Most teas contain safe amounts of fluoride, UF study finds

If you drink tea, you can rest assured about your children's teeth or your adult bones, now that a University of Florida research team has found that most teas contain safe amounts of fluoride.

Drinking tea can benefit human health, but it contains fluoride, and too much fluoride can lead to teeth discoloration and malformation for children and bone problems for adults, said Lena Ma, a UF/IFAS professor of soil and water sciences. If you drink too much of it, scientists are concerned you might get sick from dental fluorosis in children or skeletal fluorosis in adults. The situation can be aggravated if water used for brewing tea contains high amounts of fluoride.

"Few people may be aware of the high fluoride content in some teas," said Ma, who led a new study that researched fluoride levels in traditional and herbal teas.

Ma and her research team brewed 47 types of teas in a lab. Based on a formula for the average daily intake of tea, they found the teas fell within safe limits for both adults and children excluding a few examples, which are traditional teas from Asia, Ma said. Fluoride concentration in these teas borders on limits that could be dangerous, but only if consumed to excess, she said.

"Your chances for bone ailments increases if you ingest 6 milligrams of fluoride per day," Ma said. Her study showed the recommended highest daily fluoride consumption is 5.2 milligrams per day.

Ma cautions that people might still get too much fluoride by consuming water, other beverages and food, and her research did not consider fluoride from other sources. Those include drinking water and food, which would likely push the fluoride levels above the safe limit, she said.

Globally, people drink more tea than any other beverage, according to a 2014 report from the Food and Agriculture Organization of the United Nations. That may be in part because tea is rich in caffeine, polyphenols and antioxidants, which all benefit human health, Ma's study says.