A few years ago I called a woman whose husband I was treating. I told her I wanted to refer him to a neurologist. "For his back?" she questioned. "No," I answered. "I am worried about his memory." (In fact, I was worried about Alzheimer's.) After a long pause, she said, "I have been too. And I have been asking him to see a doctor about it, but he just gets angry and won't go," to which I said, "I'll say I want him to see a neurologist for a second opinion on his back. After we make the appointment, we'll call you and you can call the doctor while he's on the way home." Our plan worked. My patient did see the neurologist, and sadly, our suspicions were confirmed. I put him on ginkgo biloba, but it did not seem to slow the progression of his condition.
Ginkgo Biloba
For quite a few years, ginkgo biloba has been promoted as a natural treatment to prevent or, in most cases, at least retard the progression of Alzheimer's disease. The literature supporting its use has been inconsistent. Alternative practitioners in the complementary health professions tends to emphasize and gravitate toward the positive studies, while traditional mainstream medicine tends to be more skeptical of smaller studies from less prestigious journals and point to the larger analyses, like the review of 36 studies comprising over 4,400 people with mental function loss. In that paper, the authors could not determine if ginkgo biloba was effective, although they did confirm its safety.1
Ginkgo and Memory: What the Latest Research Says
The Ginkgo Evaluation of Memory Study involved more than 3,000 subjects with a mean age of 79 years.2 The National Center for Complementary and Alternative Medicine and the Office of Dietary Supplements were the primary sponsors of this double-blind study. Both alternative and allopathic practitioners were anticipating the results. Subjects were given 240 mg of ginkgo biloba extract (120 mg b.i.d.), standardized to contain 24 percent ginkgo-specific flavone glycosides and 6 percent terpene lactones; or a placebo in the same packaging and taken in the same manner. The trial ran from 2000 until 2008 with a median follow-up time of six years.
Exclusion criteria included those with marked dementia, current use of antidepressants, low vitamin B12 levels and thyroid disease. Subjects with mild cognitive impairment based on published guidelines3 were not excluded. They comprised 15 percent of the 1,524 placebo takers and 16.5 percent of the 1,545 test subjects.
Participants received a battery of tests at baseline and took the Modified Mini-Mental State examination and Alzheimer's Disease Assessment Scale test every six months until 2004, and then annually along with 10 other neuropsychological tests. The results of the study are presented in Table 1. The scores are tabulated from numerous tests done by the authors. The smaller score indicates a slower rate of decline, which is a more favorable outcome.
