Herbal medicines and cancer

For thousands of years the aristolochia馬兜鈴 plant with its reddish-yellow flowers has been a mainstay支柱 of Chinese herbal medicine草藥. Sometimes referred簡稱 to as birthwort馬兜鈴 in Europe, the toxic有毒 nature性質 of the plant was discovered in the 1990s when dozens of Belgian women began developing kidney failure腎衰竭 and urinary tract泌尿道 cancers. They had been using aristolochia-based slimming aids(減肥藥) at clinic.

Now scientists say that the key element, aristolochic acid酸, is responsible for the very high levels of kidney disease and urinary tract tumours in Taiwan. It's estimated估計 that about one in three of the population there have used herbal medicines containing含有 the toxin. The country has the world's highest incidence發生率 of cancers of the upper上 urinary tract - and in their study the scientists say more than half can be directly linked to the ingredient成分.

While products containing aristolochic acid are banned禁止 in many countries, one of the big concernse關注 is China. In 2004 a study suggests Chinese farmers produce enough of the plant to dose 100 million people. Scientists are concerned擔心 that in the decades to come, disease caused by the aristolochia will create an international public health problem of considerable相當 magnitude.大小規模

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http://www.bbc.co.uk/worldservice/learningenglish/language/wordsinthenews/2012/04/120412_witn_herbal_medicine.shtml