Cranberry juice has long been association with urinary tract health, and earlier studies have established that this is due to its anti-adhesion mechanism.
James Greenberg, MD, a gynaecologist at Brigham and Women's Hospital in Boston, USA, wanted to establish whether the same effect also applies to sweetened dried cranberries.
His team conducted a small pilot study involving five women with culture-confirmed urinary tract infection. Their urine was tested after consumption of Ocean Spray's Craisins, and after consumption of raisons.
The researchers found that the women demonstrated an increase in anti-adherence activity of as much as 50 percent after the Craisins.
"It is the unique structure of the PAC's found in the North American cranberry that is responsible for keeping certain E. coli bacteria from causing infection by adhering to the urinary tract. This pilot study suggests that not just cranberry juice, but other forms of the fruit may be helpful in fighting infection."
Although the study was only small, Ocean Spray is taking heart at its findings and believes it could help stir up more interest in the fruit, particularly from bakery, dairy and cereal product manufacturers.
In April 2004 France became the first country to permit products containing cranberries to carry a health claim on their labels.
This initial claim, which said that consumption of certain amounts of the North American cranberry species vaccinium macrocarpon can 'help reduce the adhesion of certain E. coli bacteria to the urinary tract walls', was relevant to products using the fruit concentrate or extract in powder form, often used in supplements, as it required daily consumption of 36mg.
In December of that year this was extended to permit the claim for regular consumption of juice drinks or cordials, or 300ml daily of a minimum 27 per cent cranberry juice drink.
Recurrent cystitis affects 2 million women annually in France and prompts around 5 million calls to doctors. The number of doctors' appointments is 2.5 times more than in the US, making the health claim a valuable asset for cranberry product makers looking to expand in this market.
UK supermarket Sainsbury's reported recently that sales of cranberry products increased by 67 percent last year over 2004 - a leap thought to have been helped by publicity surrounding a study into alternative therapies commissioned by the Prince of Wales.