On a hot summer day, a glass of sweet tea is a satisfying thirst quencher. But before pouring yourself a tall glass, here’s a thought to let steep: Too much sweet tea can cause dehydration and contribute to the formation of kidney stones.
“Kidney stones have a strong connection to your hydration status,” said Holly Mlodzinski, a registered and licensed dietitian at Hilton Head Hospital. “Sweet tea is definitely a high oxalate-content drink.”
Oxalate is a natural chemical commonly found in various teas and other foods such as spinach, okra, peanuts and rhubarb. Mlodzinski said the body can typically flush it out. But when consumed in excess, oxalate builds up in the urinary tract, forming hard, crystallized masses that are painful when they pass.
“Basically, it’s a buildup of minerals in your urine,” she said. “Most people can pass that mineral buildup.”
In places like Hilton Head Island and elsewhere in the South, where sweet tea is a part of everyday life, oxalate buildup can quickly become a problem.
De. Richard Vanderslice, a board certified urologist at Urology Group of Hilton Head, said that’s not uncommon.
“I’ve had patients who tell me they drink two to three large glasses of sweet tea at lunch,” he said.
Sweet tea alone may not lead to kidney stones, he said, but when coupled with other factors, such as diet and health, drinking too much sweet tea could make people more susceptible to developing them. Vanderslice recommends patients cut back to one glass of sweet tea a day. He also evaluates his patients for other risk factors, such as high blood pressure, obesity, diabetes and whether they have a history of kidney stones.
According to the National Kidney Foundation, more than half a million people per year are treated for kidney stones in the emergency room. The foundation also estimates that one in 10 people will be affected during their lifetime.
Areas in the Southeast and Southwest United States comprise what urologists refer to as the “kidney stone belt,” partially because people tend to get more dehydrated in warmer climates. Vanderslice said local urologists have reported an increase in kidney stones as the weather turns warmer.
“Summer is a more common time for kidney stones,” he said. “A major problem is people tend to drink less water than they think they do.”
Drinking lots of fluids such as sweet tea or other caffeinated beverages may seem like a flavorful and healthier way to stay hydrated, but they have the reverse effect.
“Caffeine has a natural diuretic effect, so it takes more fluids out of your body so you get dehydrated,” Mlodzinski said. “The main thing you should do is drink as much water as you can.”
To prevent kidney stones Vanderslice suggests drinking 2.5 to 3 liters of water per day alongside a healthy lifestyle.
“The best prevention is: One, good hydration; two, maintain a normal body weight; and, three, avoid excess salt intake,” he said.