Herbal remedies containing aristolochic acids (AA) have been linked to liver cancer from samples collected in hospitals around the world. The dangerous compounds are found in the birthwort family of plants, which are commonly used in traditional medicine to “help” with childbirth and promote healing.

The study, published in Science Translational Medicine, found that in 78 percent of liver cancer samples collected in Taiwan showed a distinctive mutation consistent with AA exposure. The team looked at 98 samples of hepatocellular carcinoma, the most common type of liver cancer, and the most common cause of death in people with cirrhosis.

The team also looked for the particular AA signature in samples of hepatocellular carcinoma from different regions of the world. Around 47 percent of samples in China had AA mutation signatures, as did 13 percent of those in Korea. The values for North America, Japan, and Europe were 4.8 percent, 2.7 percent, and 1.7 percent, respectively. People are poisoning themselves with these herbal extracts around the world, but certain Asian countries are more affected than others.

We have known that AA are harmful to humans for a few decades and governments have been issuing warnings against their use. Ingesting AA has been linked to rapid kidney failure, as well as cancer in the urinary tract. Sadly, both of these conditions are extremely common in Taiwan.

Taiwan only bans some products made from the birthwort plant family, known scientifically as the Aristlochiaceae. Unfortunately, there is no outright ban on all AA-containing products, only specific species of birthwort are regulated.

The data show that there was no change in the number of AA-induced cancerous mutations after some birthwort substances were banned in Taiwan. This might mean that people are still ingesting products containing AA or that it might take a bit longer for the number to drop. The latter would compare to how lung cancer numbers dropped long after the connection to smoking was revealed.

The researchers think that the best approach to reducing the instances of cancer is to ban AA-containing products altogether. They also proposed some ideas aimed at secondary prevention for when people have already been exposed.

People need to be aware of what exactly is in alternative medicine remedies. And remember just because something says herbal, it doesn’t mean that it’s not going to harm you. Hemlock is a plant too.