Cognitive performance, SPECT, and blood viscosity in elderly non-demented people using Ginkgo biloba.
Level 2 - randomized trial
Double-blind randomized controlled trial
PubMed 12905098 · doi:10.1055/s-2003-41197
What was done
In a double-blind, randomized, placebo-controlled trial, 48 non-demented men aged 60 to 70 years (matched for educational level) received either dried Ginkgo biloba extract or a placebo over an 8-month period. Participants were evaluated using a battery of neuropsychological tests, Single Photon Emission Computed Tomography (SPECT) for regional cerebral perfusion, and laboratory measures of blood viscosity.
What was found
The abstract provides no numerical data, effect sizes, or p-values. It reports that after 8 months, the Ginkgo biloba group demonstrated reduced blood viscosity, improved cerebral perfusion in specific brain regions, and improved global cognitive functioning. In contrast, the placebo group exhibited increased blood viscosity, decreased regional cerebral perfusion, and cognitive deterioration across several domains.
Why it matters
This study provides mechanistic and clinical evidence suggesting that Ginkgo biloba extract may mitigate age-related cognitive decline by concurrently lowering blood viscosity and enhancing cerebral blood flow.
Limits
The sample size was small (48 participants) and restricted exclusively to men aged 60–70, limiting generalizability to women and broader age ranges. The abstract does not report specific dosages, exact numerical outcomes, effect sizes, or statistical significance thresholds.
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