Why Dose Matters

pills_2348412bLast week, media outlets were quick to pick up the story of a research study[1] that showed cranberry extract isn’t as effective as antibiotics for the prevention of recurrent urinary tract infections (UTIs). The headlines were consistent: “Antibiotics beat cranberries,”[2] “Don’t bet on cranberry,”[3] and “Cranberries little help”[4].  Unfortunately, what is lacking from many of the medical news reports is a critical review of the study’s methodology and thus the validity and applicability of its results.  While a study comparing the efficacy of antibiotics and cranberry is a great idea, the cranberry extract studied contained the daily equivalent of merely 9.1 mg of proanthocyanidins, the key chemical constituent responsible for protecting against adherence of bacteria in the urinary tract.   This dose falls far short of the 72 mg daily dose of proanthocyanidins currently accepted as the most effective based on recent clinical studies[5], a problem admitted by the study’s authors in discussing their results.

Even at such a low dose, cranberry showed great promise.

After 12 months of taking either trimethoprim-sulfamethoxazole (TMP-SMX, 480 mg once daily) or cranberry capsules (500 mg, containing 4.55 mg of proanthocyanidins, twice daily):

  • the mean number of women experiencing at least 1 UTI was greater in the cranberry than the antibiotic group (4.0 vs 1.8; p=0.02)
  • the proportion with at least 1 UTI was also greater in the cranberry group (78.2% vs 71.1%; p=0.03)
  • median time to first UTI was 4 months in the cranberry group, vs. 8 months in the antibiotic group
  • 86.3% of fecal and 90.5% of asymptomatic bacteriuria E coli isolates were TMP-SMX resistant vs. 23.7% and 28.1% in the cranberry group
  • increased resistance rates for was other types of antibiotics were also found in the TMP-SMX group after 1 month
  • antibiotic resistance did not increase in the cranberry group

As noted by Galen’s Watch, “As part of a total treatment that included other supplements that have shown benefit in preventing UTI’s such as probiotics and vitamin C the outcome could be quite different. A typical treatment plan could include dietary recommendations and herbs, among other things.”[6]  All is not lost for cranberry.  At the correct dose, it remains an important part of a holistic approach to preventing UTIs.

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  1. Beerepoot MAJ et al. Cranberries vs antibiotics to prevent urinary tract infections. A randomized double-blind noninferiority trial in premenopausal women. Arch Intern Med [serial on the internet]. 2011 [cited 2011 July 30];171(14):1270-1278. Available from: http://archinte.ama-assn.org/cgi/content/short/171/14/1270.
  2. Freeman DW. For urinary tract infection, antibiotics beat cranberries. CBS News [website]. 2011 July 26 [cited 2011 July 30]. Avail­able from: http://www.cbsnews.com/8301-504763_162-20083454-10391704.html.
  3. Gardner A. Don’t bet on cranberry against UTIs. CNN [website]. 2011 July 25 [cited 2011 July 30]. Avail­able from: http://www.cnn.com/2011/HEALTH/07/25/antibiotics.cranberry.upi.prevention/.
  4. Walsh N. Cranberries little help for bladder. MedPageToday [website]. 2011 July 25 [cited 2011 July 30]. Available from: http://www.medpagetoday.com/InfectiousDisease/GeneralInfectiousDisease/27725.
  5. Howell AB et al. Dosage effect on uropathogenic Escherichia coli anti-adhesion activity in urine following consumption of cranberry powder standardized for proanthocyanidin content: a multicentric randomized double blind study. BMC Infect Dis [serial on the internet]. 2010 [cited 2011 July 30];10:94. Available from: http://www.biomedcentral.com/1471-2334/10/94#B12.
  6. Way S. Antibiotics beat Cranberries for UTI’s? Not so fast… Galen’s Watch

    Welcome Jess, student intern

    Please help me welcome Jess, a naturopathic student intern in her 4th year of studies, who will be joining me in my practice on Tuesdays from May until August this year. During the fourth year of naturopathic college, senior clinic interns work under the direct supervision of regulated naturopathic doctors to provide primary health care. Most of this time is spent working in the Robert Schad Naturopathic Clinic, the teaching facility of the Canadian College of Naturopathic Medicine (CCNM) and its satellite clinics. Students may also apply to intern with naturopathic doctors outside of CCNM. […]

    By | April 5th, 2012|Uncategorized|0 Comments

    Tolle Causam

    Tolle causam. Treat the cause. This directive seems so simple and obvious at first glance. Like any good detective, it implores us to search through the patient’s story, signs, and symptoms to seek out the root of ill health. Tolle causam urges us to uncover the source of disease, remove any obstacles to cure, and let the vis medicatrix naturae work its beautiful magic to restore health. If only it were so easy. Mercifully for both doctor and patient, sometimes it is. Tolle causam is sometimes translated as “identify and treat the cause.” (1) Other definitions allow for more plurality: “Identify and treat the causes.” (2, 3) A direct translation says something a little different. […]

    By | April 3rd, 2012|Philosophy|0 Comments

    Vegetable Soup

    Earlier this week while shopping at Fiesta Farms, my kids declared themselves chefs and started gathering vegetables for their version of “Red Pepper Soup.” Nevermind that they have always disliked all bell peppers, which I have long suspected is actually a food intolerance to Solanaceae, or nightshade, family vegetables (peppers, tomato, potato, eggplant). Regardless, they began dumping a variety of vegetables in the cart and teaching me how to make their recipe. I confess I made a few adjustments. I wasn’t convinced that sardines were a good idea, although I reserve the right to be wrong. Maybe they would have made the soup extra delicious. Anyways, I present to you my version of K & E’s recipe. (Sorry, I forgot to take a picture. Dinner at our house is often both busy and delicious. Instead, I offer you the cover of the book that likely inspired it all: Growing Vegetable Soup by Lois Ehlert) […]

    By | March 9th, 2012|Kids, Recipes|0 Comments

    The Healing Power of Nature

    A couple of weeks ago, I presented at the Ontario Forestry Association’s Annual Conference. This year’s theme was “Prescription for Nature: Healthy Forests for Healthy People”. It was an inspiring conference, with great speakers from the Back to Nature Network, Tree Canada, and the Kinark Outdoor Centre amongst others. I was asked to speak from a clinical perspective about the relationship between forests and human health, a topic I am very passionate about, as it speaks to the vis medicatrix naturae, or the healing power of nature. It was also a pleasure to present to a different audience than the usual naturopathic students I lecture to on a weekly basis. […]

    By | February 23rd, 2012|Health Research, Kids, Nature & Culture|0 Comments

    Constitutional Hydrotherapy

    The restorative powers of hydrotherapy may not be well known outside the spa environment in our time, but the use of hydrotherapy is well documented throughout history in Egyptian, Roman, Chinese, Japanese, and many other cultures. Hippocrates, an ancient Greek physician, prescribed bathing in spring water as a medical treatment. These traditions have continued and can be found in the practice of bathing in hot springs and cold water baths around the world today. Constitutional hydrotherapy, a technique developed by Dr. O.G. Carroll, is particularly effective at stimulating the immune system, achieving total body detoxification, and stimulating the body’s own innate capacity to heal itself. The word “constitutional” refers to the whole-body effects of this treatment. Although useful in almost any condition, it has been found specifically well suited for the treatment of digestive concerns, respiratory diseases, female reproductive problems, immune system balancing, circulatory conditions, neurological conditions, and environmental toxicity. […]

    By | February 1st, 2012|Hydrotherapy|0 Comments

    Warming Socks

    Runny nose? Sore throat? Chills? Fever? Sneezing? Congestion? Headache? Any or all of the above? Use the warming socks treatment. Warming socks works by stimulating the body’s natural healing responses during acute infections. In hydrotherapy terms, the technique is a kind of “warming compress”, which encourages the body to increase overall blood circulation in order to warm up the cold socks. In doing so, it draws preferentially from areas of congestion in the upper respiratory passages, head, and throat. It is also effective for pain relief. A safe treatment for the whole family, including the youngest of kids, warming socks is perfect at bedtime, or nap time, as it has a soothing and sedating effect, helping you to sleep through the night even when you’re feeling less than par. […]

    By | December 13th, 2011|Home Treatments, Hydrotherapy, Kids|0 Comments
    . 2011 July 26 [cited 2011 July 30]. Available from: http://camwatcher.typepad.com/cam_watcher/2011/07/antibiotics-beat-cranberries-for-utis-that-is-what-the-headlines-say-but.html.
By | July 30th, 2011|Health Research|2 Comments
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