The fluoride content of select brewed and microwave-brewed black teas in the United States by Pamela Ruth Pehrsson , Kristine Y.Patterson, Charles R.Perry

Fluoride (F) in take is recognized to be important for dental health.Tea leaves are known Faccumulators and brewed tea as well as the water used for brewing may contribute significantly to individual intake. The USDA’s Nutrient Data Laboratory determined the F content of brewed and microwaved teasusing geographically matched tap water samples.Two brands of top-selling regular and one of decaffeinated tea bags were purchased in 36 locations and brewed either by steeping in boiled water or with microwave heating followed by steeping. The mean F content for caffeinated regular brewed tea was 373 49 mg/100 g(n = 63)and for decaffeinated tea was270 46 mg/100 g(n = 34).The overall mean for F in microwaved regular tea was lower than regular brew (364 40 mg/100 gvs.322 30 mg/100 g(n = 36)). In all cases, prepared tea using water from the Mid west had the highest F-values.The mean Fcontent of the brewed  teas was 3–4 times higher than the national mean of the tap water, analyzed separately (71 33 mg/ 100 g). These data are the first nationally representative F-values for brewed teas, and will provide valuable information to the dental and medical research communities in assessment of fluoride intake and impacton dental health.

Link : https://www.ars.usda.gov/SP2UserFiles/Place/80400525/Articles/JFCA_TeaFluoride.pdf