Too much tea can cause rare bone disease
A woman from Detroit, Michigan developed a rare bone disease after drinking a pitcher of tea with at least 100 tea bags each day for 17 years, according to a study published Thursday in the New England Journal of Medicine.
After suffering pain in her arms, legs, hips and lower back for five years, the 47-year-old woman went to see a doctor who originally suspected cancer. The doctor therefore referred her to Dr. Sudhaker D. Rao, a physician at Henry Ford Hospital who specializes in endocrinology and bone and mineral metabolism.
Dr. Rao, who was one of the researchers of the study, said X-rays of the Michigan woman revealed areas of very dense bone on the spinal vertebrae and calcifications of ligaments in her arm. Accordingly, he and the other researchers suspected the woman had skeletal fluorosis – a bone disease caused by consuming too much flouride, which is a mineral found in tea and drinking water.
Indeed, researchers reported that the woman’s blood levels of fluoride were four times higher than what would be considered normal.
Like cancer, skeletal flourosis can show up on an X-ray as areas of dense bone, said Dr. Rao, who has seen cases of skeletal fluorosis in his native India.
"I was able to recognize it immediately," he said.
Although skeletal fluorosis is rare in the U.S., it is pervasive in other areas of the world where there are naturally high levels of fluoride in drinking water, including portions of India and China. While low amounts of fluoride are added to drinking water in the U.S. for the prevention of cavities, the amounts are not high enough to cause skeletal fluorosis.
According to Rao, excess fluoride is typically eliminated from the body by the kidneys, but if one consumes a lot of it – like the Michigan woman did with her tea drinking – over time, the fluoride forms crystal deposits on bone.
Meanwhile, the Michigan woman is not the only American to develop skeletal flourosis from drinking a lot of tea. A few other cases have been reported in the U.S. – and in each one, the patient typically drank a gallon of tea a day, said Rao, prompting him and his colleagues to instruct such patients to stop drinking tea, after which they experienced an improvement in symptoms since fluoride deposits gradually go away as the bone repairs itself.
SOURCE: New England Journal of Medicine
(N Engl J Med 2013; 368:1140 I March 21, 2013 I DOI: 10.1056/NEJMicm1200995)