饮茶要适度 过度饮茶可导致氟骨病

食品伙伴网导读：茶长久以来是一种公认的健康饮品，在中国乃具有悠久的饮用传统，目前也被全世界所接受，但是过度饮用仍然对身体有害。根据对四例晚期骨骼氟中毒患者的最新研究分析表明：他们所喝的茶中的氟化物是罪魁祸首。对茶发生怀疑的主要原因是这四个人都长期的饮用大量的茶叶，在过去10到30年内，他们每人每天大约饮用1到2加仑（3.8-7.6L）的茶叶。专家称，成年人每天饮用2-4杯茶是对健康有益的。食品伙伴网友情提醒您：好东西亦不可过量饮用。欲了解更多详情，请阅读下面的原文报道。

原文报道： By Guy Montague-Jones, 15-Jul-2010

Related topics: Regulation & Safety

New research conducted on four advanced skeletal fluorosis patients suggests that the fluoride in their tea could have been responsible for the condition.

Suspicion that tea may be to blame was raised by the fact that the common link between the patients was their very high tea consumption. Each person drank 1 to 2 gallons (3.8 to 7.6 litres) of tea daily over the past 10 to 30 years.

Previously studies had estimated that the fluoride content of black tea stood at between 1 and 5 milligrams per litre but Dr Gary Whitford and his colleagues at the Medical College of Georgia in the US decided to investigate further because of the anecdotal evidence of the common tea link between the skeletal fluorosis patients.

Their research, the findings of which were presented this week at the 2010 International Association of Dental Research Conference in Barcelona, indicate that there could be much more fluoride in tea than previously thought. Results of their investigation indicate that there could be as much as 9 milligrams of fluoride in a litre of tea.


Methodology

Most published studies on fluoride in tea use a method of measurement that does not account for the fluoride that combines with aluminum to form aluminum fluoride in tea. So instead, Whitford and his team used a diffusion method, which breaks the aluminum-fluoride bond so that all fluoride in the tea samples can be extracted and measured.

He tested seven brands of store-bought black tea, steeping each for five minutes in deionized water, which contains no fluoride. The amount of fluoride in each sample was 1.4 to 3.3 times higher using the diffusion method than the traditional method.

Implications

Commenting on the results, Whitford was careful to point out that the results should not be a cause of concern for moderate or even relatively heavy tea drinkers. Indeed, interest in tea has bloomed in recent years, as research reveals the positive health benefits of constituents like polyphenols.

He said: “The additional fluoride from drinking two to four cups of tea a day won’t harm anyone; it’s the very heavy tea drinkers who could get in trouble.”


“The bottom line is to enjoy your favorite tea, but like everything else, drink it in moderation.”