CRANBERRY SIDE EFFECTS AND BENEFITS
cranberry juice and urinary tract infection, cranberry juice benefits, cranberry pills
Cranberry [Vaccinium macrocarpon] is found in North America. Its common names are
cranberry, American cranberry bog cranberry. Cranberries are the fruit of a native plant
of North America. These red berries are used in many food products, beverages and in
herbal products in form of extracts, teas, and capsules or tablets. [NCCAM]
Cranberry may benefits various kidney conditions. Cranberry has been used to remove
toxins from blood and prevent kidney stones* and urinary tract infections.
[*please, read the section of cranberry side effects]
ACTIVE INGREDIENT IN CRANBERRY
Cranberry contains proanthocyanidins.
CRANBERRY BENEFITS - ON ATHEROSCLEROSIS Atherosclerosis is the deposition of
plaques containing cholesterol and lipids in arterial walls. Atherosclerosis always lead to
heart attacks and stroke. Consumption of food and beverages containing flavonoids may
decrease the risk of atherosclerosis. Some experiments have demonstrated that
flavonoids are antioxidants and inhibit LDL oxidation, platelet aggregation. Cranberries
contain both hydroxycinnamic acids and flavonoids, researchers thought that cranberries
may be able to decrease the risk of atherosclerosis. 
CRANBERRY BENEFITS - ON URINARY TRACT INFECTIONS Around 60% of women
experience at least one urinary tract infection (UTI) during their lifetime, of whom up to
20% will experience recurrence.  Some studies testing cranberry products including
pills for their benefit on prevention of urinary tract infections have shown promise.
[NCCAM] In vitro studies have shown that cranberry [proanthocyanidins] prevented E.
coli, the most common bacterial cause of urinary tract infections, from adhering to the
cells lining the wall of the bladder. This anti-adherence action may reduce the ability of
the bacteria to cause a urinary tract infection. [1-3]
Transmission electron microscopy imaging of bacteria grown in the presence of cranberry
materials reveals fewer flagella than in bacteria grown under control conditions.
Furthermore, swimming and swarming motility are also hindered when the bacteria are
grown in the presence of these cranberry compounds. [B2]
A few trials have also shown that cranberry reduced bacteria levels in the urinary
bladders in older women. [4.5] Cranberry has been shown to reduce of older women
significantly better than placebo, an action that may help to prevent urinary tract
infections. However, these studies have generally been small in size, and some were not
randomized or controlled. [NCCAM]
In a double-blind of 221 premenopausal women with recurrent urinary tract infections
were randomized to 12-month prophylaxis use of trimethoprim-sulfamethoxazole (TMP-
SMX), 480 mg once daily, or cranberry capsules, 500 mg twice daily. It was found that
TMP-SMX, 480 mg once daily, is more effective than cranberry capsules, 500 mg twice
daily, to prevent recurrent urinary tract infections, at the expense of emerging antibiotic
resistance. [My comment- their dosing frequency and dose are different. We can not say
(TMP-SMX or cranberry) can really offer a better benefits to the users.]
Cranberry-lingonberry juice is also found to be effective in preventing urinary tract
infections in our earlier randomized clinical trial. [B1]
DOSAGE - Cranberry Pills, Capsules
Most products suggest taking cranberry juice extracts, 400 mg, (in the form of capsules or
pills) twice a day.  But, you should follow doctor's instruction.
CRANBERRY SIDE EFFECTS
Eating cranberry products in food amounts appears to be safe. Under normal conditions,
cranberry extracts are also safe and well-tolerated that does not have significant drug
However,cranberry side effect can be serious, if it happens. It is known that cranberry
juice has a moderately high concentration of oxalate, a key ingredient for kidney stones.
Patients suffered from nephrolithiasis should consult doctors before taking cranberry
Also, Cranberry juice does provide calories and sugar; in excess amounts it may lead to
weight gain or tooth decay. Technically, weight gain can be a side effect of taking
cranberry juice. Further, drinking too much cranberry juice may also produce stomach
and intestinal disturbance such as diarrhea. 
1. Sobota AE. Inhibition of bacterial adherence by cranberry juice: Potential use for the treatment of
urinary tract infections. J Urol 1984;131:1013Â–6. 2. Zafriri D, Ofek I, Adar R, et al. Inhibitory activity of
cranberry juice on adherence of type 1 and type P fimbriated Escherichia coli to eucaryotic cells.
Antimicrob Agents Chemother 1989;33:92Â–8. 3. Howell AB, Vorsa N, Der Maderosian A. Inhibition of
the adherence of P-fimbriated Escherichia coli to uroepithelialÂ—all surfaces by proanthocyanidin
extracts from cranberries. New Engl J Med 1998;339:1005Â–6. 4. Avorn J, Monane M, Gurwitz JH, et al.
Reduction of bacteriuria and pyruria after ingestion of cranberry juice. JAMA 1994;271:751Â–4. 5. Walker
EB, Barney DP, Mickelsen JN, et al. Cranberry concentrate: UTI prophylaxis. J Family Pract 1997;45:
167Â–8 [letter]. 6. Brown DJ. Herbal Prescriptions for Better Health. Rocklin, CA: Prima Publishing,
1996, 57Â–61. 7. Terris MK, Issa MM, Tacker JR. Dietary supplementation with cranberry concentrate
tablets may increase the risk of nephrolithiasis. Urology 2001;57:26Â–9. 9. Cranberry Natural Remedy,
RealAge.com August 16, 2005. 10. Cranberry and urinary tract infection. Drug Ther Bull. 2005 Mar;43(3):
17-9. 11. Cranberry for prevention of urinary tract infections. Am Fam Physician. 2004 Dec 1;70(11):2175-
7. 12. Reed J. Cranberry flavonoids, atherosclerosis and cardiovascular health. Crit Rev Food Sci Nutr.
2002;42(3 Suppl):301-16 Cranberry [NCCAM] National Center for Complementary and Alternative
Medicine Online Publication December 2005 [B1] Tapiainen T, et al, Biofilm formation and
virulence of uropathogenic Escherichia coli in urine after consumption of cranberry-
lingonberry juice.Eur J Clin Microbiol Infect Dis. 2011 Aug 7 [B2] Hidalgo G, Cranberry
Materials Inhibit Escherichia coli CFT073 fliC Expression and Motility. Appl Environ
Microbiol. 2011 Aug 5.
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