Like many others at midlife or beyond, Wendy Fink, a health educator in her 50s, was appalled at the way her memory kept conking out.
“I was having trouble getting words,” says Fink, who lives in Royalston. “I was feeling very stressed about this.” So she tried ginkgo, an herbal memory-booster that’s getting new respect in mainstream medicine, albeit for genuine dementia, not run-of-the-mill “senior moments.”
“It seems simplistic,” Fink says of her four-month trial of ginkgo last winter, “but my problem went away. I feel much clearer, brighter, more myself.” She has “no idea,” she adds, why the improvement has persisted although she no longer takes the ginkgo.
The fact that she can’t explain it is hardly surprising, given that there’s little evidence that ginkgo helps healthy people like Fink with age-related memory decline.
But the lack of evidence doesn’t seem to be deterring the hopeful, who last year spent $ 270 million on ginkgo, making it the third best-selling herbal remedy, after echinecea, the cold-fighter, and ginseng, the energy-booster.
Sales “took off” last fall, among both healthy folks and those with dementia, after the Journal of the American Medical Association published a study showing it improves mental functioning in people with dementia, says Thomas Aarts, executive editor of the Nutrition Business Journal in San Diego.
Even the government is intrigued. The National Institute on Aging and the Office of Alternative Medicine are jointly sponsoring a two-year study in 42 patients with Alzheimer’s disease at Oregon Health Sciences University.
The ginkgo tree responsible for all this is a natural wonder. It’s so ancient – its ancesters appeared 300 million years ago – it’s known as a “living fossil. And it’s so resistant to environmental toxins that it thrives in smoggy cities worldwide. And therein may lie its secrets.
The tree’s resistance to insects and toxins may stem from its chemical makeup, says Varro Tyler, a plant medicine specialist emeritus at Purdue University and co-author of “Rational Phytotherapy, a Physicians’ Guide to Herbal Medicine.”
Its two main constituents are the flavonoids, which gobble up free radicals (harmful byproducts of oxygen metabolism), and the ginkgolides, which inhibit a natural platelet activating factor and therefore make the blood less likely to form clots that can clog arteries.
Ginkgolides are devilishly complicated molecules. In fact, Harvard chemist Elias J. Corey, who won the 1990 Nobel Prize for developing a method to synthesize complex organic molecules, including ginkgolide B, recalls that he became interested in the ginkgo molecule precisely “because it was such a challenge.”
Because ginkgo seems to boost blood flow and combat free radicals, the German Commission E, a government-appointed panel that reviews herbal therapies, recommended it in 1994 for dementia-related memory deficits, dizziness, ringing in the ears.
Ginkgo may also help alleviate impotence caused by anti-depressant drugs, according to Tyler.
So far, there have been more than 100 studies on ginkgo by plant medicine scholars, including 36 German studies in the 1980s in which patients with declining intellectual function appeared to benefit from 120 to 160 milligrams a day of ginkgo extracts. German authorities later criticized these studies for not including measurements of daily functioning as well as symptoms of disease progression.
But two recent studies did include those measures. In 1996, a Berlin study of 156 patients with Alzheimer’s disease or stroke-related dementia showed that a particular ginkgo biloba extract called EGb761 was a modestly effective and safe treatment, at a relatively high dose of 240 mg a day.
Last year, in the JAMA study of 202 dementia patients that sent American sales soaring, Dr. Pierre L. Le Bars, executive research director at the New York Institute of Medical Research in Tarrytown, also found that extract modestly effective.
About 27 percent of patients responded to ginkgo, Le Bar says, about the same response rate that occurs with a prescription drug called Cognex and less than the 40 to 50 percent response rate to another prescription drug, Aricept.
Compared to a placebo or dummy drug, a relatively low dose of ginkgo (120 mg a day) is linked to slight improvements in intellectual function, social behavior, and mood, Le Bars found.
In other words, ginkgo is promising, but not dazzling.
In fact, the effects of ginkgo are “so minuscule that. . .they may mean little from a functional point of view,” adds Dr. Thomas Perls, a geriatrician at Beth Israel Deaconess Medical Center. “Ginkgo is barking up the right tree. I just don’t know if it’s the right dog.”
Still, it’s being taken ever more seriously by researchers.
Jerry Cott, head of adult psychopharmacology research at the National Institute of Mental Health, says ginkgo has been shown in test tubes to protect neurons. And data suggest, he says, that ginkgo “is potentially more effective than vitamin E,” which in high doses can slow progression of dementia symptoms.
But there’s no evidence yet that ginkgo can actually prevent Alzheimer’s, “and that’s where we really need the answer,” adds Cott, who is helping the World Health Organization design a study to find out.
Marilyn Albert, director of gerontology research at Massachusetts General Hospital, agrees: “I’d be cautious, because the government does not oversee manufacturing of ginkgo and other products sold as dietary supplements. And this drug, like any other, might potentially interact with other medications.”
Still, barring reports of horrible side effects, the appeal of ginkgo is likely to continue to grow. So if you want to try it, start with 60 to 180 mg a day in divided doses, suggests Barry Taylor, a naturopathic doctor at the New England Family Health Center in Weston who says he’s recommended ginkgo to “hundreds” of patients.
But make sure the label says the capsules contain roughly 24 percent ginkgo flavonoids (also called flavonone glycosides) and 6 percent terpene lactones (also called ginkgolides A, B and C and bilobalide, a related compound.)
Discontinue ginkgo if you get a rash or other allergy. And because ginkgo can make blood less likely to clot, don’t take it without consulting your doctor if you have a bleeding disorder or take blood-thinning drugs, including aspirin.