Survived the Atomic Bomb, Planted in Every City, Buried in Every Pharmacy: The Lost Memory Tree

What is Ginkgo Biloba?

On August 6, 1945, the atomic bomb exploded over Hiroshima. At the Buddhist temple of Hosen-ji, about 1,130 meters from the hypocenter, the buildings were flattened in a breath. In the temple grounds stood a Ginkgo biloba, its leaves torn away and its trunk scorched. By any reasonable expectation, it was dead. The next spring, it budded. Hiroshima has a word for the trees that came through: Hibakujumoku, A-bombed trees. About 170 survived within two kilometers of the hypocenter, several ginkgos among them.

What survived Hiroshima had already survived almost everything else. Ginkgo biloba is the last living member of family Ginkgoaceae and the entire order Ginkgoales: a 200-million-year-old evolutionary lineage with fossils essentially identical to the living tree on every continent except Antarctica. It outlived the dinosaurs. Ice ages that buried continents. It is a botanical orphan: every relative it has ever had is extinct, and the species itself was nearly lost in the wild before being preserved for centuries in Chinese temple and monastery gardens.

Chinese herbals recorded ginkgo seeds from the Yuan dynasty (14th century). In 1505, the Ming-Dynasty physician Liu Wentai entered the leaf into an imperial materia medica, the Bencao Pinhui Jingyao. In 1965, Dr. Willmar Schwabe in Germany introduced a standardized leaf extract, later refined as EGb 761 (24% flavonoid glycosides, 6% terpene lactones, <5 ppm ginkgolic acids), and over the following decades that extract was tested head-to-head against donepezil (Aricept), one of the most prescribed Alzheimer's drugs. The 2006 Italian and 2009 triple-arm trials reported the same finding: EGb 761 performed comparably to donepezil for mild-to-moderate dementia. The large GEM trial (2008) found it does not prevent dementia. The European Medicines Agency recognized ginkgo leaf extract as a well-established medicine for mild dementia in 2015. The US Food and Drug Administration still classifies it as a dietary supplement, which means doctors cannot prescribe it and insurance will not cover it. The tree grows in nearly every American city, lining streets and parks. Most Americans have never been told it is a licensed medicine across the Atlantic.

Hiroshima, 200 Million Years & the 1505 Imperial Materia Medica

August 6, 1945: The Hibakujumoku

August 6, 1945. Hiroshima, Japan. The atomic bomb explodes over the city. At the small Buddhist temple of Hosen-ji, about 1,130 meters from the hypocenter, wood, paper and tile are flattened in a breath. In the temple grounds stands a ginkgo, its leaves torn away, its trunk scorched. By any reasonable expectation, it is dead. But in the spring of 1946, it buds. Hiroshima gave the survivors a name: Hibakujumoku, A-bombed trees. About 170 of them survived within two kilometers of the hypocenter, several ginkgos among them. When Hosen-ji was rebuilt, the builders refused to cut its tree and split the staircase around the trunk. And the tree raises a question the world still has not answered: what does this tree know about survival?

200 Million Years of Refusing to Die

The ginkgo did not just survive Hiroshima. Its lineage has survived for roughly 200 million years of fossil record. Fossils essentially identical to living trees have been found on every continent except Antarctica. It outlived the dinosaurs. Ice ages that buried continents. When every other species in its family died - and there were once many - the ginkgo endured. Today it is a botanical orphan: the sole living representative of an entire order of plants, preserved into the modern era largely because Buddhist monks planted it in temple courtyards, where the trees lived a thousand years and more.

The Yuan Herbals and Liu Wentai (1505)

The Chinese knew what they had. By the Yuan dynasty (14th century), the seeds appeared in Chinese herbals for coughs, wheezing and urinary complaints. The leaf came later: in 1505, the Ming physician Liu Wentai entered it into an imperial materia medica, the Bencao Pinhui Jingyao. Temples planted the trees. By the 1600s, when European explorers first encountered ginkgo in Japanese temple gardens, they found specimens already a thousand years old. Giants that had fed generations.

The Science: EGb 761, Aricept Trials & the Chernobyl Workers

1965: The EGb 761 Standardized Extract

In 1965, Dr. Willmar Schwabe in Karlsruhe, Germany, introduced a standardized ginkgo leaf extract, and from 1971, working with the French group that became Ipsen, sold the refined version later called EGb 761: specified to 24% flavonoid glycosides, 6% terpene lactones (ginkgolides A, B, C, and bilobalide), and less than 5 parts per million ginkgolic acids (the alkylphenols responsible for allergic skin reactions). Precise. Repeatable. Ownable. EGb 761 is the formulation behind Tanakan in France and Tebonin in Germany, and it is the extract used in essentially every controlled trial cited in this article.

The terpene lactones are the unusual part. Ginkgolides A, B, and C are diterpene trilactones found nowhere else in nature, and bilobalide is a sesquiterpene also unique to Ginkgo biloba. Ginkgolide B is a potent inhibitor of platelet-activating factor (PAF), which explains the documented effect on cerebral microcirculation. The flavonoid glycoside fraction provides antioxidant activity, and bilobalide has been shown in animal models to protect neurons against ischemic and hypoxic damage. Together they form a multi-compound profile that is genuinely difficult to reduce to a single mechanism, which is part of why head-to-head trials against single-molecule pharmaceuticals have been able to reach a draw.

2006: Italian Direct Comparison Against Donepezil

Ginkgo biloba extract versus donepezil, the blockbuster Alzheimer's drug sold as Aricept, versus placebo. Seventy-six patients with mild-to-moderate dementia. Twenty-four weeks. Double-blind study.

"No evidence of relevant differences in efficacy between EGb 761 and donepezil in the treatment of mild to moderate Alzheimer's dementia."

They worked about the same, and both beat placebo.

2009: Triple Comparison (Ginkgo, Donepezil, Combined)

Ninety-six patients with Alzheimer's and neuropsychiatric symptoms. Ginkgo, donepezil, or both combined. Twenty-two weeks. The result: similar effectiveness across all three groups, and the combination caused fewer side effects than donepezil alone.

2008: The Trial That Said No

Now the counterweight. The Ginkgo Evaluation of Memory (GEM) study, funded largely by the US National Institutes of Health, followed 3,069 people aged 75 and over for about six years. Half took 120 mg of EGb 761 twice daily; half took placebo. Ginkgo did not prevent dementia or Alzheimer's disease. Ginkgo is not a shield against dementia; it is a modest treatment for people who already have mild symptoms, in the same range as the drugs they would otherwise take.

The Price Spread

• Donepezil (Aricept): prescription drug; cost depends on brand, generic and insurance
• Prescription status: doctors can prescribe donepezil and insurance covers it; ginkgo is sold as a supplement in the US
• Ginkgo biloba extract: $10-30 per month retail - or free, if you know which tree

Chernobyl Recovery Workers

In 1995, French researcher Ingrid Emerit and Armenian colleagues studied 30 Chernobyl recovery workers: the men who worked in the reactor zone after 1986 and whose blood still carried clastogenic activity, substances that break chromosomes, years later. The dose: 40 mg of EGb 761, three times daily, for two months. The clastogenic activity in their plasma fell to control levels, and the effect lasted for months. A small study of a biomarker, not proof of protection from radiation sickness.

Why It Stays Buried: Female Trees, Corporate Capture & the FDA Trap

Round One: Urban Planning Removes the Females

Here is where the story fractures. The tree Chinese medicine used for centuries and the tree planted in every American city are not the same. Ginkgo trees are dioecious - either male or female. Males produce pollen. Females produce seeds enclosed in fleshy outer shells. And those shells smell. Butyric acid - the compound in rancid butter, in vomit, in decomposition. When female ginkgo seeds drop in autumn, sidewalks become unbearable. People complained. Cities listened. By the 1980s, urban foresters made a decision: plant only males. Cultivars with names like Autumn Gold, Lakeview, Princeton Sentry, Magyar. Guaranteed sterile. Guaranteed clean. Guaranteed no smell. In Seoul, South Korea, where about one in ten of the city's roughly 114,000 ginkgos is female, more than 440 workers have been sent out each autumn to strip the seeds before they fall, and the city has begun replacing female trees near bus stops with males. But they eliminated something else along with the smell: the medicine. In Chinese medicine, the seeds were recorded as medicine long before the leaf. Urban planning systematically erased half the tree's medicinal chemistry in the name of aesthetics. They bred the cure out to avoid the smell. Most people alive in North America today have never seen a female ginkgo.

Round Two: Schwabe Captures the Free Tree

Once Schwabe had EGb 761 - the formula, the trials - they owned the conversation. EGb 761 became a major European medicine, sold as Tanakan and Tebonin. Traditional Chinese Medicine had used whole leaves and seeds: simple preparations that preserved hundreds of compounds working together. The pharmacologists called that "unstandardized." They isolated the compounds they understood. They threw away the compounds they did not. Only corporations could afford the trials. Only corporations could prove efficacy under modern rules. Traditional preparation became "unscientific." Herbalists became "anecdotal." A tree that had grown freely in every climate now required pharmaceutical processing to be considered legitimate medicine.

Round Three: The FDA Supplement Trap

Here is the trap. The FDA classified ginkgo as a dietary supplement, not a drug. Doctors cannot prescribe it. Insurance will not cover it. It does not matter that European studies showed efficacy. It does not matter that the European Medicines Agency recognized ginkgo leaf extract as a well-established medicine for mild dementia in 2015. In the United States, it is a supplement. Supplements do not get prescribed. They do not get covered. They sit on pharmacy shelves next to multivitamins while patients pay for the prescription drug. The irony is surgical. Ginkgo grows in every city park. On every suburban street. Outside hospitals, outside nursing homes, outside the pharmacies selling Aricept. The medicine is planted everywhere. But the system made sure most Americans would never know.

Round Four: The Chernobyl Finding Stays in Journals

The 1995 Chernobyl-workers data is published and peer-reviewed. It is a small study of a blood marker, and nobody has followed it up with large trials. It is not taught in oncology rotations and not mentioned to patients walking into radiation therapy. The research stayed in journals. The tree stayed ornamental.

Four Suppressions, One Tree

None of these industries coordinated. They did not need to. Each acted in its own interest. Urban planners chose males to avoid complaints. Pharmaceutical companies standardized to own a product. The FDA labeled supplements as supplements. Each made the rational decision to maximize profit or minimize friction. The cumulative effect was total: a tree with 200 million years of survival, centuries of medical use, and modern clinical validation became invisible. Planted everywhere. Known by no one. Today an estimated 6 million Americans live with Alzheimer's disease. By 2050 that number will hit 14 million. The drugs slow decline. They do not stop it. They do not reverse it. They buy time. Meanwhile the ginkgo leaves continue to fall every November, a golden carpet that lasts two weeks before the city sweeps them away.

How to Identify, Forage & Use Ginkgo

Identification

Ginkgo is the easiest medicinal tree in the world to identify - it does not look like anything else. The leaves are unmistakable: bright green, fan-shaped, 2 to 4 inches across, with parallel veins fanning out from the petiole (no central midrib), and a distinct central notch that often divides the fan into two lobes (the biloba in the species name). They are arranged in small clusters along short woody spur shoots on older branches and singly on new growth. In autumn, the entire tree turns a uniform brilliant yellow-gold, then drops its leaves over a roughly two-week window - one of the most striking colour displays in any urban environment. The bark on mature trees is grey-brown, deeply ridged, almost cork-like. Mature size is 65 to 115 feet (20 to 35 m) tall. Female trees in autumn produce yellow-orange seeds about the size of a small plum, with a fleshy outer coat that smells strongly of rancid butter when ripe - this is how you tell male from female. Ginkgo has no close lookalikes in any North American or European urban landscape.

Foraging the Leaves

The best window is early to mid autumn, when the leaves are still green or just beginning to turn yellow at the edges. The flavonoid and terpene-lactone content is highest before the leaves are fully yellow and dropping. Take only the leaves you need from any one tree - removing 10 to 20 percent of the lower canopy does not harm a mature ginkgo. Critical sourcing rule: never harvest from trees you do not personally know to be untreated. Avoid trees next to busy roads, parking lots, dog-walking paths, and anywhere municipal landscape spraying happens. The same chemical-tolerance that makes ginkgo a popular street tree means it absorbs and stores the residues of whatever has been sprayed on or near it. The cleanest sources are private gardens, untreated park sections, and arboretums.

Alcohol Tincture (the Most Effective Preparation)

Most of the ginkgolides and bilobalide are poorly water-soluble, so a tea pulls relatively little of the active fraction. The traditional preparation that matches modern extract chemistry is an alcohol tincture. Chop a generous handful of fresh green ginkgo leaves coarsely, pack a clean glass jar half-full, and cover completely with 40 percent vodka or higher. Seal, label, and steep in a dark cupboard for 4 to 6 weeks, shaking every few days. Strain through cheesecloth into a dropper bottle. Typical adult dose: 1 to 2 mL (about half a dropper) one to three times a day, diluted in a small glass of water. Effect on circulation and mental clarity typically takes 4 to 6 weeks of daily use to become noticeable; this is consistent with the time course of EGb 761 in the clinical trials.

Tea (Lighter, but Useful)

A simple ginkgo tea is still worth making for the flavonoid fraction. Use 1 to 2 teaspoons of dried crumbled leaves per cup of water, simmer (not boil) for 8 to 10 minutes, strain. The flavor is mild and slightly nutty. The terpene lactones will be largely absent, but the flavonoid antioxidants are well extracted.

About the Seeds (Bai Guo)

The seeds of female trees - known as Bái Guǒ or "white nut" - have been a food and medicine in East Asia for millennia. Important: the fleshy outer coat must be removed (wear gloves; it contains the same compounds that cause poison-ivy reactions in sensitive people), and the inner kernel must be lightly roasted or boiled before eating. Raw seeds, or more than a small handful of cooked seeds in a day, are toxic. They contain 4'-O-methylpyridoxine (ginkgotoxin), a vitamin B6 antagonist, and seizures have been documented at high intake, particularly in children. Adult traditional culinary dose is around 5 to 10 cooked seeds per day, never more. People taking anti-epileptic medication should avoid ginkgo seeds entirely.

Safety & Drug Interactions

Standardized ginkgo leaf extract (with ginkgolic acids reduced to under 5 ppm) is generally well tolerated. Mild side effects include headache, dizziness, and gastrointestinal upset. The two important warnings: (1) Ginkgolide B has anti-platelet activity, so ginkgo can increase bleeding risk for people on warfarin, apixaban, aspirin, or any other anticoagulant, and should be stopped at least 2 weeks before any surgery. (2) Ginkgo seeds, raw or in excess, can trigger seizures (see above). Pregnant or breastfeeding women should avoid medicinal-strength preparations. People taking antidepressants (SSRIs/MAOIs), antiepileptics, or chemotherapy should consult a clinician before regular use. The leaf extract, harvested and prepared correctly, has a long-established safety record across millions of European prescriptions over the past 60 years.

Frequently Asked Questions

What is Ginkgo biloba and what is it used for?

Ginkgo biloba is a dioecious deciduous tree, the only surviving species in the family Ginkgoaceae, with a fossil record stretching back roughly 200 million years to the Permian and Triassic periods - it is one of the world's oldest living plant lineages. The fan-shaped, deeply notched leaves and the yellow autumn color make it instantly recognizable, and it has been planted as a street and temple tree across China, Japan, Korea, Europe, and North America. Chinese herbals recorded the seeds from the Yuan dynasty (14th century) for coughs and wheezing, and the leaf from 1505. The standardized leaf extract EGb 761, developed from a 1965 Schwabe extract, is licensed in Europe under names like Tanakan and Tebonin for age-associated cognitive impairment and mild dementia.

Does Ginkgo biloba actually work for memory and dementia?

Controlled trials of the standardized EGb 761 extract have shown effects comparable to donepezil (Aricept), one of the most prescribed Alzheimer's drugs. A 2006 Italian double-blind 24-week trial of 76 patients with mild-to-moderate dementia found no relevant difference in efficacy between ginkgo and donepezil; both beat placebo. A 2009 trial of 96 patients comparing ginkgo, donepezil, and the combination found all three groups improved about equally. But the large GEM trial (2008), which followed 3,069 people aged 75 and over for about six years, found ginkgo does not prevent dementia. The European Medicines Agency recognized ginkgo leaf extract as a well-established medicine for mild dementia in 2015. It is a modest treatment for people with mild symptoms, not a shield against dementia.

Why are the female ginkgo trees disappearing from city streets?

Ginkgo is dioecious: separate male and female trees. The female trees produce fleshy seed coats containing butyric acid - the same fatty acid that gives rancid butter, vomit, and decomposition their smell. When the seeds drop in autumn, sidewalks under a female tree become unbearable. Starting in the 1980s, urban foresters began planting only sterile male cultivars (Autumn Gold, Lakeview, Princeton Sentry, Magyar). In Seoul, South Korea, where about one in ten of the city's roughly 114,000 ginkgos is female, more than 440 workers have been sent out each autumn to strip the seeds before they fall. The aesthetic problem is real - but in Chinese medicine the seeds were recorded as medicine long before the leaf. Urban planning eliminated half of the tree's documented medicinal chemistry to avoid the smell.

Can I make ginkgo medicine from the trees on my street?

The fan-shaped leaves are easy to identify, abundant in autumn, and contain the same flavonoids and terpene lactones (ginkgolides A, B, C and bilobalide) that are concentrated in commercial EGb 761 extract - just at lower density and unstandardized. The traditional preparation is a tincture: pack a clean jar half-full of fresh chopped leaves harvested in early autumn (when the leaves are still green or just turning yellow), cover completely with 40 percent vodka or higher, seal, steep 4 to 6 weeks in a dark cupboard, then strain. Typical adult dose is 1 to 2 mL one to three times a day. A tea is possible but less effective because the terpene lactones are poorly water-soluble. Critical sourcing rule: harvest only from trees you know have NOT been chemically sprayed, away from busy roads, parking lots, and dog-walking paths. The seeds (with their butyric-acid pulp removed and the kernel briefly cooked) are also traditionally edible in small amounts, but raw or large quantities are toxic - see safety.

Is Ginkgo biloba safe? Any drug interactions or warnings?

Standardized ginkgo leaf extract (with ginkgolic acids reduced to under 5 ppm) is generally well tolerated; commonly reported side effects are mild headache, dizziness, and gastrointestinal upset. The two important warnings: (1) Ginkgo has mild anti-platelet effects through the ginkgolide B fraction, so it can increase bleeding risk for people on warfarin, apixaban, aspirin, or any other anticoagulant, and should be stopped at least 2 weeks before any surgery. (2) Ginkgo seeds contain 4'-O-methylpyridoxine (ginkgotoxin), which is a vitamin B6 antagonist; raw seeds, or more than a small handful of cooked seeds, can trigger seizures, particularly in children. Pregnant women should avoid medicinal-strength preparations. People taking anti-epileptic medication should avoid the seeds entirely. The leaf extract, harvested and prepared correctly, has a long-established safety record across millions of European prescriptions.