Survival Skills

Enlarge Image Image Gallery A ginkgo tree may live more than 1,000 years and grow to 195 feet tall with a diameter of up to 4 feet. This deciduous species was abundant worldwide during the Paleocene epoch but declined before the Ice Age, ­eventually surviving only in the mountain forests of ­eastern China. Gingko trees have been cultivated for ­centuries in the gardens of Chinese and Japanese temples. Botanists speculate that no truly wild ginkgo trees are now in existence.

IT SEEMS FITTING that Ginkgo biloba, a species of tree that thrived 65 million years ago and continues to thrive today, is used worldwide to treat conditions associated with aging. Sometimes referred to as a living fossil, a ginkgo tree can live for more than 1,000 years, a feat attributable to its resistance to disease, fire, and other environmental hazards.

Ginkgo as medicine

The Chinese treasured the ginkgo tree first for its food, considering the nuts (seed kernels) a delicacy. The first known use of ginkgo as a medicinal plant dates to 2800 b.c. Early on, ginkgo was thought to increase longevity and stamina largely because the tree itself was so hardy. (As a twentieth-century testament to its hardiness, the only tree to survive the atomic blast in Hiroshima was a ginkgo that sprouted from its base after its trunk was completely destroyed.) The Chinese also used seeds to treat venereal disease, asthma, lung congestion, diarrhea, and impaired hearing.

In the past half century, ginkgo has been extensively researched in Europe as a treatment for memory loss, dementia, stroke, asthma, and tinnitus (ringing in the ears). Today, European physicians prescribe ginkgo more often than any other herb or drug, with sales reaching nearly $500 million a year. Ginkgo appears to enhance health in three general ways:

q by improving circulation and oxygen metabolism;
q by preventing cell damage by free radicals;
q by reducing blood clotting.

Ginkgo leaves and roots contain flavone glycosides, which consist of a mix of bioflavonoids that are known antioxidants, including quercetin and kaempferol. Ginkgo also contains terpene lactones such as bilobalide and ginkgolides, which have been shown to protect nerve cells, keep blood from clotting, and improve blood circulation. Most of the 400-odd studies of ginkgo have used an extract of the leaf standardized to 24 percent flavone glycosides and 6 percent terpene lactones.

Mental health

Ginkgo extract is the best treatment known for inadequate blood flow to the brain caused by weakened blood vessels or impaired circulation due to an overproduction of platelet-activating factor (PAF), which activates immune cells responsible for ­inflammation and blood clotting. ­Restricted blood flow to the brain is extremely common among the elderly and is characterized by memory loss, decreased alertness, headaches, and depression.