Cranberry (Vaccinium macrocarpon) has long been
cherished for its nutritional and medicinal properties.
The fruit is juicy and tart and contains a range of
valuable nutrients including vitamin C, flavonoids, flavonols and
phenolic compounds. The primary flavonoids in cranberry are
proanthocyanidins (also referred to as condensed tannins). Benzoic
acid is the major phenolic compound while the major flavonols are
quercetin and myricetin.
From a medicinal perspective, cranberry has evolved from a folk
remedy to a scientifically proven product that can provide protection
against urinary tract infections (UTI). While fighting UTIs is its most
popular use, recent research has found cranberry is also beneficial
for fighting gum disease, lowering cholesterol levels, preventing
ulcers and even fighting cancer.
Cranberry and Urinary Tract Health
UTI is the second most common infection that affects women. The
symptoms—urinary burning, frequency, urgency and pain—are
unpleasant and in some cases debilitating. About fifty percent of
all women will experience a UTI in their lifetime and many women
suffer recurrent UTIs. In the U.S. alone, about 8.3 million doctor
visits per year are attributed to UTIs and they are the second leading
cause of lost work days for women. Women are at greater risk of
UTI because their urethra is closer to the rectal area making it easier
for bacteria to get to the bladder. Pregnancy increases a woman’s
risk because the growing baby presses on the bladder, which may
prevent it from completely emptying. Menopause also increases
UTI risk because lower estrogen levels lead to thinning of the urinary
tract, making it easier for bacteria to enter. Sexual intercourse is the
most common cause of UTI in women age 20 to 40. During sex,
bacteria can be pushed from the rectal area toward the vagina and
can then enter the urethra and ascend into the bladder. Men can
also get UTIs. Those with an enlarged prostate, diabetes, or cancer
and those under stress are at increased risk.
The typical treatment of a UTI involves antibiotic
therapy, which is associated with various health and
societal risks. Side effects of antibiotics may include
nausea, diarrhea, stomach cramps, and yeast infections,
to name a few. Plus, the overuse of antibiotics is now recognized
as a major factor in the development of resistance—the bugs are
becoming stronger than the drugs, leaving people vulnerable for
attack by bacteria. Antibiotics are also expensive. Some of the broad-spectrum
drugs are $80 or more for a week supply. As with most health
problems, prevention is the key.
Cranberry has been revered for centuries for urinary tract health but
it wasn’t until the 1990s that its mechanism was elucidated. Cranberry
works in part by preventing bacteria from adhering to the bladder.
The condensed tannins or proanthocyanidins (PAC) adhere to the tiny
hairs of the bacterial surface, changing the structure of the bacteria
and preventing bacteria from implanting in the bladder wall. Scientists
have also discovered another mechanism by which cranberry works.
Researchers at Worcester Polytechnic Institute found that chemical
changes caused by cranberry juice create an energy barrier that keeps the
bacteria from getting close to the urinary tract lining in the first place.
Juice versus Supplements
Most of the early research on cranberry involved testing juice
cocktail with mixed results. This may have been due to the fact the
amount of juice used in the studies varied greatly. Those studies
finding positive results involved drinking large amounts of juice:
up to 34 ounces per day. Not only is that difficult for most people
to comply with, but most juices contain only 27 percent cranberry
juice, with added sugar and water. For those watching their weight
and trying to control blood sugar, all this excess sugar presents
a problem. Pure juice is available in health food stores but it is
quite expensive and very tart. For all of these reasons, cranberry
supplements offer significant advantages.
The most widely studied cranberry supplement on the market is
Cran-Max®, a full spectrum product that contains all the vital parts
of the cranberry—the fruit, seeds, skin and juice. A major drawback
with many cranberry juice powders is the bioactives are quickly
destroyed by stomach acid, and thus do not reach the desired site
of action. Cran-Max utilizes a patented Bio-Shield® technology
where the natural plant fibers form a lignan-cellulose matrix that
protects the cranberry from destruction by the stomach acids,
delivering the nutrients to the lower gastrointestinal tract where
they can be absorbed. Cran-Max contains standardized condensed
tannins and fiber, and is the only cranberry supplement that
contains the full phytonutrient value of the whole cranberry.
A study published in the Canadian Journal of Urology, compared the
effects of pure cranberry juice (250 ml three times daily), cranberry
tablets (Cran-Max 250 mg twice daily) and placebo in the prevention
of UTI in a group of 150 women with a history of recurrent UTIs.
Both the pure juice and cranberry tablets significantly reduced the
occurrence of UTI but the cranberry tablets proved to be the most
In another study conducted by researchers in France the effect
of a single post-coital (after intercourse) dose of Cran-Max was
evaluated in a group of 120 women with a history of recurrent UTI.
The study was conducted over 45 days and women were randomized
into one of the following treatments: GynDelta® (French brand of
Cran-Max), dry cranberry extract with 36 mg proanthocyanidins or
placebo. Women were instructed to take their treatment six hours
after intercourse. Over the study period, only 10.8 percent of the
women in the GynDelta group suffered from a UTI compared to
18.9 percent in the cranberry extract group and 43.2 in the placebo
group. Thus the researchers concluded that the Cran-Max product
was most effective in preventing post-coital UTI.
The most recent study on Cran-Max involved 137 women with
recurrent UTI. The women were randomized to receive either 500
mg of Cran-Max or 100 mg of trimethoprim (an antibiotic) for six
months. The researchers found that the time to first recurrence of
UTI was not significantly different between the groups. The lead
researcher concluded: “Our trial is the first to evaluate cranberry
(Cran-Max) in the prevention of recurrent UTIs specifically in older
women, and the first head-to-head double-blind comparison
of cranberry versus antibiotic prophylaxis. Trimethoprim had a
very limited advantage over cranberry extract (Cran-Max) in the
prevention of recurrent UTIs in older women and had more adverse
This landmark study adds to the growing body of evidence on
cranberry for bladder health. More people today are interested
in natural methods for prevention of UTI and are trying to avoid
antibiotic use due to concerns with side effects and resistance.
Guidelines for Use
Cranberry juice is generally well tolerated with no known adverse
effects. Those with diabetes or insulin resistance should limit their
intake of juice cocktail as it contains a significant amount of sugar.
Cranberry juice, consumed in amounts found in foods, is thought
to be safe in pregnancy and breastfeeding. There is no evidence
of harm to the mother or baby as a result of consuming cranberry.
Cranberry should be used cautiously in those taking anti-coagulants
such as warfarin because it may enhance the blood-thinning effect
of the drug.
The dosage of cranberry juice has varied in the research. The
most significant study on cranberry juice utilized a dosage of 250
ml of pure juice three times daily. The recommended dosage for
Cran-Max is 500 mg daily for prevention.
Several new studies are underway evaluating the therapeutic effects
of cranberry. The National Institutes of Health is funding research
on cranberry’s effects on treating urinary tract infections, heart
disease, yeast infections and gum disease. Other researchers are
investigating its potential against cancer, stroke and viral infections.
With mounting research published in mainstream medical journals
cranberry is now getting the attention it deserves.
Cranberry + Probiotics
Individuals with recurrent UTI should consider taking
a probiotic along with their cranberry supplement. Use
of antibiotics, whether for UTI or other reasons, causes
alterations in normal gastrointestinal and vaginal flora
and this often leads to diarrhea and yeast infections.
Probiotic supplements can help replenish normal
flora and also help inhibit the growth of pathogenic
bacteria, thus providing a supportive role for both the
treatment and prevention of UTI. Look for a probiotic
that is stable at room temperature, guaranteed potency
(bacteria count guaranteed through expiration), dairy
free, and made with human strains which allow for ideal
implantation in the intestine, such as Kyo-Dophilus®.
For individuals interested in maintaining and
supporting intestinal function and urinary health there
is Cran-Logic®. Cran-Logic contains the unique
combination of Cran-Max cranberry extract and Kyo-
Dophilus probiotics. These proprietary ingredients
have been clinically studied and found to be beneficial
for urinary tract, intestinal function, and many other
aspects of health.
Cran-Logic is made from 100 percent cranberry
fruit solids through a process that intensifies the natural
benefits of the whole cranberry, without the use of
any solvents, preservatives, sugars, water, flavorings or
Cran-Logic promotes a healthy urinary tract by
reducing the risk of bladder and yeast problems. Since
bad bacteria that cause urinary tract issues live in the
intestines, the cranberry extract in Cran-Logic prevents
the growth and adherence of these bad bacteria, while
the probiotics maintain healthy intestinal function.
Clinical studies have confirmed the value of cranberry
and probiotics for bladder and intestinal health.
Additionally, Cran-Logic replenishes your normal
intestinal micro-flora. The balance of flora can be upset
due to various therapies, poor diet, exposure to harmful
bacteria, travel to foreign countries and even stress.
Cran-Logic also offers a number of other benefits:
It can inhibit the harmful toxins that bad bacteria
produce; counter the adverse effects of therapies;
produce essential vitamins and enzymes that are vital
for health; and improve overall intestinal function.