Herbs and Cancer

Introduction The herb pictured at the left, Aristolochia fangchi, has received attention recently because of its alleged link to kidney damage and the onset of cancer. This herb was a part of a Chinese herbal compound, used in a weight reduction treatment regimen, in Belgium, in the early 1990s. By 1993, instances of kidney failure were documented in patients who had received treatment (Depierreux, et al., 1994).

What Happened in Belgium? Greensfelder, in a short, readable article in Science (June 16, 2000), described the situation that occurred in Belgium in the early 1990s. At a weight loss clinic, between 1990 and 1992, a group of patients, who were primarily women, were prescribed a mixture of Chinese herbs and Western drugs. By 1993, instances of kidney failure were documented in the group of women patients who had received treatment (Depierreux, et al., 1994). By 1994, the first urinary tract cancers were detected among some of these same patients.

Kessler, in an editorial in The New England Journal of Medicine (June 8, 2000), discusses what investigators think happened to the herbal preparations that were used for weight loss. The preparations were supposed to contain the herbal products, Stephania tetrandra and Magnolia officinalis. However, pharmacists apparently used a derivative of the herb, Aristolochia fangchi, pictured above. The derivative, aristolochic acid, is known to be harmful to the kidneys of laboratory animals. The substitution of Aristolochia fangchi for Stephania tetrandra apparently occurred because of the similar sounding Chinese names of the two herbal products.

Nortier and colleagues described a study that was conducted on these Belgium patients and the conclusions that were drawn from it in an article published in The New England Journal of Medicine (June 8, 2000). The article itself is highly technical reading and is probably best appreciated by those who have specialized medical training. However, the short version is that, of the 105 patients who suffered from kidney disease, 43 had reached end-stage kidney failure at the time of the study. Thirty-one of the patients had already undergone successful kidney transplantation; 12 were undergoing kidney dialysis and were waiting for a kidney transplant.

Kessler, in the editorial that is mentioned above, outlines the limitations of the Nortier, et al., study. They include: the lack of a comparison group, the failure to consider other factors that may have caused the various types of cancer, and the failure to blind the pathologists to the hypothesis of the study. Because of these methodological limitations, the conclusion that is drawn by Nortier, et al., that the data suggest that aristolochia toxins "cause" kidney disease and urinary tract cancer, may be premature. There indeed may be a connection between this substance and kidney disease as well as cancer. However, because of the limitations of the study by Nortier, et al., it is difficult to agree that "cause" has been established.

Has Anything Similar Occurred in the United States? There has been no such tragedy in the United States. But what happened in Belgium has raised serious concerns about the safety and efficacy of herbal products and dietary supplements.

Under the Dietary Supplement Health and Education Act of 1994 (DSHEA), dietary supplements may bear "structure/function" claims without prior Food and Drug Administration (FDA) review. These are merely claims that the products affect the structure or function of the body. However, dietary supplements may not bear a claim that they can prevent, treat, cure, mitigate or diagnose disease without prior FDA review.

Continued to next post..