Oil pressed from oregano leaves that contain the active ingredient carvacrol may be an effective treatment against sometimes drug-resistant bacterial infection. Georgetown University researchers have found that oil of oregano appears to reduce infection “as effectively as traditional antibiotics.”

Oil of oregano at relatively low doses was found to be efficacious against Staphylococcus bacteria and was comparable in its germ-killing properties to antibiotic drugs such as streptomycin, pencillin and vancomycin. [Science Daily 10/11/2001] The findings were presented by Harry G. Preuss, MD, professor of physicology and biophysics, Georgetown University, at the American College of Nutrition’a annual meeting in Orlando, Florida. The oregano oil was obtained from North American Herb and Spice Company, a Waukeegan, Illinois company that sponsored the study and markets their non-prescription products in retail stores un the trade names Oregamax and Oregacyn.

Earlier this year researchers at the Department of Food Science at the University of Tennessee reported that, among various plant oils, oil of oregano exhibited the greatest antibacterial action against common pathogenic germs such as Staph, E. coli and Listeria. [Journal Food Protection, Volume 64, July 2001] Last year British researchers reported oregano oil had antibacterial activity against 25 different bacteria. [Journal Applied Microbiology, Volume 88, February 2000] A clinical study in Italy has shown that oil of oregano can be used to treat intestinal parasites. [Phytotherapy Research, Volume 14, May 2000]

The body of positive evidence for oregano oil as a major antibiotic is growing. Among 52 plant oils tested, oregano was considered to have “pharmacologic” action against common bugs such as Candida albicans (yeast), E. coli, Salmonella enterica and Pseudomonas aeruginosa. [Journal Applied Microbiology, volume 86, June 1999] Pseudomonas is a type of germ that is getting more difficult to treat as it has developed strains that are resistant against antibiotic drugs.

Of recent interest are reports showing that carvacrol from oil of oregano kills spores, such as Bacillus cereus and Bacillus anthracis (anthrax). [Archives Microbiology, Volume 174, October 2000; Quarterly Review Biology, Volume 73, March 1998] Bacillus cereus is considered to be from the same species as Bacillus anthracis (anthrax). [Applied Environmental Microbiology, Volume 66, June 2000] In tests of antibiotics and antiseptics, Bacillus cereus is often used in studies in lieu of the anthrax strain. [University of Michigan News & Information Service, Sept. 23, 1998]

Oil of oregano is not to be confused with common oregano in the kitchen spice cupboard, which is usually marjoram (Origanum majorana or O. vulgare) rather than true oregano (Origanum vulgare).

The growing problem of antibiotic resistance has health authorities concerned. Already various germs are showing resistance to vancomycin, particularly to intestinal bacteria (Enterococcal species) among hospitalized patients. [Southern Medical Journal, Volume 94, August 2001] Vancomycin is considered to be the most potent antibiotic available and is withheld from use as a drug of last resort. Vancomycin costs about $16 per pill versus about $1 for the purest-strength oregano oil. Drug resistance does not develop against naturally-occuring antibiotics such as garlic and oil of oregano.

October 13, 2001