BMJ  2003;327:E65 (4 October), doi:10.1136/bmjusa.01090003 (published 5 September 2002)

BMJ USA: Letter

RAPID RESPONSES FROM BMJ.COM

European, not American, cranberries

This article originally appeared in BMJ USA

Editor—I would like to point out an interpretational problem with the study by Kontiokari et al, caused by use of the word "cranberry." The study was planned to further substantiate the beneficial effects of juice from the American cranberry (Vaccinium macrocarpon) for prophylaxis of urinary tract infections. The American cranberry is indeed an old folk remedy in North America, and it has been shown that ingredients of that berry interfere with bacterial adhesion to mucosa. All of these data, which come from research with the American cranberry, are cited to explain the results of the study by Kontiokari et al. However, their study did not use juice from the American cranberry, but instead used a mixture of lingonberry juice and juice from the European cranberry (V oxycoccus). To my knowledge, few data are available on the ingredients of the European cranberry. Do they also contain a high amount of proanthocyanidins, which prevent bacterial adhesion? They may do so, as the species are closely related botanically. Nevertheless, it is important to make clear that juice from a closely related but different fruit has been applied in this study.

Private practice in Lindau/Germany rnowack{at}t-online.de

---

 

Another means besides proanthocyanidins

Editor—Zafriri et al showed that the fructose in cranberry juice was about one-tenth as selective for the mannose lectins on type 1 pili, but was still sufficient to block adherence of the bacteria to cellular mannose.¹

King and colleagues showed that mannose prevented adherence of Pseudomonas, Streptococcus xooepidemicus, and E coli to equine endometrial tissue.² They also observed a dose-dependent retrograde movement of spermatozoa in the presence of higher concentrations of mannose (personal communication).

Maybe the time will come that we can use simple sugars such as these to prevent post-coital urinary tract infections as well as unwanted pregnancies.

Hale Center, Texas, USA ahj_d_o{at}hotmail.com

References

1. Zafriri D, Ofek I, Adar R, Pocino M, Sharon N. Inhibitory activity of cranberry juice on adherence of type 1 and type P fimbriated Escherichia coli to eukartotic cells. Antimicrob Agents Chemother 1989;33:92-98 [Abstract/Free Full Text]
2. King SS, Young DA, Nequin LG, Carnevale EM. Use of specific sugars to inhibit bacterial adherence to equine endometrium in vitro. Am J Vet Res 2000;61:446-449 [CrossRef][ISI][Medline]

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?