It’s official: Cranberries help cure urinary tract infections

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By Dr. James Stapleton

If you’ve had a urinary tract infection, you’ve probably heard all about the home remedy: cranberry juice.

For years, it was nothing but an “old wives’ tale” without any scientific proof.

Now, cranberry juice is widely accepted to fight the bacteria that causes UTIs…but the mechanism of exactly how it works is still not known.

A study from the Worcester Polytechnic Institute is finally shedding some light on the secrets of Cranberry juice’s bacteria fighting power.

According to researchers, 95 percent of UTIs are a pathogenic strain of the same E. Coli bacteria found in the intestines.  The “bad” E. Coli have little arm-like appendages that grab onto and anchor themselves to the cells of the urinary tract.

These tiny anchors are important because without them, every time you went to the bathroom, the force of your urine would simply flush the bacteria out of your body.

As soon as the E. Coli get a good grip on the Urinary Tract cell walls – they start multiplying. 


Fast moving little guys!

What’s amazing is E. Coli doubles in number in one hour and it only takes a few hours to cause an infection.

Cranberries have been known to help as far back as 1620.  Clinical trials were conducted in 1923 and researchers believed cranberries increased the acidity of urine, killing the bacteria.

Sixty years later, scientists realized cranberries did not make urine acidic enough to kill E. Coli.  

Now, a new study theorizes cranberries work to protect you from UTIs in a very different way.  Here’s the new theory: Cranberries contain large amounts of a chemical called proanthocyanidin or PAC. PAC functions almost like a shield that blocks the arms or anchors of E. Coli from attaching to the cells in the urinary tract.

These shields actually make the “anchors” crumble when they try to attach themselves to the urinary tract.

An ounce of prevention is worth…a pound f cranberries.

Here is something very important:  According to the research, Cranberries’ “shields” were only effective at preventing a UTI.  In other words, cranberry “shields” only

worked when E. Coli was trying to attach itself – once it was attached, cranberries did not have the same affect.  According to the researchers, "Cranberry juice seems more effective at preventing future bacterial infections than treating an existing one."

The study was published online on June 21 in the journal, Molecular Nutrition & Food Research.