Plants of the Aristolochia genus have for centuries been used in Chinese herbal remedies, but they contain a naturally carcinogenic compound that causes mutations in the cells of people who consume them, according to two studies published in Science Translational Medicine today (August 7). The papers reveal that the compound, called aristolochic acid, causes more mutations than two of the best-known environmental carcinogens: tobacco smoke and UV light.
“A lot of people in the lay public assume that if something is herbal or natural that it is necessarily healthy,” said Marc Ladanyi, an investigator in the human oncology and pathogenesis program at Memorial Sloan-Kettering Cancer Center in New York who was not involved in the studies. “But this work very clearly shows that this natural plant product is extremely genotoxic and carcinogenic.”
Aristolochia has been in use in herbal remedies for a long while but the potential danger is a rather recent revelation. Cancers resulting from its use do not show up until many years later so the connection is not made. Therefore, it may continue to be used in Asian countries. Aristolochic acid has been banned in most countries since 2003 stemming from problems related to urothelial carcinomas of the upper urinary tract (UTUC) identified as being associated with the acid.
Aristolochia family of plants includes birthworts, pipevines and Dutchman’s pipes as commonly known. This wikipedia section has a rundown of its uses and known toxicity. For a more readable account, see Herbal Medicine and Aristolochic Acid Nephropathy « Science-Based Medicine.