We shake it on pizzas, pinch it into sauces, soups and salad dressings—oregano is a fundamental flavor for well-seasoned cuisine. Yet the furry-leafed herb has medicinal purposes that may prove more important than the piquant kick it lends to cooking. Oregano oil (Origanum vulgare)—from the hardy perennial that grows in the high, dry Mediterranean mountains, mostly in Turkey and Syria—has potent antibiotic qualities.
According to Cass Ingram, D.O., author of The Cure is in the Cupboard: How to Use Oregano for Better Health (Knowledge House, 2001) and nutritional consultant for Waukegan, Ill.-based North American Herb and Spice, wild oregano oil has proven itself a powerful antibacterial and antifungal agent. Researchers are still discovering the herb's antimicrobial and pharmaceutical properties, he says. "It's got some kind of power we're not accustomed to," Ingram says, "and good research behind it."
Researchers conducted in vitro tests at Georgetown University Medical Center and found oregano oil combated the yeast strain Candida albicans, performing as well or better than the strongest antifungal medicines (Molecular and Cellular Biochemistry, 2001). Tests at Cornell University showed oregano oil works similarly to the powerful antifungal amphotericin B for treating infections. It also matched the properties of most medicines that combat staphylococcus. Human tests have not yet been done.
Ingram's experience with oregano oil is extensive and personal. In the early 1990s, the osteopath found it cured a host of his own chronic ailments, including psoriasis, irritable bowel and stomach disorders. He became a convert.
Not everyone is fully convinced of oregano oil's efficacy, however. Ed Smith, co-owner of Williams, Ore.-based HerbPharm, reports a higher demand for the oil, but would prefer to see more research on it. "Topically, oregano oil is very effective for ringworm, and I'm definitely convinced it's great as a diuretic and expectorant," Smith says. "But as a stimulant for the immune system? I don't know that it is, and those who say it is don't know so."
Retailers and manufacturers also agree wild oregano oil is a profitable product. It's expensive, though, because extracting it is no simple task. Hand-harvested in wilderness areas, the plants must be gathered just after they have gone to seed, when the oil—although there is less of it—is at its peak nutraceutical value. After drying, the leaves—which yield only 1 ounce of oil for every 11/2 pounds of harvested leaves—are distilled with steam to produce the pale yellow oil. Mainly produced in Russia, Bulgaria and Italy, the spicy-smelling substance is stored in drums and shipped to the United States for distribution.
In addition to assorted terpenes, long-chain alcoholic compounds and flavonoids, the principal healing constituents in oregano oil are the phenolic compounds carvacrol and thymol. Both are potent antiseptics, so strong that the same compounds are found in the mainstream products Lysol, Pine-Sol and Chloraseptic, according to Ingram. Researchers in one study found oregano oil to be the single most potent antimicrobial essential oil when tested against six other oils, including lavender, lemon, clove and thyme (Journal of Agricultural and Food Chemistry, 2000).
"If you market oregano raised in Saskatchewan or Costa Rica or Mexico, I'm not interested in it," Ingram says. "The chemistry is totally different. Plus, there's a lot of high-thymol and contaminated stuff on the market now."
Essential oils have been taken for medicinal reasons for millennia. Oregano's recent surge in popularity reflects a return to—not a discovery of—an ancient healing oil. In her Encyclopedia of Essential Oils (Element Books Ltd., 1995), author Julia Lawless notes O. vulgare's ancient medical reputation, ascribing "analgesic, antirheumatic, antiseptic, antispasmodic, antitoxic, antiviral, bactericidal, carminative, diuretic, expectorant, fungicidal, parasiticidal, stimulant and tonic" properties—among others—to the herb.
In its pure form, oregano oil is actually a dermal toxin; it irritates the skin and mucous membranes. Therefore, wild oregano oil must be diluted in olive oil or another carrier before taken internally or applied to skin. Wise consumers will work with a qualified practitioner to determine dosage and schedule for their specific conditions.
Colin Berry is a Guernville, Calif.-based freelance writer and frequent contributor to NPR's All Things Considered.
Natural Foods Merchandiser volume XXIV/number 3/p. 104, 108