- Superfoods are extremely popular because of supposed health benefits.
- Surprisingly high fluorine content determined in some superfoods (16.4–373?µg/g).
- Significant contribution to adequate intake of fluorine in non-fluoridated areas.
- Upper limit for fluorine in fluoridated areas can be reached
- Wise consumption is advised because of possible adverse effects of fluorine
Recent years have seen soaring interest in exotic superfoods, which are believed to have extraordinary health benefits. The purpose of the study was to broaden the current knowledge on exotic superfoods and to analyse them for fluorine1 since excessive intake during prolonged periods of time can cause adverse effects. The fluorine content was determined in 18 plant-based exotic superfoods available on Slovenian market by fluoride ion selective electrode after prior total decomposition with alkaline carbonate fusion. In 8 of the analysed samples, the F content was surprisingly high in comparison to F content in commonly consumed foods (< 3 µg/g). The highest F content was found in matcha [Fine powder green tea] (373 µg/g), followed by gotu kola (111 µg/g) and gingko biloba (91.0 µg/g). The F content in tulsi, neem, brahmi, gynostemma and moringa was lower and ranged between 16.4–68.8 µg/g. Despite high F content, these superfoods do not pose a risk to human health in non-fluoridated water areas, because they are usually consumed in low quantities. However, in fluoridated water areas (e.g. some parts of Ireland, United Kingdom, United States, Canada) or in areas with high natural fluoride concentration in drinking water, superfoods should be consumed with caution, since the intake of F can with simultaneous consumption of superfoods and tea on a normal diet easily exceed the adequate intake or even reach the upper limit for fluorine. The F content in these 8 superfoods was also surprisingly high in comparison to the usual F content in most plant species (< 10 µg/g). The high F content in matcha is understandable since it is made of Camellia sinensis L. leaves, but the high F content in other superfoods is worrisome because the reason for such high F content is unknown and it is possible that these superfoods are contaminated with fluoride due to industrial or agricultural activities.
*See original abstract online at https://www.sciencedirect.com/science/article/abs/pii/S0022113920300725