24 Jul 2013

Cheap tea could brew up future health issues

How drinking too much cheap tea could brew up future health issues
Wednesday, July 24, 2013
By Zena Hawley

DRINKING some cheaper supermarket tea blends could be bad for people's health, according to a research study at the University of Derby.

There are worries that the tea blends contain enough fluoride to put people drinking at least four cups a day over their daily recommended levels, increasing the risk of skeletal and dental illnesses.
Levels of fluoride found in 38 tea products were compared with each other and to the US National Academy of Sciences' daily dietary reference intake of 4 milligrams a day, in the research by Laura Chan, Professor Aradhana Mehra and Professor Paul Lynch.
Significant differences in fluoride levels were discovered when economy black tea blends from the main supermarkets Asda, Tesco, Morrisons and Sainsbury's were compared with branded black and green tea blends and pure blends.
Economy black tea blends had the highest concentration of fluoride – an average of 6 milligrams per litre – over the recommended daily intake. Green tea blends had the next highest concentrations, followed by branded black blends with an average of 3.3 milligrams per litre and then pure blends with 0.7 milligrams.

Associate lecturer Laura Chan, who carried out the study for her PhD, said: "The tea plant, camellia sinensis, is a fluoride accumulator, with mature leaves storing most of the fluoride.
"When tea is harvested, these older leaves may be used to produce lower quality, stronger teas such as economy teas, whereas the bud and newer top leaves are used in the manufacture of higher grade and speciality teas.
"Although fluoride is considered an essential micro-nutrient for human health, in the prevention of tooth decay and promotion of healthy bone growth, excess fluoride in the diet can have detrimental effects.
"Dental fluorosis, the mottling of tooth enamel, and skeletal fluorosis, pain and damage to bones and joints through calcification, have occurred in the UK and America.
"All tea products should be considered as a main source of fluoride in the diet and we urge supermarkets and manufacturers of tea to consider stating fluoride concentration as part of the nutritional information found on food packaging."

The study is published in journal Food Research International.

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