Cranberry juice, already well-known as a remedy for urinary tract infections, may help protect against common infections caused by gastrointestinal viruses, reports Dominique Patton.
Adding a commercially available cranberry juice to intestinal viruses in the lab appeared to inactivate their ability to cause infection, US researchers told a microbiology conference yesterday.
Intestinal virus infections account for significant illness and billions of dollars in medical expenses each year. In developing nations especially, hundreds of thousands of infant deaths occur annually due to intestinal virus infections.
The researchers from St Francis College in Brooklyn, New York decided to investigate cranberry juice's power to fight these infections after looking at the growing number of studies showing its benefit against urinary tract infections in women.
The team tested the effects of the juice on intestinal monkey rotavirus SA-11 (SA-11) and other goat intestinal reoviruses.
Treatment of SA-11 with cranberry juice prevented the virus from attaching to red blood cells or infecting its host cells, the researchers reported at the American Society for Microbiology meeting in Atlanta.
Using high magnification microscopy to look at the SA-11 host cell cultures treated with juice, the researchers saw no viral particles.
"Our studies suggest a cranberry juice-induced antiviral effect upon selected intestinal animal viral disease-producing agents," said Patrice Cohen, a researcher on the study.
Human trials are needed before cranberry juice consumption can be recommended to help reduce viral intestinal disease, he added.
It is thought that the juice might destroy or modify receptor sites on the host cells to which viruses usually bind. Alternatively, it might damage the protein docking mechanism of the virus itself.
Researcher Dr Steven Lipson told the BBC News website: "Cranberry juice seems to have an effect on the replication cycle of the virus at an early stage so that it fails to penetrate the host cell."
He said that flavonoids and tannins in the juice, both of which have previously been shown to have an anti-bacterial effect, may be responsible for this benefit.
The study was partly funded by the Cranberry Institute and the Wisconsin Cranberry Board.