The following is some information on Cranberries and their chemical makeup and usefulness. I thought it might be interesting info for sometime in the future. It is interesting and helpful to those that suffer from chronic bladder infections. Here is some info with references that I hope will help.
"The action of cranberry juice is due to acidifying the urine and the antibacterial effects of a cranberry component, hippuric acid. In addition, recent studies have shown components in cranberry juice to reduce the ability of bacteria to adhere to the lining of the bladder and urethra." ----American Council on Collaborative Medicine "The earliest investigations into the mode of action of cranberry juice focused on the effects on the acidity of the urine, and increased concentration of hippuric acid in the urine. However, it was found that the increase in acidity was small and transient and so would not impact upon the activity of the uropathogens.
In addition, although Hippuric acid is known to possess bacteriostatic properties, the levels detected in the urine were insufficient to achieve such bacteriostasis. More recent studies have shown that cranberry juice and cranberry juice enriched with fructose can inhibit the adherence of urinary tract isolates of E.coli to human uroepithilial cells.
The next step has been to try to identify the constituents
of cranberry juice which contribute to the anti adherence activity.
It has been found that the juice contains at least two adherence
inhibitors: one low molecular weight. The low MW compound specifically
inhibited the activity of the type 1 fimbriae. The low MW compound has
been identified and constitutes the fructose component of the juice
where it is believed to interfere with the mannose specific lectin
on the E.coli wall binding to the reception site on the epithelial
cell surface. Fructose had no inhibitory action on E.coli which had
Type P fimbrial. However, the high MW compound found in cranberry
juice was found to profoundly inhibit Type P fimbriae Fructose enriched
cranberry juice therefore has the potential to inhibit the attachment of
both types of E.coli fimbriae which are most commonly associated
with UTI."
---BioMed Newsletter 1991, Vol 2, Issue 6
"A germ
called E. Coli is a normal inhabitant of the colon. In some people,
it can climb from the surrounding skin up into the bladder by sticking
to the cells that line the urinary tract. Cranberry and blueberry
juices contain a chemical that prevents E. Coli from sticking to
urinary tract cells so they can't climb up into the bladder."
---JAMA
(Report #6149 3/15/94)
"The study shows cranberry juice reduces pre-existing
bacteria and the occurrence of new bacteria in the urinary tract.
It didn't test whether drinking cranberry juice prevents infections.
Contrary to a popular belief, cranberry juice doesn't reduce bacteria
by making urine more acidic. Researchers believe cranberry juice
inhibits bacteria from "sticking" to the bladder wall where they
can multiply and cause infection."
---Mayo Clinic Health Letter, June 1994
"For years, doctors have routinely advised patients to drink cranberry
juice to prevent urinary infections. In fact, it is cited as
an effective remedy for this problem in the U.S. Pharmacopeia, the
official listing of drugs in the United States. At one time, scientists
believed that cranberry acidified the urine, and in the process,
killed invading bacteria that could cause infection. Recently, however,
Dr. Anthony Sabota, a scientist at Youngstown State University in
Ohio, offered another possible explanation. His studies suggest that
cranberry prevents bacteria from sticking to the wall of the bladder,
thus flushing the potential troublemakers out of the body before
they can do their damage."
--- Earl Mindell, "Herb Bible"
The information I've seen indicate that cranberries contain a yet-unknown factor that prevents bacterial adhesion to urinary tract walls. No toxins that I know of. I believe cranberries contain benzoic acid. I have trouble with the probably synthetic benzoic acid used as a preservative (probably created by mold fermentation), I have no such problem with cranberries.