Iced tea may cause painful kidney stones



Drinking iced tea can contribute to painful kidney stones, a Loyola University Medical Center urologist has warned. 
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.
"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, Loyala University Chicago Stritch School of Medicine.

The most common cause of kidney stones is not drinking enough fluids. And during the summer, people can become dehydrated from sweating. Dehydration, combined with increased iced tea consumption, raises the risk of kidney stones, especially in people already at risk.
"People are told that in the summertime they should drink more fluids. 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 more harm,"
Milner said.
Though hot tea also contains oxalate it's hard to drink enough to cause kidney stones, Milner said.
Men are four times more likely to develop kidney stones than women, and the risk rises dramatically after age 40. Postmenopausal women 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 through urinary tract. But stones sometimes grow large enough to become lodged in the ureters causing problems.
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.