From Smart Drugs and Nutrients:
Ginkgo biloba is the oldest species of tree known, dating back 300 million years. Extracts from the leaves of the ginkgo biloba tree have been used by Chinese medicine for thousands of years. European physicians write over 1.2 million prescriptions per month for it. Ginkgo biloba is used to improve cerebral circulation, mental alertness, and overall brain functioning.
More than 34 human studies on ginkgo have been published since 1975, showing that ginkgo works by increasing blood flow throughout the body and brain. Ginkgo increases the productions of adenosine triphosphate (ATP, the universal energy molecule). It also improves the brain's ability to metabolize glucose, prevents platelet aggregation inside arterial walls by keeping them flexible, improves the transmission of nerve signals, and acts as a powerful antioxidant.
Ginkgo biloba leaf is effective for people with symptoms of reduced blood flow to the brain and extremities. It has been shown to be helpful with many of the complaints of the elderly such as: memory loss, slow thinking and reasoning, depression, dizziness, ringing in the ears, headaches, and senile macular degeneration (a major cause of blindness).
One study even shows significant improvement in people who have both Parkingson's and Alzheimer's disease. In this study 25 people w/ Parkingson's disease and signs of Alzheimer's disease were given ginkgo extract daily for one year. They were tested with standard tests, clinical evaluations, and a new computerized EEG. The scores improved significantly.
CITE: Funfgeld, E.W. "A natural and broad spectrum nootropic substance treatment of SDAT - the gingko biloba extract".
from Progress in Clinical and Biological Research, 1989, 317 (pp 1247-1260)
One study does not prove that Gingko biloba is efficacious in the treatment of these diseases. However, ginkgo is safe, inexpensive and easily obtained, and people with Parkingsons and/or Alzheimer's might consider experimenting with it.
PRECAUTIONS: No negative effects have been reported in the literature even in very large quantities.
DOSAGE: Most research has been done with a gingko biloba extract which contained a 24% concentration of flavinoid extract. At this strength, the usual dosage is 120-160 mg per day taken in three divided doses. However, many gingko products are lower in potency, and may require dosages as high as 1000 mg per day. Three to six months is probably needed to evaluate the results.
BIBLIOGRAPHY: "Smart Drugs and Nutrients" by Ward Dean & John Morgenthaler (1990)
ISBN# 0-9627418-9-2 ($12.95)
"Smart Drugs II" by Ward Dean / John Morgenthaler / Steven Wm. Fowkes (1993)
ISBN# 0-9627418-7-6 ($14.95)
SD2 covers totally different material than the first book:
Deprenyl, Melatonin, Milacemide, Nimodipine, Phosphatidylserine, Pregnenolone, Ondansetron and Zatosetron.
The first book has almost everything else you've ever heard of:
Pyrrolidone types (Piracetam, Oxiracetam), Hydergine, Vasopressin, Fipexide, Vinopocetine, Acetyl-L-Carnitine, Centrophenoxine, Choline, AL721, DHEA, DMAE, Gerovital GH-3, Ginkgo, Ginseng, Idebenone (CoQ10), Phenytoin (dilantin), Inderal, Vincamine, etc.