Aspiring tycoons aren’t the only ones fretting over their memories. Life in the Information Age strains everyone’s processing capacity–and countless Americans are turning to supplements to improve, or at least preserve, whatever they’ve got. Ginkgo sales have exploded recently (reaching more than $100 million last year), and it’s just one of many substances now being peddled, and gobbled, as brain tonics (chart). Mixtures with brand names like Mental Edge, Neuroboost and Clear Thoughts now crowd the shelves of health-food stores–along with candy bars dubbed Think and Smart. Could any of this stuff actually work? A new study, published in last week’s Journal of the American Medical Association, offers some of the best evidence yet that it could. The study showed that a daily regimen of ginkgo biloba extract can briefly stabilize or even improve mental performance in people mildly impaired by Alzheimer’s and other forms of dementia. But the treatment is far from curative, and the medical world is still bitterly divided on whether healthy people can gain anything from it.
Ginkgo biloba has been a staple of Chinese medicine for nearly 4,000 years, but its use in the West dates back only a couple of decades. In Germany, where ginkgo is regulated and sold as a drug, doctors prescribe it for several conditions, including mild dementia, and the rationale is solid. Memory involves exquisitely precise interactions among billions of neurons, and it’s easily disrupted. Vascular disease can deprive neurons of the blood and oxygen they need to interact properly. Oxidation (the chemical reaction that ages all our tissues) can wither them. And Alzheimer’s disease can turn whole networks of neurons into gumballs. Ginkgo biloba doesn’t stop these processes, but it may enhance cerebral blood flow by dilating arteries and capillaries. Like vitamins C, E and beta carotene, it may also combat oxidation.
To gauge the herb’s effects on mild dementia, researchers at six U.S. medical centers had 309 patients take either 120 milligrams of ginkgo biloba extract or a placebo every day for periods of up to a year. After six months, 27 percent of the ginkgo users–but only 14 percent of those taking sugar pills–showed moderate improvement on cognitive tests. Likewise, questionnaires completed by the patients’ family members indicated that 37 percent of the treatment group (compared with 23 percent of the placebo group) were faring better in daily life. The effects were roughly comparable to those achieved with tacrine, a prescription drug approved four years ago as a treatment for Alzheimer’s. Both treatments effectively stalled the disease process for six months. But tacrine costs more than four times as much as ginkgo ($4.20 a day versus $1 a day), and it’s far more toxic. In clinical studies, a fourth of all tacrine users have developed potentially dangerous liver abnormalities. By contrast, minor stomach upset was the only side effect seen in the ginkgo study.
The effects were admittedly modest, but the changes in people’s lives were often substantial. Sam Belf, a 71-year-old retired schoolteacher from the Bronx, N.Y., was increasingly forgetful when he enrolled in the study in 1991. The cause was unclear, but his physician suspected he might be developing Alzheimer’s. Belf has taken ginkgo ever since, and though he still gropes for phrases and phone numbers, he says his memory has improved. During his years on the herb, he has developed a science program for kids and written a yet-unpublished book. ““I’m more relaxed,’’ he says. ““There’s no cloud.''
Ginkgo isn’t the only natural substance showing promise as a brain saver. Recent studies suggest that women who take estrogen after menopause are less prone to Alzheimer’s (the hormone seems to stimulate the growth of neurons) and that vitamin E can slow the progression of the disease, apparently by protecting cells from oxidative damage. Preliminary studies suggest that people with mild dementia may also benefit from supplements of acetyl L-carnitine (ALC) and phosphatidylserine (PS), natural compounds that are synthesized within the body to foster communication among neurons. Whether any of these agents can sharpen healthy minds is still an open question. But where ginkgo is concerned, it’s a reasonable inference. ““We know it enhances the flow of blood and oxygen into the brain,’’ says Rob McCaleb, president of the Colorado-based Herb Research Foundation and a member of the presidential commission on supplement labeling. ““You don’t have to be impaired to benefit from that.''
Dr. Dharma Singh Khalsa, a Tucson, Ariz.-based anesthesiologist, takes that argument a step further. In his recent book ““Brain Longevity’’ (454 pages. Warner Books. $25), Khalsa contends that by taking various herbs, vitamins and amino acids, we can not only improve our minds but keep them from declining with age. ““Alzheimer’s disease and other types of cognitive decline are not something you wake up with one day,’’ he says. ““These illnesses can develop over 40 years.’’ There is some evidence that estrogen and anti-inflammatory drugs such as ibuprofen may reduce a person’s long-term Alzheimer’s risk. But it’s not yet clear whether that potential payoff outweighs the hazards of taking such medications for long periods. And there’s no direct evidence that other supplements can prevent mental decrepitude. ““We’re all desperate to live longer, or improve our memories, or stave off Alzheimer’s,’’ says Rudy Tanzi, director of the genetics and aging unit at Massachusetts General Hospital. ““But to think you’re going to do it with a handful of supplements is just a pipe dream. Somebody has figured out how to make a lot of money selling big promises for nonprescription compounds.''
Fortunately, most of the purported brain nutrients flooding health-food stores are harmless. Tanzi worries that DMSO (a solvent), L-pyroglutamic acid (an amino acid) and magnesium (a mineral) could prove dangerous in large doses. But he considers vitamin E supplements a reasonable investment, and he takes a little ginkgo himself. Tanzi has no illusions about supercharging his brain, but Greg Arrese still believes that his is getting sharper. And as any memory coach will tell you, trusting your recall is one way to strengthen it.
Ginkgo biloba: This herbal extract may enhance cerebral blood flow and prevent cell damage. Clinical trials show it can help alleviate mild forms of dementia.
Phosphatidylserine (PS): The body produces this lipid to keep brain cells’ membranes porous and flexible. Studies suggest that synthetic PS, made from soy lecithin, can slow age-related memory loss.
Acetyl L-carnitine (ALC): This natural body chemical stimulates the release of acetylcholine, a neurotransmitter critical to learning and memory. European studies suggest synthetic ALC can help offset memory loss caused by age, Alzheimer’s or alcoholism.
DMAE: This nutrient fuels production of acetylcholine. Proponents say supplements boost mood and concentration, but hard evidence is lacking.
Vitamin E: Besides protecting the heart and boosting immunity, this antioxidant may slow progression of Alzheimer’s. Researchers suspect it has protective effects on neurons.
Ibuprofen: Recent studies suggest that regular users of anti-inflammatory drugs lower their long-term risk of Alzheimer’s.
