Drinking lemonade could help prevent painful
kidney stones, new research shows.
of the refreshing drink -- or even lemon juice
mixed with water -- may increase the production
of urinary citrate, a chemical in the urine
that prevents the formation of crystals that
may build up into kidney stones.
So conclude two studies presented Tuesday
at the American Urological Association annual
meeting in Atlanta.
Kidney stones develop when minerals from
urine crystallize and build up on the inside
of the kidney. In most people, urine contains
a chemical that prevents crystal buildup,
but that chemical does not work in people
prone to kidney stones. When the body tries
to remove the crystallized deposits through
the narrow tubes of the urinary tract, a person
may feel pain and burning.
In the study led by Kristina Penniston, an
assistant scientist in the Department of Surgery
at the University of Wisconsin School of Medicine
and Public Health, researchers retrospectively
examined the medical records of 100 patients
who had been prescribed lemonade therapy after
seeking treatment for calcium oxalate kidney
stones. Calcium oxalate stones are the most
common type of kidney stones.
"We'd been recommending lemonade therapy
for about 10 years, but within the last five
or six years, we really noticed that people
on lemonade therapy have extremely high urinary
citrate concentrations," Penniston said.
"We knew people were seeing results in
urine biochemistries, and [lemonade therapy]
was fairly well-tolerated."
About two thirds of the patients drank about
4 ounces of pure lemon juice that they poured
into 2.5 liters of beverages throughout the
day or 32 ounces of low-sugar or low-calorie
prepared lemonade, Penniston said. The remaining
patients in the study were treated with a
combination of lemonade therapy and potassium
citrate, a medication that maintains the antacid
level in urine.
After an average treatment time of about
40 months, "in both groups, urinary citrate
increased and so did urine volume. But the
increase in volume was only significant in
groups with lemonade therapy," Penniston
said. For patients prone to kidney stones,
drinking lots of fluids and increasing urinary
volume may help prevent future stone formation.
In another study presented at the conference,
conducted by researchers at Duke University,
12 patients with mild-to-moderate hypocitrauria
-- a condition that causes a person to produce
low levels of urinary citrate -- drank 120
milliliters of lemon juice mixed with two
liters of water throughout the day.
After the researchers compared the people
treated with lemonade therapy to patients
taking potassium citrate, results showed that
11 of the 12 patients had increased urinary
citrate levels during lemonade therapy.
The kidney stones of the people taking lemonade
therapy also decreased in size and number
during the course of the treatment, which
lasted an average of 41 months.
Although the results of these two studies
indicate that lemonade therapy may offer a
simple alternative treatment to people with
kidney stones who can't tolerate taking potassium
citrate, much more research needs to be conducted,
both study authors concluded.
"Both of these studies are addressing
a very specific individual -- individuals
with low urinary citrate. They're not suggesting
that everyone with a stone problem try this,"
said Dr. Eric N. Taylor, of Brigham and Women's
Hospital and Harvard Medical School, both
Taylor also noted that the type of lemonade
used in therapy may easily add extra sugar
or calories to a person's diet. "The
problem is, if someone would just drink 2
liters of lemonade, it could represent a significant
amount of calories and sugar," he said.
"When people think lemonade, they don't
necessarily think of lemon juice. The key
is you need real fruit," he said.