Friday, December 25, 2009

When herbs are bad for you

Urinary tract cancer associated with Chinese herbal products containing aristolochic acid

The carcinogen aristolochic acid, which was found in many prescribed Chinese herbal products including Guan Mu Tong, is associated with an increased risk of urinary tract cancer, according to a new study published online December 21 in the Journal of the National Cancer Institute.

Many countries, such as Taiwan, have banned products containing aristolochic acid (Taiwan did in 2003), because of clinical cases of urothelial cancer in association with aristolochic acid use. However, no such associations, to the authors' knowledge, have been documented in herbal products containing aristolochic acid.

To examine this association, Jung-Der Wang, M.D., ScD, of the Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, at the National Taiwan University, and colleagues conducted a population-based case-control study of Taiwanese patients newly diagnosed with urinary tract cancer from January 1, 2001, to December 31, 2002. They also looked at a random sample of the entire insured population from January 1, 1997, to December 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, an herb that contains aristolochic acid, and urinary tract cancer using data from the National Health Insurance reimbursement database.

Having been prescribed more than 60 g of Mu Tong (possibly adulterated by Guan Mu Tong before banned), or consumption of an estimated amount of more than 150 mg of aristolochic acid was associated with an increased risk of urinary tract cancer in a dose-dependent manner. 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. "Finally, patients with a history of aristolochic acid nephropathy or consumption of Mu Tong or Fangchi before they were banned should be monitored regularly for urinary cancer."

Study limitations: Not all of the diagnoses were confirmed by histopathology reports. Subjects may have taken additional nephrotoxic herbs or agents that were not prescribed. Actual intakes of the prescribed herbal products recorded in the National Health Insurance reimbursement database were not validated. Smoking history was not taken into account.


Babyface wins race in longevity study

Good looks do have a general relationship with good health -- The possibility that it might reflect good genes is however avoided below -- predictably

PEOPLE who look young for their age are already the envy of their peers. But those holding back the years haven't just been blessed in the looks department. Scientists have shown looking younger than you are also means you will live longer. They suggest patients could give GPs a photograph of themselves since this would be as good a guide to their longevity as complicated testing.

University of Southern Denmark Professor Kaare Christensen tested the belief that a person's perceived age gave a general indication of health. His team looked at twins to see whether perceived age, or how old others think you are, was linked to survival and age-related traits such as physical functioning and brainpower.

"It's probably easy to explain because people who've had a tougher life are more likely to die early and their life is reflected in their face."


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