Herbal remedies: They have poetic names and you can find one for every ailment, but they can also be dangerous – scientists from Singapore and Taiwan have now linked some to liver cancer.

The culprit is Aristolochic Acids (AA), a natural compound found in some plants used in herbal remedies for many purposes including weight loss and slimming. It is a known mutagen, which means it mutates many genes to cause cancers in humans.

AA has previously been implicated in kidney and urinary tract cancers, but recent findings by scientists from Duke-NUS Medical School, National Cancer Centre Singapore, John Hopkins Medicine Singapore and Chang Hung Memorial Hospital in Taiwan have revealed a decisive link between AA and liver cancers.

After sequencing the DNA of 98 liver cancers from Taiwan, the team led by Prof Steven Rozen from Duke-NUS found that more than three quarters of these cancers have high numbers of AA-related mutations.

Said Prof Hsieh Sen-Yung from Chang Gung Memorial Hospital, “Although we knew that there was exposure to AA in Taiwan, we were very surprised to find such a high proportion of liver cancer sufferers had exposure to AA.”

The team then looked at data on mutations from 1,400 live cancers from around the world and found that while AA is found in plants used in traditional medicine worldwide, there was a high prevalence of exposure in other parts of East and Southeast Asia.

While AA has been banned in Europe, Singapore and Taiwan, they are still readily available in China and the US. Furthermore, herbs containing AA are sometimes improperly labeled, making it difficult for consumers to be certain of the ingredients of multi-herb formulas.

The key to preventing exposure, in this case, is education and awareness.

Plants that may contain AA include Asarum plants (细辛, xì xīn), 马兜铃 (mǎ dōu líng), 青木香 (qīng mù xiāng). 天仙藤 (tiān xiān téng), 广防己 (guǎng fángjǐ), 关木通 (guān mù tōng), 寻骨风 (xún gǔ fēng), 朱砂莲 (zhū shā lián, also written as 朱沙莲).