Urologist warns iced tea can contribute to painful kidney stones

August 3, 2012

(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."

Explore further: Kidney stone mystery solved

Related Stories

Kidney stone mystery solved

April 18, 2012
Kidney stones strike an estimated 1 million Americans each year, and those who have experienced the excruciating pain say it is among the worst known to man (or woman).

Recommended for you

Zika virus stifles pregnant women's weakened immune system to harm baby, study finds

August 21, 2017
The Zika virus, linked to congenital birth defects and miscarriages, suppresses a pregnant woman's immune system, enabling the virus to spread and increasing the chances an unborn baby will be harmed, a Keck School of Medicine ...

Fatty liver can cause damage to other organs via crosstalk

August 21, 2017
Nonalcoholic fatty liver disease is increasingly common. Approximately every third adult in industrialized countries has a morbidly fatty liver. This not only increases the risk of chronic liver diseases such as liver cirrhosis ...

Novel approach to track HIV infection

August 18, 2017
Northwestern Medicine scientists have developed a novel method of tracking HIV infection, allowing the behavior of individual virions—infectious particles—to be connected to infectivity.

Faulty gene linked to obesity in adults

August 18, 2017
Groundbreaking new research linking obesity and metabolic dysfunction to a problem in the energy generators in cells has been published by researchers from the Harry Perkins Institute of Medical Research and The University ...

Two lung diseases killed 3.6 million in 2015: study

August 17, 2017
The two most common chronic lung diseases claimed 3.6 million lives worldwide in 2015, according to a tally published Thursday in The Lancet Respiratory Medicine.

New test differentiates between Lyme disease, similar illness

August 16, 2017
Lyme disease is the most commonly reported vector-borne illness in the United States. But it can be confused with similar conditions, including Southern Tick-Associated Rash Illness. A team of researchers led by Colorado ...

0 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.