Cranberries have for a number of years been a known therapy for urinary tract infections. Doctors are now discovering that the benefit from cranberries may even extend to protecting against viruses, according to results of study from New York-based researchers.
A non-specific antiviral effect has been shown from Cranberries, directed towards unrelated viral species by a commercially available cranberry fruit juice drink (the product they used was Ocean Spray brand, but of course these results would apply to any manufacturer). The researchers published their work in the journal Phytomedicine, one of the top scientific publications in the world of botanical medicines.
Researchers from St. Francis College, Mt. Sinai School of Medicine, and New York University report that commercially available cranberry juice neutralized these viruses: bacteriophages T2 and T4 and the simian rotavirus SA-11. The popularity of cranberries has been increasing due to a growing body of scientific evidence revealing the fruit's health benefits. There has been significantly growing consumer awareness and interest in the product. It doesn't hurt, of course, that cranberries taste great, are easy to access, and relatively inexpensive. Almost one third of parents in the US are now giving it to their children, many of them because of the effect upon childhood urinary tract infections.
France became the first country to approve a health claim for the North American cranberry species Vaccinium macrocarpon, which states that it can 'help reduce the adhesion of certain E.coli bacteria to the urinary tract walls'. Perhaps there can be further health claims down the road based on ongoing research about anti-viral activity.
In this study, the researchers exposed the viruses to cranberry, orange, or grapefruit juices and measured the virus infectivity. Cranberry juice was found to protect against both bacteriophage T2 and bacteriophage T4. For the latter phage (T4) the anti-viral activities were found to be rapid, dose-dependent, and unaffected by temperature, occurring at four or 23 degrees Celsius.
When the researchers turned their attention to the mammalian enteric virus, simian rotavirus SA-11, they found that a 20 per cent suspension of cranberry juice was enough to stop the virus from binding to the surface of cells, but a more dilute suspension (12 per cent) was not effective. This is a very significant finding.
On the other hand, the orange and grapefruit juices reduced the viral infectivity of T2 and T4 to 25 to 35 per cent of the control, respectively, stated the researchers.
Further studies are of course needed to elucidate the mechanisms of these findings and, of equal importance, to proceed to animal model systems.