That afternoon spot of tea may be good for the soul, but it could be harmful to the body.
Researchers say the level of fluoride that occurs naturally in instant tea can cause bone pain in those who consume large amounts.
The study was conducted at the Washington University School of Medicine, as researchers looked for reasons why a middle-aged woman was suffering from severe pain in her spine.
But they note she drank one to two gallons of super-strength tea every day.
The researchers' findings were consistent with aching, dense bones reported among tea drinkers in China and Tibet.
Another researcher, who studied fluoride treatments to cure osteoporosis, says the latest research just goes to show that anything consumed in excess isn't good.