By Mark Blumenthal
In recent years much has been written and said about the effects of climate change and global warming. Much of this discussion has been characterized by controversy, criticism, and denial. Despite the length and breadth of articles on this vitally significant subject, little has been written about the effects of climate change on the future sustainability of medicinal and aromatic plants. In our cover story, ABC’s Courtney Cavaliere covers many geographic regions and consults numerous experts to present possibly the most cogent assessment of this situation to date.
On the clinical research front, there has been controversy in the past decade about the pros and cons of evidence-based medicine (EBM). While not wanting to get into the polemics of this issue (there’s simply not space), it is worth noting that numerous systematic reviews and meta-analyses of randomized controlled clinical trials (RCTs) continue to support the safety and clinical benefits of select herbs and phytomedicines.
In our Research Review section, we present two summaries of recent metaanalyses supporting clinical uses of two perennial favorites: garlic for lowering blood pressure and Asian ginseng—in this case, Korean red ginseng—for treating erectile dysfunction. Unfortunately, there was not enough space to include our review of the latest meta-analysis of RCTs on St. John’s wort for treating symptoms associated with mild-to-moderate depression. (An HerbClip covering this trial is accessible on the ABC Web site, www. herbalgram.org.) According to all 3 reviews, the bulk of the RCTs support the judicious use of preparations made from these herbs for the respective indications.
The November publication of the Ginkgo Evaluation of Memory trial in the Journal of the American Medical Association received predictably widespread media coverage. In this trial on over 3000 subjects (median age about 79 yrs), most of whom were cognitively intact, the administration of 240 mg per day of the world’s leading ginkgo extract (EGb 761®, W. Schwabe, Karlsruhe, Germany) did not prevent the onset of dementia or Alzheimer’s dementia after 6 years of use. Unfortunately, but predictably, much of the media overlooked the fact that no conventional pharmaceutical drug has shown efficacy in preventing these conditions, and that there are clinically documented benefits for using ginkgo extract, e.g., treating (not preventing) dementia (as well as treating peripheral arterial occlusive disease). In addition, the media did not report that controlled trials have shown that ginkgo extract has been as effective, and safer, as pharmaceutical drugs for such treatment.
This issue of HerbalGram also addresses big news on the regulatory front. In late December, the US Food and Drug Administration sent “no objection” letters regarding the GRAS (generally recognized as safe) affirmations of two proprietary stevia extracts produced by Cargill and Whole Earth Sweetener Co., respectively (the latter being a joint venture between Pepsi and Merisant, maker of Equal® brand aspartame). The result will be widespread availability of these, and eventually other, stevia-derived extracts as sweeteners in numerous consumer products. As discussed in the “Dear Reader” column of our previous issue, the safety of many sweeteners made from the South American stevia plant is impressive, and it was high time for the FDA to help millions of consumers gain further access to this safe, low-cost, natural, non-caloric sweetener by approving its use as a food additive. Stevia can become one of the best tools in the so-called war against obesity and its associated complications such as diabetes and related health problems.