Can Drinking black tea cause kidney problems?

New England Journal of Medicine said that Kidney failure occurred in a man who drank nearly a gallon of black tea that contains oxalate. Drinking or eating products containing oxalate including tea, nuts, wheat bran and chocolate can lead to kidney stones and of taken in excessive amounts like this man from Arkansas, kidney failure.

The New England Journal article, ‘A Case of Iced-Tea Nephropathy’ said:

Cases of acute oxalate nephropathy have been reported with Averrhoa carambola (star fruit), A. bilimbi (cucumber tree fruit), rhubarb, and peanuts. Our patient had none of the factors that have previously been associated with hyperoxaluria, such as gastric bypass surgery, overingestion of ascorbic acid, the use of “juicing,” or ethylene glycol poisoning. The average daily intake of oxalate in the United States is 152 to 511 mg per day,1,2 which is higher than that recommended by the Academy of Nutrition and Dietetics (<40 to 50 mg per day).

Black tea is a rich source of oxalate, containing 50 to 100 mg per 100 ml, a level that is similar to or higher than that in many foods considered to be rich in oxalate.3-5 About 84% of tea consumed in the United States is black tea. With 16 cups of tea daily, the patient’s daily consumption of oxalate was more than 1500 mg — a level that is higher than the average American intake by a factor of approximately 3 to 10.

We speculate that oxalate nephropathy may be an underrecognized cause of renal failure. In cases of unexplained renal failure in which proteinuria is absent and abundant oxalate crystals are present in urine sediment, a thorough dietary history should be obtained, because the kidney dysfunction could be a manifestation of oxalate nephropathy from an oxalate-rich diet.

The case presented here was almost certainly due to excessive consumption of iced tea.

The Associated Press had this to say:

The 56-year old man went to the hospital last May with symptoms like weakness, fatigue, nausea and body aches, the Associated Press reports. His doctors, writing in Thursday’s New England Journal of Medicine, said they had already ruled out several other possible causes when their patient said he drank 16 eight-ounce cups of iced black tea every day.