WOLVERHAMPTON, England--In a study published in the January journal Applied and Environmental Microbiology (67, 1:475-80, 2001), researchers from St. George's University (West Indies) and the University of Wolverhampton found powder garlic extracts to work better than garlic oil against human enteric bacteria. Although all bacteria tested were susceptible to each garlic form, the powder was more active in fighting off bacteria. "Allicin, which is the active part of garlic, is pretty stable when it is a solid," said Julia Campbell, technical director at Fullerton, Calif.-based Stauber Performance Ingredients Inc. "The advantages of having the powder, as a manufacturer, is that it's easier to process, distribute and so forth." She also added that in garlic powder is easier to encapsulate than an oil.

The oil may also not be as potent as the powder. "Allicin is a really aggressive germicide, and some of the allicin would be destroyed by the heat process used to make the oil," Cass Ingram, D.O., author of Supermarket Remedies and Life-Saving Cures, a book that focuses on the health benefits of garlic. "If you took raw garlic, you'd derive the greatest benefits." He added that some consumers would prefer the oil because it may be easier to digest and absorb.

The study's authors concluded that garlic oil may be more therapeutic than the powder form, but more study needs to be conducted to investigate this further. For more information, visit aem.asm.org.