Chapters
Ginkgo (Ginkgo biloba) leaf extract is taken every day by millions of people hoping to protect their memory. The Institute's working monograph on ginkgo leaf puts that hope against the clinical grading, and this film walks through what it found.
The standardised extracts used in trials take about 50 kg of leaf to make 1 kg of extract, concentrating the flavone glycosides and terpene trilactones and washing out the ginkgolic acids. Basic tinctures and leaf powders skip that step, so they aren't the product the trials tested, and some products on the market are spiked or substituted (Sophora fruit is one known substitute). The film then covers the GEM trial, more than 3,000 older adults followed for about six years, which found no protection against dementia, the disputed evidence in people who already have cognitive impairment, and the bleeding risk with warfarin, dabigatran or high-dose aspirin. It ends on the history: ginkgo leaf for memory is a modern use, and the 1712 engraving shown is the earliest European picture of the tree.
