Cranberry Juice: Does it work to prevent UTI’s?

Not to suggest that there’s any connection between philosophy and cystitis, which apparently can plague older women.  However, the effectiveness of cranberry juice is one of the true old wives tales.  In short,  it does work:

The research, by Terri Camesano, associate professor of chemical engineering at WPI, and graduate students Yatao Liu and Paola Pinzon-Arango, and funded, in part, by the National Science Foundation, shows that a group of tannins (called proanthocyanidins) found primarily in cranberries affect E. coli in three devastating ways, all of which prevent the bacteria from adhering to cells in the body, a necessary first step in all infections:

  ● They change the shape of the bacteria from rods to spheres.    

  ● They alter their cell membranes.

  ● They make it difficult for bacteria to make contact with cells, or from latching on to them should they get close enough.

For most of these effects, the impact on bacteria was stronger the higher the concentration of either cranberry juice or the tannins, suggesting that whole cranberry products and juice that has not been highly diluted may have the greatest health effects.

The old wives thought the juice changed the ph of one’s body, which isn’t right.  Rather, it works right on the bacteria.  Now,  one needs to know,  a glass works for 6-24 hours.

This news was presented at the American Chemical Soc. meeting in 2006, but its appearance in Chemical and Engineering News, March 29, 2010, alerted my resident scientist, who passed the information on.

5 thoughts on “Cranberry Juice: Does it work to prevent UTI’s?

  1. I used to get UTI’s frequently. One physician told me to take extra vitamin C, with the reasoning that it would increase the acidity of my urine and therefore kill the bacteria. Nope.

    I did some research, found some older studies, and started drinking cranberry juice. Word of advice, get real cranberry juice, not the kind mixed with apple juice (that would be anything marked cranberry juice cocktail). I drink about a 1/2 cup of real cranberry juice per day, diluted with water to 12 oz. otherwise it is very strong and amazingly tart! I haven’t had a UTI in two years, and am pregnant right now (which can increase UTI frequency)!

  2. Meghan, thanks for the advice about amount, which is hard to get. Do you put any sugar in it? Or honey?

  3. I’m not sure the old wives thought it changed the Ph – I think that was an early theory about why it worked. You’re advised by some not to put sugar or honey in it, because bacteria like to eat both of those things. As do yeasts, and a yeast imbalance in the bladder is one hypothesised reason why certain women constantly get UTIs.

  4. “essence of cranberry” can also be obtained in capsule form – easier to carry around. “Don’t leave home without it”

  5. J, many thanks! I was trying to get the stuff down as liquid; that’s hard unless it’s sweetened, at leas for me.

    Monkey, I suspect I was joking about the Ph, but since they’re wise, who knows what they might have grasp without the technical vocabularly.

    I suspect the stuff about yeast and sugar isn’t entirely relevant if you take the cranberry, at least according to the research. The idea is that it immobilizes the bacteria. I’m also afraid that the “don’t eat sugar” would apply all the time, and not just when one is having the cranberry. That would be hard.

    Still, I wouldn’t believe anything I’m saying without checking it out more extensively, to be frank. Writing Dr C abut might be good.

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