Ginkgo Biloba Under Attack

Imagine this: The government conducts a study with 230 healthy volunteers by giving them 15 cigarettes to smoke every day for 60 days, and then comes to the conclusion that cigarettes do not cause lung cancer, cardiovascular disease, emphysema or asthma because none of the participants developed these symptoms.

You would probably agree that this is a foolish conclusion. As we all know from empirical evidence knowledge based on experience through practice smoking causes these diseases only over a much longer period of time.

But recently a study on ginkgo biloba conducted in the same fashion intended to prove that ginkgo has no effect on improving memory, attention and cognitive clarity. This study was published Aug. 21, 2002, in the Journal of the American Medical Association (JAMA), and all major newspapers picked up the story with a certain attitude. "Now you have it," they seemed to say. "Ginkgo isn't a get-smart drug after all."

I have real trouble with this report, as ginkgo was never advertised or sold as a "get-smart drug" in the first place. But the press is always looking for sensational news to embellish.

As to the study itself, an article in our May issue stated, "[Ginkgo] leaves are used in traditional Chinese medicine for a number of old-age symptoms related to circulatory disorders in the capillaries, the fine arteries of the brain. Memory loss is the most common symptom. Eyes and limbs will also be affected when the blood flow is obstructed." Buildup of these abnormal obstructions takes place over years, and it would definitely be longer than 60 days to remove them. Naturopathic doctors know this, and the authors of this particular JAMA study acknowledge that their "study has limitations" and that "higher doses of ginkgo biloba over a longer period of time may yield different results."

In an interview, Dr. Solomon agreed his study should not be the final word on ginkgo. It lasted only six weeks, and more research is needed. Nevertheless, ginkgo now has a black mark next to its name.

There are two more problems I see with this study. First, Dr. Solomon said, "This study is the first rigorous test of ginkgo, which involved only healthy people." Isn't this ironic? How can I find out if a medicine works when it is only tested on healthy people?

Second, the study looked at only one brand, Ginkoba, made by Pharmatron, a division of Boehringer Ingelheim Ltd. of Germany. "The manufacturer of this brand claims they have the purest form and the highest potency," Dr. Solomon said. However, the "purest" form isn't always the most effective. We know this from vitamin E, where the distillation process involves 13 stages to isolate the purest form, d-alpha tocopherol. Only after many clinical applications was it discovered that the bio-availability of the purest form wasn't as good as the form with mixed tocopherols.

In natural medicine, things often work best in synergy.

"While this study shows that ginkgo did not have an effect on elderly adults with impaired mental function, there are more current well-designed studies that arrive at directly contradictory conclusions," said Phil Harvey, PhD, director of science of the National Nutritional Food Association in response to the JAMA study. Indeed, more than 300 German studies have been conducted since the Second World War confirming ginkgo's ability to remove blockages in the capillaries, thereby increasing blood flow and providing more oxygen to the cells.

"Let's not forget that over half a century of controlled trials have clearly demonstrated that those with mild to moderate memory problems and poor concentration symptoms, often associated with Alzheimer's, are helped by taking ginkgo," said Steven Dentali, vice-president for scientific affairs of the American Health Products Association.

At press time, I have not heard a reaction to this study from the government's Health Products and Food Branch in Ottawa. I wonder what to expect. Another foolish attempt to ban one more herb, this time ginkgo, just as they recently banned kava kava?