Cancer and Herbal Supplements, Part 1
Many people are curious about reports that certain herbal therapies may prevent or even cure cancer. Hundreds of books, newsletters, and websites offer information about botanical treatments, but much of the material is misinformation. To date, no herbal supplement has been shown to prevent or cure cancer. In fact, data are accumulating that some herbal formulations may be harmful.
Of course, many drugs in use today are derived from plants, but before a drug derived from a plant source can be released, the active compound—the chemical—in the plant is isolated and purified. Extensive testing is done to prove the effectiveness of the chemical, as well as to document any side effects or interactions with other drugs. These studies are expensive and extensive, but they must be done before drugs are released. All drugs, from all sources, are subjected to this process.
Etoposide and Taxol are two examples of plant-based drugs used to treat cancer. Their active chemical has been isolated and tested and the production of these drugs includes rigid quality-control measures. In this controlled situation, the drug is reevaluated for the balance of risk versus possible benefit derived, remembering that not every drug is appropriate for every person.
Under the Dietary Supplement and Health Education Act (DSHEA), manufacturers are not required to prove that dietary supplements, including herbal formulations, are safe or effective, nor are quality control requirements in place for such products. Under this act, the onus is on the Food and Drug Administration (FDA) to prove that the herb or other substance in question is harmful. However, manufacturers may not make promises about specific cures on the product label. In March 2003, the FDA proposed new regulations of dietary supplements in an effort to ensure that supplements contain exactly what the manufacturer claims they contain. This would place the responsibility on the manufacturer to prove that the product is not contaminated and contains the specified amount of active ingredient.
Botanical products bring with them special problems. One involves standardization. By this we mean that the active compounds in plants may vary both in amount and degree of concentration. Soil, weather conditions, and handling and storage are not standard across the industry. In the November 2005 issue, Consumer Reports magazine compared ten ginseng products and found that, while the amount of ginseng per tablet was the same in all ten products, the active ingredient, ginsenosides, varied from brand to brand. This means that these products did not act on the body in an identical way, because they were not identical products. In addition, ginseng contains an estrogenlike chemical that may cause breast enlargement (gynecomastia) in men and vaginal bleeding in women. It may also cause hypoglycemia (low blood sugar).
Got to Cancer and Herbal Supplements Part II