Last week, media outlets were quick to pick up the story of a research study 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,” “Don’t bet on cranberry,” and “Cranberries little help”. 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, 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.” All is not lost for cranberry. At the correct dose, it remains an important part of a holistic approach to preventing UTIs.
- 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.
- 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.
- 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/.
- 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.
- 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.
- Way S. Antibiotics beat Cranberries for UTI’s? Not so fast… Galen’s Watch . 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.
I started making granola at home after becoming disillusioned with the cost of healthy cereal options for my kids. I'm a savoury breakfast kind of person so I had never tried it before, but I knew I could make a granola that was gluten-free, high in fibre, and low in sugar. [...]
(or any another kind of disaster situation) Knowledge about how to use wild plants as food and medicine may not be common to the average city dweller, but with my quick guide, you too will be better suited to survive a zombie invasion or another post-disaster scenario. 1. Burdock root [...]
Fibroids, benign growths in the uterus, are one of the most common gynecological health issues. According to American statistics, approximately 40-60% of women have fibroids by age 35; by age 50, up to 80% of women will have had uterine fibroids at some point in their life. African-American women are significantly more [...]
Guest post by Sairupa Krishnamurti, student intern Ayurveda Primer Ayurveda is an ancient South Asian system of healing that dates back over thousands of years. From Sanskrit, ayu = life, and veda = wisdom. Ayurveda is often translated as the “knowledge of life, or science of life”. The medicine is vast, but throughout its nature-based teachings an emphasis is placed on self-awareness and self-care. Practices that one can do at home are often taught, such as breathing exercises, meditation, yoga and self-massage. […]
Many of us may think we talk openly about sex but far too often I have patients who come to see me for sexual health concerns they have never discussed with other healthcare providers. I am glad that my patients feel comfortable asking me about a wide variety of issues related to sex practices: how to avoid giving and getting sexually transmitted infections, how to get or not get pregnant, and how to improve sexual function. Dissatisfaction with one’s sex life, sometimes called sexual dysfunction, is a rather common concern.