Traditional Chinese Medicines Linked to Cancer

Traditional Chinese medicines often exist in a legal, scientific, and ethical grey area. Despite concerns over ingredients sourced from protected animals and limited evidence of their effectiveness, the market in these products is still very, very large. And now, two new studies have looked at the health and legal implications of a number of these remedies, and have found some rather disturbing results.

Top image: Gnosis/John R. on Flickr.

The first of these was published in the Public Library of Science and is the result of genetic sequencing of 15 samples of traditional Chinese medicines seized at Australian borders. After analyzing what was actually inside the medicine, the researchers at Murdoch University found that there was a significant disparity from what the medicine was claimed to be.

Some of the medicines contained plants of the genus Ephedra and Asarum, both of which are toxic in high doses, and weren't labelled with concentrations. There were also products labelled as 100% of one thing, but actually containing another — such as that purporting to be Saiga antelope, but found to have considerable quantities of goat and sheep.

But by far the most worrying is the presence of protected species in the medicine, such as Asiatic black bear, and the aforementioned Saiga antelope.

Simultaneously, research published in PNAS has linked a popular ingredient in Chinese medicines to urethral cancer in Taiwan. Aristolochia plants have long been linked to herbal medicines, but are known to be severely carcinogenic. The plants contain Aristolochic acid, which reacts with DNA to form aristolactam (AL)-DNA adducts, which are renal lesions. These lesions are specifically linked to the plant, and this study links them to more than half the instances of disease. The increased popularity of medicines including these plants is linked to a mammoth spike in instances of the cancer in Taiwan over the last few decades, as as much 1/3 of the population has used drugs including the substance.

Both of these studies drive home how poorly understood the effectiveness is of many traditional Chinese medicines, and how little is done to prove their safety and ingredients. Without both better labeling and better research, it's hard to view them as anything but unsafe.