Oil of Oregano Research and Studies

Compiled by Bee Wilder

• The book entitled Beyond Antibiotics: Healthier Options for Families, by Michael A. Schmidt, Lendon H. Smith and Keith W. Sehnert, has an entire section devoted to the antimicrobial (antibacterial, antifungal and antiviral) efficacy of essential plant oils.
  
  In this section they state that “one of the advantages essential oils have over antibiotics is that bacteria do not develop resistance to essential oils.” Many essential oils exert their antibacterial effect by interfering with the bacteria’s ability to breathe.
  
  On the other hand, antibiotics interfere with the life cycle, or metabolism, of bacteria, but since bacteria are very crafty creatures, they change their chemistry and genes, which makes the antibiotic less effective the next time it is used. As a result, new generations of antibiotics will need to be developed to stay ahead of these organisms. Additionally, “another advantage to essential oils is that some actually stimulate immune function.”
  
  Drs. E. Gildemeister and F.R. Hoffmann are referenced in the book as testing the antimicrobial efficacy of certain essential oils as compared to a medium, phenol. Phenol is an antiseptic substance found in Lysol, Pinesol and Chloraseptic throat spray. The findings were quite a surprise to the investigators. Oil of oregano was the most potent antimicrobial essential oil tested by the investigators, as it proved to be 21 times stronger than the medium.
   
• Volume 18 of the British Naturopathic Journal included an article entitled “Kill and Cure: The Healing Properties of Wild Oregano Oil.” In the article, David Potterton, ND summarized the findings of the world’s foremost expert on oil of oregano, Dr. Cass Ingram. According to Dr. Ingram, “oregano is the Rolls Royce of natural antiseptics”. It is, for example, far more active against noxious urinary pathogens than the typically relied upon natural compounds such as garlic, goldenseal and echinacea.
   
• The active ingredient, carvacrol, acts directly upon the mucous membranes of the urinary tract and bladder. It offers the unique advantage of destroying both urinary bacteria as well as yeasts, something that standard antibiotics fail to achieve.” In addition, according to the article, readers should get their hands on a copy of Dr. Ingram’s book The Cure is in the Cupboard: How to use Oregano for Better Health. 
  
  One of Dr. Ingram’s predecessors, renowned scientist H. Martindale, documented that the essential oil of oregano was the most powerful plant-derived antiseptic known. This was back in 1910 when oregano was commonly used to treat illness.  Mr. Martindale demonstrated that oregano was 26 times more active as an antiseptic than phenol, a powerful disinfectant used to sterilize hospital equipment.

• In 1977, at the Second International Congress of Phytotherapy and Aromatherapy Conference in Monaco, a French doctor named Belaiche unveiled his oregano index, which uses oregano oil as the base reference for comparing the bactericidal action of other substances. The reason he chose oregano oil was because he determined by rigorous laboratory experimentation that out of all natural essential oils, oregano was the closest to an ideal antibacterial agent.
  
  Belaiche used the analytical technique of Schroeder and Messing, who measured in millimeters the “halo” of bacterial inhibition caused by specific essential oils in a bacterial culture medium maintained in petri dishes. He tested the ability of essential oils to inhibit bacterial growth as well as to kill bacteria.
  
  Belaiche chose to use bacterial cultures from sick persons rather than cultures grown in laboratories. He tested essential oils on up to 90 different types of bacteria.  Based on these experiments, Belaiche and other French doctors developed an “Aromatogramme,” a chart which measures the halo of inhibition caused by different essential oils on specific bacterial cultures.
  
  After the studies had been completed, Belaiche concluded that “This aromatic essence (oregano) is almost always the leader. Among the most active oils oregano is the ‘best of the best.’ The essential oil of oregano has always provided me with amazing results in treating infectious diseases. Besides oregano oil’s bactericidal action, it also prevents spasms, convulsions and nervous disorders.  In my estimation, the antispasmodic qualities help to synergize its wonderful antiseptic powers, which comfort me every time I prescribe it for my patients.” For the complete guide to aiding numerous ailments with oregano, including allergies, asthma, bronchitis, candidiasis, colds, cold sores, diarrhea, the flu, gastritis, psoriasis, sinusitis and dozens of others, consult Dr. Cass Ingram’s book The Cure is in the Cupboard.
   
• In the article “A Serenade for Marinade” published July 5, 1999, in the Knoxville News (Health and Science section), Dr. F. Ann Draughon, a University of Tennessee microbiologist, studied the effects of herbs on food safety.  Dr. Draughon found that oil of oregano was the most effective at killing all pathogens tested against, including nine food-borne microbes: Listeria monocytogenes, Staphylococcus aureus, Escherichia coli (commonly known as E-coli), Yersinia enterocolitica, Pseudonomas aeruglinosa, Lactobacillus plantarum, Aspergillus niger, Geotrichum and Rhodotorula.
   
• The Tennessee Food Safety Initiative is a research program jointly supported by the U.S. Food and Drug Administration (FDA) and the UT Agricultural Experiment Station.  Has Oregano been tested and evaluated by the U.S. Department of Agriculture? Yes. Oregano had 3 to 20 times higher antioxidant activity than the other herbs studied. Researchers at the U.S. Department of Agriculture have determined that herbs are higher in antioxidant levels than fruits, vegetables and even spices such as garlic. Shiow Y. Wang, a biochemist at the USDA’s Beltsville Agricultural Center in Beltsville, Maryland, stated in the November issue of the Journal of Agricultural and Food Chemistry that the herb “oregano had 3 to 20 times higher antioxidant activity than the other herbs studied.”
   
• Additionally, oregano has 42 times more antioxidant activity than apples, 30 times more than potatoes, 12 times more than oranges and 4 times more than blueberries. This is an amazing discovery when considering the health benefits derived from consuming herbs like oregano.  So what does this all mean for the general public? Antioxidants have become a synonym for good health in recent years. This is because antioxidants are a class of components that fight off the charged molecules known as free radicals, which cause chemical damage in the human body.  Free radicals are atoms or groups of atoms that cause damage to cells, which can lead to an impaired immune system and infections. Free radicals are also associated with degenerative diseases such as heart disease and cancer. Our bodies produce free radicals as part of the everyday metabolic breakdown of foods we eat.
   
• Excess free radicals are generated by exposure to radiation, rancid oils (fried foods), food additives (food coloring, sugars), chemicals (pesticides, nitrates added to cured meats) heavy metal pollutants, exposure to UV rays from the sun and smoking. According to researchers at the USDA, the destruction of free radicals “may help fight the occurrence of heart disease and stroke.”
   
• What does the Physicians’ Desk Reference for Herbal Medicines, 1st edition, say about oregano? Indications and Usage: The herb is used for respiratory disorders and complaints such as coughs and bronchial catarrh, and as an expectorant. In folk medicine it is used for dyspepsia, painful menstruation, rheumatoid arthritis, scrofula, urinary tract disorders, and as a diaphoretic. Precautions and Adverse Reactions: No health hazards or side effects are known in conjunction with the proper administration of designated therapeutic dosages.
   
• Are there any concerns about taking oregano and prescription medications at the same time? If you are taking a blood thinner such as Cumadin™, it is recommended that you exercise caution, simply because oregano has a naturally occurring blood-thinning property which could be substituted for the traditional recommendation of an aspirin a day.  According to the Natural Medicines Comprehensive Database, compiled by the editors of Pharmacist’s Letter and Prescriber’s Letter and available online at www.naturaldatabase.com, oregano is “likely safe” and has “Generally Recognized as Safe (GRAS) status in the US.” Possible Interactions with Drugs: The Natural Medicines Comprehensive Database states that “no interactions are known to occur, and there is no known reason to expect a clinically significant interaction with oregano.”
   
• Possible Interactions with Lab Tests: The Natural Medicines Comprehensive Database states that “no interactions are known to occur, and there is no known reason to expect a clinically significant interaction with oregano.”  In 1977, at the second International Congress of Phytotherapy and Aromatherapy in Monaco, a French doctor named Belaiche unveiled his Oregano Index that uses Oregano oil as the base reference to compare the bactericidal action of other substances. The reason he chose Oregano Oil is because he determined by rigorous laboratory experimentation that, out of all natural essential oils, Oregano was the closest to an ideal antibacterial agent.
   
• He used the analytical technique of Schroeder and Messing, who measured the halo” of bacterial inhibition in millimeters caused by specific essential oils in a bacterial culture medium maintained in petri dishes. He tested both the ability of essential oils to inhibit bacterial growth as well as to kill bacteria.

• Belaiche also chose to use bacterial cultures taken from sick persons rather than cultures grown in laboratories. He tested essential oils on test groups of bacteria that ranged from 20 to 90 different types such as E Coli, Candida, Staph, etc. Based on these experiments, Belaiche and other French doctors developed an  Aromatogramme” or a chart measuring the halo of inhibition caused by individual essential oils on specific bacterial cultures. After exhaustive studies he concluded the following statements: “This aromatic essence (Oregano) is almost always the leader. Among the most active oils Oregano is the “best of the best…” The essential oil of Oregano has always provided me with amazing results in treating infectious diseases.
   
• Besides Oregano oil’s bactericidal action, it also prevents spasms, convulsions and nervous disorders. In my estimation, the antispasmodic qualities help to synergize its wonderful antiseptic powers which comfort me every time I prescribe it for my patients. It is surprising that Oregano oil has been known for a long time but is only now being recognized for its therapeutic powers.”
   
• Belaiche and his colleagues devised a standard to determine which oregano oil would consistently provide therapeutic results. First they determined there were two constituents of Oregano oil, namely Carvacrol and Thymol (technically referred to as phenols}, which proved to be remarkable antibacterial agents. They analyzed Oregano oils from Spain, Morrocco, Italy, and Albania. They observed variations of 22.4% total of Carvacrol and Thymol in Albanian Oregano oil to 66.5% in Spanish Oregano oil.
   
• After careful study they decided to identify maximal therapeutic Oregano oil as containing a phenol total above 50% with a minimum of 40 % Carvacrol and the rest Thymol. During their tests in the 1970s they chose to work with the Spanish Oregano in the Labiatae family of plants, specifically called Floribundum Mumby, or generally classified as Origanum Vulgare.  The results of their studies indicate that therapeutic Oregano oil is distinguished by its high percentage of Carvacrol in comparison to Thyme plants which have much more Thymol than Carvacrol. Sometimes different species of Thyme plants are also called Oregano, but they are not as active as real Oregano oil, nor as safe to use for human internal consumption.
   
• Impressive results have been published about Oregano oil’s qualities. Back in 1918, a French scientist named Cavel did research on meat stock cultured in septic tank water. He found that Thyme oil and Oregano oil in very small doses were able to destroy and prevent the development of microbes.  In 1992, two researchers at the University of Bologna, Italy (Caccioni and Guizzardi) studied the fungicidal effects of essential oils on harvested fruits and vegetables. They determined that carvacrol derived from Oregano oil was able to almost completely inhibit spore development in fruits and vegetables at very minimal doses.
   
• Oil from the common herb oregano may be an effective treatment against dangerous and sometimes drug-resistant bacteria, a Georgetown researcher has found. Two studies have shown that oregano oil–and, in particular, carvacrol, one of oregano’s chemical components–appear to reduce infection as effectively as traditional antibiotics. These findings were presented at the American College of Nutrition’s annual meeting October 6 and 7 in Orlando, Fla.
   
• Harry G. Preuss, MD, MACN, CNS, professor of physiology and biophysics, and his research team, tested oregano oil on staphylococcus bacteria–which is responsible for a variety of severe infections and is becoming increasingly resistant to many antibiotics.  They combined oregano oil with the bacteria in a test tube, and compared oregano oil’s effects to those of standard antibiotics streptomycin, penicillin and vacnomycin. The oregano oil at relatively low doses was found to inhibit the growth of staphylococcus bacteria in the test tubes as effectively as the standard antibiotics did.  Another aspect of the study examined the efficacy of oregano oil and carvacrol, which is believed to be the major antibacterial component of oregano, in 18 mice infected with the staph bacteria Six of the mice received oregano oil for 30 days, and 50% of this group survived the 30-day treatment. Six received the carvacrol in olive oil, not oregano oil, and none survived longer than 21 days.
   
• Six mice received olive oil alone with no active agents (the control group) and all died within three days. A repeat study corroborated these findings, which demonstrates that there are components of oregano oil other than carvacrol that have antibiotic properties.  “While this investigation was performed only in test tubes and on a small number of mice, the preliminary results are promising and warrant further study,” Preuss said. “The ability of oils from various spices to kill infectious organisms has been recognized since antiquity. Natural oils may turn out to be valuable adjuvants or even replacements for many anti-germicidals under a variety of conditions.”  This study was sponsored by Waukegan, Ill.-based North American Herb and Spice. Georgetown University Medical Center includes the nationally ranked School of Medicine, School of Nursing and Health Studies, and a biomedical research enterprise.

References

1. Oil of Oregano
2. Oregano Products FAQ: 1. What types of research have been conducted using Oregano P73? – (Note: Only general research done on Oregano and Oregano Oil are listed above. Research done on Oregano P73 was excluded.)