Urologist warns iced tea can contribute to painful kidney stones

(Medical Xpress) -- This is the peak season for drinking iced tea, but a Loyola University Medical Center urologist is warning the popular drink can contribute to painful kidney stones.

Iced tea contains high concentrations of oxalate, one of the key chemicals that lead to the formation of kidney stones, a common disorder of the urinary tract that affects about 10 percent of the population in the United States.

"For people who have a tendency to form the most common type of kidney stones, iced tea is one of the worst things to drink," said Dr. John Milner, assistant professor, Department of Urology, Loyola University Chicago Stritch School of Medicine.

The most common cause of kidney stones is not enough fluids. And during the summer, people can become dehydrated from sweating. Dehydration, combined with increased iced , raises the risk of kidney stones, especially in people already at risk.

"People are told that in the summertime they should drink more fluids," Milner said. "A lot of people choose to drink more iced tea because it is low in calories and tastes better than water. However, in terms of kidney stones, they might be doing themselves a disservice."

Though also contains oxalate, it's hard to drink enough to cause kidney stones, Milner said. About 85 percent of tea consumed in the United States is iced, according to the Tea Association of the USA.

Men are four times more likely to develop kidney stones than women, and the risk rises dramatically after age 40. with low estrogen levels and women who have had their ovaries removed also are at increased risk.

Kidney stones are small crystals that form from minerals and salt normally found in the urine in the kidneys or ureters, the small tubes that drain urine from the kidney to the bladder. Kidney stones usually are so small they are harmlessly expelled from the body. But stones sometimes grow large enough to become lodged in the ureters.

To quench thirst and properly hydrate, water is the best choice, Milner said. Real lemonade (not powdered) is another good option. "Lemons are high in citrates, which inhibit the growth of kidney stones," Milner said.

Milner advised that people at risk for kidney stones should cut back on foods that contain high concentrations of oxalates, such as spinach, chocolate, rhubarb and nuts. They should ease up on salt, eat meat sparingly, drink several glasses of water a day and eat foods that provide adequate amounts of calcium, which reduces the amount of the body absorbs.

Milner also advises that if you drink iced tea and have , ask your specialist if the drink could be a contributing factor. (Patients aren't always asked.) If so, it is relatively easy to check if you are producing too many oxalates.

"Like many people, I enjoy drinking iced tea in the summer," Milner said. "But don't overdo it. As with so many things involving a healthy lifestyle, moderation is the key."

add to favorites email to friend print save as pdf

Related Stories

Drinking green tea helps prevent kidney stones

Nov 13, 2009

(PhysOrg.com) -- Drinking green tea can help prevent the formation of large kidney stones, report Chinese scientists in the Royal Society of Chemistry journal CrystEngComm.

Of mice and men... and kidney stones

Mar 01, 2008

Kidney stones are very common – and painful – in men. About 3 in 20 men (1 in 20 women) in developed countries develop them at some stage. Mice, however, rarely suffer though the precise reasons are unknown. Jeffrey ...

How to ... avoid kidney stones

Jul 17, 2009

These solid masses that form in the kidneys can grow big enough to cause severe pain and even infection as they pass into the urinary tract.

Lemonade can help prevent kidney stones

Apr 22, 2010

(PhysOrg.com) -- We've all heard the expression, "when life gives you lemons, make lemonade." Passing a kidney stone would qualify for one of life's "lemons," but did you know that drinking lemonade has been shown to prevent ...

Recommended for you

Four die of bird flu in Libya: minister

14 hours ago

Four people have died of bird flu in Libya in recent days, the health minister of the country's internationally recognised government said on Saturday.

Ebola expert calls for European anti-virus 'corps'

Dec 26, 2014

Europe will be "vulnerable" if it does not regard viruses as a "national security issue" like the United States, the microbiologist who discovered Ebola said in an interview published Friday.

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.