Thaindian News

Washington, Dec 22 (IANS) After several Chinese goods came under the scanner due to possible health hazards, now a new study says herbal products made in that country could increase the risk of urinary tract cancer.
Aristolochic acid, a carcinogen found in prescribed Chinese herbal products, including Guan Mu Tong, could trigger the cancer, according to the study.

Many countries, including Taiwan, have banned formulations containing aristolochic acid, because of clinical cases of urothelial (bladder) cancer owing to the acid’s use.

However, no such associations have been documented in herbal products containing aristolochic acid.

Jung-Der Wang of the Institute of Occupational Medicine and Industrial Hygiene, National Taiwan University (NTU), and his colleagues conducted a population-based study of patients newly diagnosed with urinary tract cancer, from Jan 1, 2001, to Dec 31, 2002.

They also looked at a random sample of the entire insured population from Jan 1, 1997, to Dec 31, 2002. There were 4,594 case patients and 174,701 control subjects in the final analysis.

The authors examined the association between having been prescribed Mu Tong, a herb that contains aristolochic acid, and urinary tract cancer, using data from the National Health Insurance reimbursement database.

Having been prescribed more than 60 gm of Mu Tong (possibly adulterated by Guan Mu Tong before being banned), or consumption of more than 150 mg of aristolochic acid, was associated with an increased risk of urinary tract cancer in a dose-dependent manner, said an NTU release.

The increased risk was independent of arsenic exposure (another risk factor for urinary tract cancer). “In addition to a ban on products that contain any amount of aristolochic acid, we also recommend continued surveillance of herbs or Chinese herbal products that might be adulterated with aristolochic acid containing herbs,” the authors write.

The findings were published in the Journal of the National Cancer Institute.