Cranberry (Vaccinium macrocarpon Ait.) has been utilized traditionally for prevention of urinary tract infections (UTI), and clinical research supports this claim.  An important mechanism of action may be the bacterial anti-adhesion activity attributed to ingesting cranberry products.  Proanthocyanidins (PACs) in cranberry have been shown to inhibit primarily P-fimbriated E. coli adhesion to uroepithelial cells in vitro and ex vivo, interfering with this primary step in the infection process.  PACs, also referred to as condensed tannins, are oligomers and polymers of monomeric flavan-3-ols, such as catechin and epicatechin.  The PACs in cranberry contain a high proportion of the unusual double A-type linkages, which may be important structural features in the anti-adhesion process. In one study, other food sources of PACs that contain only B-type linkages (chocolate, grape, apple and green tea) were consumed.  However, they did not elicit ex vivo bacterial anti-adhesion activity in urine following ingestion. Daily consumption of 36mg of cranberry PACs has shown effectiveness in inhibiting bacteria from adhering to bladder cells, multiplying and consequently causing infection. This amount of PACs can be easily consumed in a 9-10 oz (266-296 ml) serving of 27% cranberry juice cocktail. But inconsistencies in methods currently used commercially to measure levels can result in the over- or under-estimation of potency levels, leaving product manufacturers and consumers without good data. Recently, Brunswick Labs (BL) developed a new, commercially viable method of measuring PACs-the BL-DMAC method. To validate this method, 11 samples of cranberry products were obtained (five from U.S. sources and six from European sources) for PAC quantitation analysis. Powdered samples were coded and sent blind to five different analytical laboratories (three in the U.S., one in China and one in Europe) for analysis by the BL-DMAC method. Each laboratory reported statistically consistent results of PAC levels.

"It is important to have an accurate, standard method for cranberry PAC quantitation that can be performed quickly and inexpensively in any commercial lab," said Boxin Ou, Ph.D., inventor of the BL-DMAC method. "In our study, we have shown that the BL-DMAC method is validated for this use. It utilizes a commercially available standard, which is vital to obtaining accurate results among different laboratories."

"Universal adoption of this standard worldwide by the cranberry industry will allow producers to use one standard method to ensure accurate labeling of PAC levels in products, and aid consumers in selecting products with sufficient PAC levels to obtain bacterial anti-adhesion activity," added James Nichols, President of Brunswick Labs.

The BL-DMAC method is published in the Journal of the Science of Food and Agriculture (April 21, 2010). Contact info@brunswicklabs.com for more details