Objective: To determine if a ginkgo biloba-containing supplement improves cognitive function and quality of life, alters primary hemostasis, and is safe in healthy, cognitively intact older adults.
Design: Four-month, randomized, double-blind, placebo-controlled parallel design.
Subjects/setting: Ninety men and women (age range 65 to 84 years) were recruited to a university clinic. Eligibility included those without dementia or depression, not taking psychoactive medications or medications or supplements that alter hemostasis.
Intervention: Ninety subjects were randomly assigned to placebo or a ginkgo biloba-based supplement containing 160 mg ginkgo biloba, 68 mg gotu kola, and 180 mg decosahexaenoic acid per day for 4 months.
Main outcome measures: Assessments included: six standardized cognitive function tests, the SF-36 Quality of Life questionnaire, the Platelet Function Analyzer-100 (Dade Behring, Eschbom, Germany), and the monitoring of adverse events.
Statistical analyses: Baseline characteristics and study hypotheses were tested using analysis of covariance. Tests were two-tailed with a 0.05 significance level.
Results: Seventy-eight subjects (87%) completed both baseline and 4-month testing (n=36 in placebo group, n=42 in ginkgo biloba group). At baseline, the participants' cognitive function was above average. One of six cognitive tests indicated significant protocol differences at 4 months (P=0.03), favoring the placebo. There were no significant differences in quality of life, platelet function, or adverse events.
Conclusions: These finding do not support the use of a ginkgo biloba-containing supplement for improving cognitive function or quality of life in cognitively intact, older, healthy adults. However, high baseline scores may have contributed to the null findings. The ginkgo biloba product seems safe and did not alter platelet function, though additional studies are needed to evaluate the interaction of varying doses of ginkgo biloba and ginkgo biloba-containing supplements with medications and supplements that alter hemostasis.