The following information is not given as medical advice but is the shared experience of many thousands of satisfied Sweet Cures customers with whom we have had contact since 2003.
E.coli is considered to be an acid adaptive bacterium, capable of synthesising its nutritional requirements from the surrounding acids in its environment. Since cranberry creates acidic urine conditions (cranberry juice produces hippuric acid in the urine) when you drink cranberry juice or eat cranberry tablets, you are giving E.coli a suitable environment in which to multiply.
In fact, the whole reason for us putting up this page is because so many customers since 2003 have told us that taking cranberry makes their infections worse. So how did cranberry get its reputation?
There is an anti-adhesion effect from cranberry, but we believe that for the vast majority of bladder infection agents, the increased bacterial metabolic rate that results from the acidic urine that you get from drinking cranberry is likely to cancel out any anti-adhesion benefits from taking it.
On the other hand, it seems to be the case that for most gram negative bacteria, living in alkali conditions is like living in their own waste - not ideal conditions. In alkali urine they slow down their metabolic rate and it can take them twice as long to produce a cell division (to double). That's why taking potassium citrate, which clearly makes the urine more alkaline, eases the situation in most cases.
It is also known that if the E.coli in your body originated from cattle fed on a high grain diet, they can be 1000 times more resistant to acid than other E.coli. These bacteria thrive in acids. They are tough little bugs that adapt to utilise the environment they are exposed to. They can even get through stomach acids intact.
Acid resistant bacteria populate the human gut when you eat meat or food contaminated with the acid-loving strains, so the very first time you get an E.coli infection, the bacteria are likely to be already acid resistant.
The cycle: E.coli and Klebsiella (and some other gram negative uropathogens) have 'burst cycle' population explosions that occur under optimum feeding conditions. It goes like this - you drink cranberry or something else that makes the urine acidic - or get dehydrated and there is a build-up uric acid in the bladder. Within a short period of time when the acidic urine gets into your bladder, the E.coli in there burst into a frenzied multiplication cycle, doubling their colony size over the next 15 to 20 minutes.
For Escherichia coli, for example, the rate of growth and division of a single bacterium (also called the generation time) during the log phase is 15 to 20 minutes. In the log phase, most of the bacteria in a population are growing and dividing.
World of Microbiology and Immunology 2003
They use up the acids in your urine in the process, and pass alkalis and endotoxins. As the urine becomes more alkaline, and the bacteria are effectively living in their own waste, they gradually become semi-dormant, slowing down their multiplication rates by as much as 100%. You take another drink of cranberry or eat some more cranberry tablets, and the process begins again. It's not that they can't metabolise alkalis, but they don't seem to be so efficient at that.
It's a well-known fact that many people get bacterial cystitis when they are dehydrated and thus build up a high level of urea (uric acid) in the urine. There must be some bacteria present for any bacterial infection, but the cystitis happens because the bacteria have been given the acidic environment in which to multiply out of control. You get a feel for the hardiness of E.coli when you consider that urea is a powerful antiseptic. Customers repeatedly tell us,
I got de-hydrated,
I had a fair bit of alcohol,
I drank a lot of cranberry, or
I drank a lot of orange juice.
By avoiding cranberry, vitamin C in the form of ascorbic acid, alcohol, red meat and coffee, and making the urine more alkaline you take away the acids that are considered one of the bacteria's primary sources of nutrition, effectively starving their environment. You can also use a citrate salt like potassium citrate, magnesium citrate, calcium citrate or sodium citrate to make the urine more alkaline. You will quickly find out the truth or otherwise because for most bacteria the moment you alkalise the urine to approximately 7.5pH you experience relief.
But, as always, for medical advice always see your doctor.
Our customers have repeatedly told us that Cranberry usually provides temporary relief from an infection followed by a worsening of symptoms.
When you first take cranberry it kills off any bacteria that cannot survive the acidic environment. However, any bacteria that do not have a weakness for acid will survive and, when they multiply, will produce more bacteria that like the acidic environment. Even if you didn't already have acid-loving bacteria in the first place, because uropathogens like E. Coli, are very fast mutators, they are likely to produce mutations that can make better use of the acidic environment than the original cranberry survivors. This is the similar to the reproductive mechanism that produces antibiotic resistant bacteria.
Until reasonably recently it was believed that the acid in cranberry killed the uropathogens, but it is now more widely accepted that this is not the case. As explained, they adapt quickly to acidic conditions.
When you increase your d-mannose intake by taking D-Mannose , you get up to fifty times as much d-mannose with every level teaspoonful than you get in a half pint of cranberry, and you also get the advantage of not acidifying your urine (or your stomach for that matter). But if you try taking cranberry at the same time, you will stop the mannose from working. How do we know that? Well, almost everyone who has told us they've been taking cranberry at the same time as D-Mannose , hasn't been getting better. And as soon as they stopped the cranberry, they started getting better.
A University Of Edinburgh study in 2012, reached the same conclusions:
Prior to the current update it appeared there was some evidence that cranberry juice may decrease the number of symptomatic UTIs over a 12 month period, particularly for women with recurrent UTIs. The addition of 14 further studies suggests that cranberry juice is less effective than previously indicated. Although some of small studies demonstrated a small benefit for women with recurrent UTIs, there were no statistically significant differences when the results of a much larger study were included. Cranberry products were not significantly different to antibiotics for preventing UTIs in three small studies.
University Of Edinburgh
And the EFSA concluded:
The Panel concludes that the evidence provided is not sufficient to establish a cause and effect relationship between the consumption of XXXXX cranberry products and the reduction of the risk of UTI in women by inhibiting the adhesion of certain bacteria in the urinary tract.
Note: The above information is specifically referring to gram-negative bacteria like E.coli and Klebsiella, which are responsible for the vast majority of bladder infections. However, cranberry is thought to be useful when Proteus type bacteria are affecting the bladder.
If you are one of the few for whom D-Mannose doesn't help your problem, you need to have the bacteria that are affecting you properly checked at a lab.
If it is Proteus, also ask which type: the susceptibility of Proteus to particular antibiotics varies with type. Any treatment will involve a level of guesswork unless you have enough details about what is affecting you, so please seek help.
One lab that our customers recommend: www.medichecks.com
Potential problems that may arise with cranberry juice
 Studies of Urinary Acidity II. The Increased Acidity Produced by Eating Prunes and Cranberries.
Blatherwick, N.R. and Long, M.L., Journal of Biological Chemistry, 1923, 57: 815-818.
 Efficacy of Cranberry Juice and Asorbic Acid in Acidifying the Urine in Multiple Sclerosis Subjects.
Schultz, A, Journal of Community Health Nursing, 1984, 1 (3): 159-169
 Contrasting effects of potassium citrate and sodium citrate therapies on urinary chemistries and crystallization of stone-forming salts.
Kidney International 1983 Sep; 24(3): 348-52.
 Effect of Cattle Diet on Escherichia coli O157:H7 Acid Resistance.
Austin, P.R., Cloud, K.A., Hovde, C.J., Hunt, C.W. and Williams, C.J., Applied Environmental Microbiology, July 1999, 65 (7): 3233-3235
www.research.ed.ac.uk - Cranberries for preventing urinary tract infections
www.nhs.uk - Cranberry juice no good in preventing bladder infections
onlinelibrary.wiley.com - Cranberries for preventing urinary tract infections
www.efsa.europa.eu - Health claim related to Ocean Spray Cranberry
www.encyclopedia.com - (World of Microbiology and Immunology)
www.ncbi.nlm.nih.gov - Contrasting effects of potassium citrate and sodium citrate therapies on urinary chemistries and crystallization of stone-forming salts.
news.yale.edu - Myth: Cranberry as cure-all for UTIs.
Sweet Cures ’ Anna talks about her battle with cystitis. Read More