Herbal Remedies May be “Global Health Hazard,” Commentary Suggests

In a commentary published in EMBO reports,  study authors present data showing that herbals containing Aristolochia species can cause aristolochic acid nephropathy (AAN). AAN can result in interstitial nephritis, renal failure, and urinary tract cancers. 

Aristolochia has been used for over 2,000 years but the inherent toxicities were not known until recent epidemiologic studies clearly showed the health risks linked to the common medicinal herbs. This reason for the recent toxic discovery is largely due to the latency period between Aristolochia exposure and onset of symptoms, as well as the genetic factors that confer susceptibility to about 5% of those exposed to Aristolochia. 

Initial recognition of the toxicity and carcinogenicity associated with Aristolochia surfaced in the early 1990s after about 100 otherwise healthy women from Belgium developed a rapidly progressing chronic kidney disease that required dialysis or a transplant. Study authors Doctors Donald M. Marcus and Arthur P. Grollman reported that according to a national prescription database, 8 million people in Taiwan were exposed to herbals containing Aristolochia. Data on patients with renal failure and cancer in Taiwan and China indicate that tens of millions of people are at risk of developing AAN. 

They also cited that other herbal remedies and traditional medicines may be causing severe adverse reactions in Africa and Asia though the epidemiological data are insufficient. 

Ingesting Aristolochia, particularly in genetically susceptible people, can lead to the formation of aristolactam and DNA complexes in renal tissues. These complexes can cause mutations in the TP53 tumor suppressor gene, which may start the progression to renal, liver, and bladder cancer.

“It is prudent to assume that many herbs may contain toxic or carcinogenic substances that can cause subsequent health problems for humans,” the authors concluded. The World Health Organization (WHO) currently encourage the use of traditional herbal remedies if they are of proven quality, but the study authors disagree with this stance as it does not mention the lack of scientific evidence supporting the efficacy of herbal remedies, or their known harms. They encourage more research to assess both short- and long-term efficacy of herbal remedies as well as the efficacy of “botanical products in widespread use.”

For more information visit embopress.org.