CHICAGO—Iced tea contains high concentrations of a chemical that leads to the formation of kidney stones, according to a urologist at Loyola University.
“For many people, iced tea is potentially one of the worst things they can drink,” said Dr. John Milner, assistant professor, Department of Urology, Loyola University Chicago Stritch School of Medicine, Maywood, Ill. “For people who have a tendency to form kidney stones, it’s definitely one of the worst things you can drink.”
Iced tea contains high concentrations of oxalate, one of the key chemicals that lead to the formation of kidney stones, which affects about 10 percent of the population in the United States. Hot tea also contains oxalate, but it isn’t as easy to consume a quantity large enough amount to encourage the formation of stones.
Men are four times more likely to develop kidney stones than women, and the risk rises dramatically once they reach their 40s. Postmenopausal women with low estrogen levels and women who have had their ovaries removed also have an increased risk of developing stones.
Kidney stones are small crystals that form from the 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. Most of the time kidney stones are so small that they are harmlessly expelled from the body. But on some occasions, the stones grow to the point that they can become lodged in the ureters.
The most common cause of kidney stones is the failure to drink enough fluids. During the summer, people are generally more dehydrated due to sweating. The dehydration combined with increased iced tea consumption raises the risk of kidney stones, especially in people who are prone to develop them.
“People are told that in the summertime they should drink more fluids,” said Milner. “A lot of people choose to drink more iced tea, thinking it’s a tastier alternative. However, in terms of kidney stones, they’re actually doing themselves a disservice.”
The popularity of iced tea has grown dramatically with more than 2 billon gallons consumed a year in the United States, according to the Tea Association of the U.S.A.
Much of iced tea’s appeal is due to the belief that it is healthier than other beverages such as soda and beer.
To quench thirst and to properly hydrate, there is no better alternative than water, Milner said. You might try flavoring it with lemon slices. Lemonade helps to ward off kidney stones.
“Lemons are very high in citrates, which inhibit the growth of kidney stones,” Milner said. “Lemonade, not the powdered variety that uses artificial flavoring, actually slows the development of kidney stones for those who are prone to the development of kidney stones.”
