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Enhancing Cranberry with Phenolic Antioxidants for UTI Benefits |
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by Dhiraj Vattem, Dr. Reza Ghaedian and Kalidas Shetty
Enhancing Cranberry with Phenolic Antioxidants for UTI Benefits
Urinary tract infections (UTI) are a
significant health problem affecting
millions of people globally each year.
They are second in incidence only to the viral
and bacterial infections of the upper respiratory
tract. Women are especially prone to UTI.
About one quarter of the women will have the
infection at sometime in their lives and the
incidence increases with age. UTI in men are
not so common but they can be very serious
when they do occur.
Disease pathogenesis
The average adult passes about a quart and a
half of urine each day. The amount of urine
varies, depending on the fluids and foods a
person consumes. Normal urine is sterile and
contains fluids, salts and waste products from
cellular metabolism but it is free of microorganisms
such as virus, bacteria and fungi.
The urinary tract above the urethra is normally
bacteriologically sterile. Infection arises
when the urethral meatus and surrounding
perineum are colonized with a mixture of skin
and bowel flora such as Escherichia coli (E.
coli), which are normally present in the colon.
This colonization of bacterium in the urethra
is often the starting point of UTI and is called
urethritis. Once colonized the bacterium progressively
migrate upwards to the bladder and
the upper urinary tracts. This often happens
with age and recurrence occurs if the infection
is not treated promptly. This results in the
infection of the bladder (cystitis) and then of
the ureters of the kidneys to cause
pyelonephritis.
Other microorganisms called Chlamydia
and Mycoplasma may also cause UTI in both
men and women. These infections however,
tend to remain limited to the urethra and
reproductive system and may be sexually
transmitted. Any abnormalities of the urinary
tract that obstruct the flow of urine, such as a
kidney stone or an enlarged prostate gland,
raise the risk of infection. Conditions such as
pregnancy, prostatic hypertrophy, urethral
strictures and neurological malfunctions
which cause incomplete emptying of the
bladder also increase the chances of infection.
Patients or elderly people treated in nursing
homes also have a high risk of infection from
the catheters, or tubes, placed in the bladders
which have been shown to be a common
source of contamination.
Recent research has shown that people
with diabetes have a higher risk of a UTI
because of changes in the immune system.
Any disorder that suppresses the immune
system raises the risk of a urinary infection.
Infants with abnormalities of the urinary tract
have been shown to contract UTI. Higher incidence
of UTI in women is perhaps because of
the shorter length of a woman’s urethra which
allows the bacteria to quickly migrate to the
bladder. Also, a woman’s urethral opening is
near sources of bacteria in the perirectal area,
which increases the chances of contamination.
Symptoms
The common symptoms include frequency and
urgency of urination (dysuria), suprapubic discomfort,
cloudy and pale pink or blood-stained
urine, slight or absent fever. The urinary system
is structured in a way that helps ward off infection.
Urine usually has a low pH, high concentration
of salts and urea which inhibit or kill the
microorganism. The regular urine flow through
the ureters and bladder normally prevent urine
from backing up toward the kidneys. Urine also
dilutes the pathogens and expels them. In men
the prostate gland produces secretions that slow
bacterial growth. In both sexes, immune
defenses also prevent infection. The epithelial
cells of the bladder are coated with mucus,
which prevents bacteria from adhering to the
bladder wall.
Treatment approaches
In spite of the body’s defense mechanisms,
infections still occur. This is because of the
relative acid stability of the strain of E. coli
that causes UTI and the inability of the host to
launch a strong immune response toward the
infection. Cranberry (Vaccinium macrocarpon)
has been historically used not only as
a food, but also as medicine. It was introduced
to European settlers by the Penobscot
Tribe of Maine, who used cranberries to treat
kidney stones and other urinary problems.
Cranberries were also used to clear the
blood, and as treatment for stomach ailments,
liver problems, gall bladder disease, vomiting,
appetite loss and scurvy. Cranberry was a popular
treatment for UTI prior to the introduction
of antibiotics, although it was only
recently that its effectiveness was scientifically
demonstrated. Cranberry juice has also been
shown to improve the health of the urinary
tract by lowering the urinary pH and acting as
a flushing agent. Another mode of action is
through prevention of bacterial binding to
the urinary tract by phenolic metabolites in
cranberry.
Phenolic Antioxidant Enrichment
Historical consumption of cranberry and its
juice and its recent scientific recognition has
provided significant improvements in the
control of UTI, however, recurrences are still
common and are a major problem in handling
this disease.
One of the major scientific breakthroughs
is going to be in the treatment of this disease
by controlling the disease both at the
pathogen level and also by triggering the host
antioxidant and potentially immune
response. One strategy to achieve this could
be by improving the antioxidant properties of
cranberry juices.
 All plants have phenolic biochemicals
which are synthesized by the plant as a
defense mechanism for its protection against
environmental and pathogen attack. These
phenolic phytochemicals have been shown to
have antimicrobial and antioxidant properties.
Cranberry also has several phenolic biochemicals
such as proanthocyanidins,
tannins and specifically catechins, however, it
is not rich in phenolics that are responsible
for high antioxidant (free radical scavenging)
activity. Enrichment of phenolic antioxidants
in cranberry juice would provide an
efficient synergistic strategy for treatment of
UTI along with cranberry’s known benefits.
The phenolic antioxidants such as ellagic
acid, released by fermentation of cranberry or
rosmarinic acid derived from the enrichment
of the juice by the addition of herbs or herbal
extracts, will have multi-fold benefits. The
properties of these phytochemicals, such as
Origanox-containing high rosmarinic acid,
can potentially provide additional barrier to
the survival of the pathogenic bacteria as well
as cause a positive modulation of the antioxidant
pathways in the body which may positively
influence the immune system. This
positive modulation of the host immune
system could support the body’s defense
response against the pathogen to not only
inhibit or kill the bacteria in its initial stages
of infection but could also help in prevention
of future recurrences. TH
Dhiraj Vattem is a doctoral student and
Kalidas Shetty is associate professor of Food
Science both are at the University of
Massachusetts—Amherst, MA.
Dr. Reza Ghaedian is R&D director of
Decas Cranberry Products, Wareham, MA.
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