In 1945, a few months after the A-bomb leveled Hiroshima, the blackened, apparently lifeless stubs of ginkgo trees near ground zero sprouted new leaves. Although in its 200 million years on Earth, the ginkgo tree had never before encountered a nuclear blast, it was well-equipped to survive the devastation. Ginkgo is indifferent to fire, resists bug infestation, and thrives in dirty, polluted air; some individual trees have been known to live for up to 1,000 years. Such tenacity has made the ginkgo the oldest living tree species on Earth, a living fossil preserved from days when dinosaurs plodded the terrain.
Delaying Fossilhood
The medicinal compounds found in this ancient and remarkable tree may enable you to avoid turning into a fossil yourself—or at least keep you from doing so prematurely. A concentrated extract of ginkgo leaves can intensify blood circulation, avert heart attacks and strokes, rev up the brain, and even delay the progress of dementia and Alzheimer’s disease. Thus, this mighty herb can help deter many of the afflictions associated with growing old.
Ginkgo biloba is the herb for an aging population, says Jennifer Brett, N.D., a naturopathic doctor at the Wilton Naturopathic Center in Stratford, Connecticut. Most of Dr. Brett’s older patients—those over 65—are taking supplements of ginkgo.
"People who are getting old worry about two things: Is my heart going to fail? Is my brain going to fail?" she explains. "In terms of prevention, this is an herb that people can take every day for the rest of their lives. It improves their general circulation and mental acuity."
In Europe, where botanical healing is common, many older people routinely take a ginkgo extract to improve their mental fitness. It is the most widely prescribed herb in Germany and has been approved in that country as a treatment for dementias, afflictions (including the type caused by Alzheimer’s disease) that are associated with loss of memory in older people.
It’s in the Leaf
Ginkgo is native to China, where the fruit and seeds have been used for 4,000 years to treat everything from asthma to problems with frequent urination and nocturnal emissions. The seeds and fruit are highly toxic, always require careful preparation, and need to be given in carefully measured doses to avoid poisoning. The leaves were rarely used as a medicine until a few decades ago, when European researchers concentrated dried leaves into an extract and discovered their remarkable medicinal properties.
Working with the extract, the researchers isolated two groups of active chemicals: flavone glycosides and a unique set of terpenoids that the scientists called ginkgolides. Over the years, an extract of 24 percent flavone glycosides and 6 percent ginkgolides became the standard used in scientific studies. Today, this formula, known as EGb 761, is used throughout Europe to treat heart disease, eye ailments, impotence due to low blood flow, tinnitus (ringing in the ears), poor circulation to the extremities, and head injuries and other brain-related conditions.
SUPPLEMENTSNAPSHOT
| Ginkgo Botanical name: Ginkgo biloba. May help: Heart disease, angina, stroke, intermittent claudication, depression, dementia, Alzheimer’s disease, Raynaud’s disease, Parkinson’s disease, head injuries, leg cramps, macular degeneration, tinnitus, impotence due to poor blood flow, clogged arteries, and diabetes-related nerve damage. Origin: Native to China; the oldest living tree species on Earth. Cautions and possible side effects: Avoid ginkgo if you are taking anticoagulants (blood thinners), aspirin or other nonsteroidal anti-inflammatory drugs, or antidepressant MAO inhibitor drugs such as phenelzine sulfate (Nardil) or tranylcypromine (Parnate). Taking more than 240 milligrams of concentrated extract may cause vomiting, diarrhea, or rash. Rarely, gingko may cause headache, stomachache, or other allergic reactions. |
Although doctors and scientists don’t fully understand how the chemicals in ginkgo work in the human body, the effects and benefits are pretty well known, says Alison Lee, M.D., a pain-management specialist and medical director of Barefoot Doctors, an alternative medicine practice in Ann Arbor, Michigan. "Ginkgo is really an important herb because there’s a lot of good research behind it," she says. "It works for many conditions."
Blood Flows like Water
Ginkgo is mostly known as a circulatory herb, or what doctors call a vasodilator. It widens blood vessels and holds them open so blood flow increases. While enlarging arteries and large veins, a vasodilator also expands capillaries, the tiny vessels webbed into your body tissues and organs.
This effect makes ginkgo especially useful for people who have cold hands and feet due to poor circulation. Dr. Brett routinely uses the herb to treat Raynaud’s disease, a severe constriction of blood vessels in response to cold. Raynaud’s sufferers literally can’t get blood to their fingers and toes, she says, but with the active chemicals in ginkgo, the blood vessels expand, allowing more warming blood to flow to the extremities.
Dr. Brett also prescribes ginkgo to people with diabetes who have lost feeling in their feet due to inflamed nerves and high blood sugar levels. Ginkgo stabilizes the blood flow, and its glycosides have strong anti-inflammatory properties. "I use it for any circulatory disorder," she says. If you have diabetes and want to consider using ginkgo, discuss it with your doctor.
Thinning Action
Increasing blood flow isn’t ginkgo’s only action. The ginkgolides apparently thin the blood by counteracting the effects of platelet activating factor (PAF), a chemical that causes blood platelets to stick together and clot.
Clotting, as you might imagine, is pretty important when you’ve sliced yourself with the potato peeler. But PAF also forms clots when there’s an irregularity in an artery, such as a chunk of fatty plaque sticking to the vessel wall, says Dr. Lee. "You want your platelets sticky when you get a wound, but you don’t want them bunching up around plaque in a blood vessel," she explains. "That’s going to create a blockage and reduce the flow of blood."
By thinning the blood, ginkgo may protect you from a stroke or heart attack, which can be triggered by a blocked artery or a blood clot that has broken away from an artery wall. In the same way, it may ease or prevent angina attacks—heart pain caused by constricted vessels—and pain due to cholesterol buildup in the vessels of your legs.
Thin blood will still clot, but it may take longer, says Dr. Lee. If you’re already on an anticoagulant (blood-thinning) medication or taking aspirin to reduce your risk of heart attack or stroke, you should be careful about using ginkgo. "If you’re already on a blood thinner, talk to your doctor," she cautions. "Two of my patients got nosebleeds after they started the ginkgo."
Platelets are not the only blood cells modified by ginkgo, adds Dr. Lee. There’s evidence that after several weeks, the herb eventually makes the membranes of red blood cells bend and stretch more easily. This effect may be important in increasing blood flow to the brain.
"If the membrane is more pliable, the cells can actually squeeze their way into tighter places, past blocked or partially blocked arteries and vessels," she says. "That may be very important in increasing blood flow, particularly in the small vessels in the brain."
Feed Your Head
The benefit of any increased blood flow is that your tissues and vital organs receive additional nutrients and oxygen. Increased blood flow to the brain has been shown to improve alertness, short-term memory, and the ability to concentrate. It may also relieve tinnitus, improve mood, and counteract depression.
Ginkgo not only feeds your head, it also improves the action of substances called neurotransmitters, which help carry signals between nerve cells. Influenced by the herb, these substances work more efficiently, so that messages travel from cell to cell more quickly. "This is an herb that can make you think better. It directly stimulates the brain," says Dr. Brett.
Ginkgo also apparently holds off or slows down the destructive consequences of an aging brain. Free radicals—the free-roaming, unstable molecules that invade cells and damage them—are natural metabolic by-products of aging. When someone has Alzheimer’s disease, the damaging effect of free radicals leads to more fat being deposited in brain cells. As that happens, those cells quickly become inoperative. Substances in ginkgo help to scavenge free radicals and slow down the rate at which fat is deposited, so the whole deterioration process is slowed.
Some research in Europe and the United States has shown that ginkgo can be helpful to people who have Alzheimer’s. For years, European studies have indicated that dementia patients taking ginkgo show signs of improvement. A few years ago, a U.S. study appeared to confirm these findings.
American researchers gave people with mild to moderately severe dementia 120 milligrams of EGb 761, the European ginkgo extract, each day for one year. Meanwhile, another group received an extract with no ginkgo (a placebo). After looking at the comparative results of treatment, researchers concluded that the ginkgo extract appeared to stabilize or, in some cases, improve mental functioning.
The researchers estimated that the ginkgo may have bought the patients a delay in the disease of between six months and a year. They note, however, that the treatment appears to work best in the early stages of the disease.
A Slow Process
For treating any condition, ginkgo takes time to build up in your system. You may have to take the herb for weeks before you begin noticing the benefits, says Dr. Lee. "I tell people to give it about six weeks," she says.
For long-term use, ginkgo is considered a relatively safe herb. Except at very high levels—more than 240 milligrams of concentrated extract—it usually produces no side effects.
Ginkgo is available in tablets and capsules, but the best way to take it is in tablets, says Dr. Lee. A standard dose is 120 milligrams a day. To avoid possible gastrointestinal discomfort, take one 40-milligram tablet three times a day.
At the drugstore or health food store, look for a supplement that contains 24 percent ginkgoflavoglycosides and 6 percent terpenelactones, says Dr. Brett. "Then you have the same concentration of the active ingredients that has been used in all the studies."
As for using ginkgo leaves, there’s no practical way to get a dose equivalent to what was used in studies. It takes about 50 pounds of leaves to get 1 pound of the extract in the appropriate percentages, says Dr. Brett.
