To the editor

The News feature on phytotherapeutic compounds sold as dietary supplements1 rightly criticizes the lax control on these products by the US Food and Drug Administration, but it goes too far when it suggests that they should be banned altogether. If such criteria were to be applied to the majority of pharmaceutical drugs presently approved, rarely would a medicine escape from being banned, including those sold over the counter. What we need is rational regulation, forcing manufacturers to clearly state side effects, dose-limited toxicity and drug interactions.

One of the phytotherapies cited in the article, for instance, was Gingko biloba. In spite of the increased risk of hemorrhage when the herb is taken indiscriminately (especially by patients submitted to surgery), several studies have shown the real benefits of Gingko biloba extracts in protecting DNA against both endogenous damage and chemical adducts—including those derived from environmental pollutants, accidental exposure to radioactivity or radiation therapy2,3.

In addition, patients with ocular and neurological degenerative disorders, hyperthermic brain injury, cerebral ischemia and vascular atherogenesis can also benefit from administration of Gingko biloba extracts4,5,6,7. One group has shown that 40 mg of Gingko biloba extract 761, taken orally three times a day for 2 months, reduced levels of DNA-damaging metabolites to those of the control group in 30 Chernobyl 'liquidators'—the technicians, workers and engineers sent to seal the plant after the Chernobyl disaster. After treatment, the protective effect lasted for 7 months, indicating that the extract need only be taken for a short time.

Yes, we should do more research on many of these 'dietary supplements', but we should also take a look at the already-published material worldwide. The Food and Drug Administration's criteria for common drugs sold over the counter should, in the short term, be applied to supplements in order to provide an informed orientation for users. On the other hand, the literature of the past decade indicates that these products deserve to be examined for both their potential benefits and dangers. After all, even aspirin can be harmful if misused.