"The data suggest, for the first time, a non-specific antiviral effect towards unrelated viral species by a commercially available cranberry fruit juice drink," wrote the researchers in the journal Phytomedicine .
Researchers from St. Francis College, Mt. Sinai School of Medicine, and New York University report that commercially available cranberry juice (Ocean Spray) neutralised the viruses: bacteriophages T2 and T4 and the simian rotavirus SA-11.
The popularity of cranberries has been increasing in recent years as a combination of strong marketing campaigns and a body of scientific evidence revealing the fruit's health benefits have contributed to growing consumer awareness and interest in the product.
The fruit has long been considered an effective method of fighting urinary tract infections, something that has led to almost one third of parents in the US giving it to their children, according to a recent study.
In 2004 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'.
According to the new study, the anti-bacterial benefits may be matched by anti-viral benefits.
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, with no virus infectivity measurable.
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.
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 needed to elucidate the mechanism(s) of our findings and, of equal importance, proceed to animal model systems," concluded the researchers.
The study was funded by the Cranberry Institute (Massachussetts) and by a St. Francis College Faculty Research Award.
Source: Phytomedicine Volume 14, Issue 1, Pages 23-30 "Antiviral effects on bacteriophages and rotavirus by cranberry juice" Authors: S.M. Lipson, L. Sethi, P. Cohen, R.E. Gordon, I.P. Tan, A. Burdowski and G. Stotzky