Apr 23, 2015 9:00 AM

Author: Office of Public Affairs

Drinking tea is good for your health. It may lower the risk of cancer, it can encourage weight loss, and recent studies have shown tea can help lower blood pressure.

But one Arkansas man discovered there can be too much of a good thing.

In May 2014, a 56-year-old man arrived at Central Arkansas Veterans Healthcare System, complaining of weakness, fatigue and body aches. Doctors discovered that his kidneys were failing. He was placed on dialysis. After questioning the patient, they learned that he drank 16 8-ounce glasses of iced tea daily, which is about 1 gallon.

“Iced tea is full of oxalic acid, which, when taken in excess, deposits in your kidneys and mucks up the work of removing waste from the blood,” says Scott Youngquist, MD, an emergency physician at University of Utah Health. “This patient was drinking 16 8-ounce glasses of iced tea per day for an unknown period of time. This created a load of oxalic acid that his kidneys couldn't handle, leading to renal failure.”

Black tea is rich in oxalate, a compound found naturally in many foods. Too much of it can also lead to kidney stones. The man likely consumed 1,500 milligrams of the compound daily. As a comparison, the average person ingests between 150 and 500 milligrams of oxalate each day.

“This kind of kidney failure has also been reported due to excessive consumption of star fruit, cucumber fruit, rhubarb and peanuts,” Youngquist says.

Like tea, these foods are known for their health benefits. But as Youngquist says, “Anything consumed to excess can be toxic—including water!”