can be every bit as potent as our own, even if they do taste a lot better in spaghetti sauce.