Le Bars et al., 2000

Dementia (uncomplicated Alzheimer’s disease or multi-infarct dementia)

Double-blind, placebo-controlled, fixed dose, parallel-group, multicenter study

Ginkgo biloba extract (EGb), 120 mg dose (40 mg t.i.d.), 26-week treatment

Compared to baseline, the placebo group had a significant 1.3 point increase on Alzheimer’s Disease Assessment Scale Cognitive Subscale (ADAS-Cog, p=0.01), while EGb group had a 0.7 point decrease at 26 weeks; the difference of 2 points between the two groups was significant (p=0.007).

n=224

Compared to baseline value of the Geriatric Evaluation by Relative’s Rating Instrument, the placebo group had a worsening of 0.06 points, while the EGb group had an improvement of 0.06 points (p=0.02). The placebo group’s mean rating on the Clinical Global Impression of Change worsened compared to baseline (p=0.008), while the EGb group experienced no change; the difference between groups was not significant.

Over the course of the study, 87 patients reported 149 adverse events, of which 69 were mild, 60 were moderate, and 20 were severe. Of the 20 severe adverse events, 13 were reported by patients in the EGb group, 7 by patients in the placebo group. Adverse events were distributed equally between the two groups, except those related to gastrointestinal system, which occurred more frequently in EGb group.

Tier 2: Observational studies

Meta-analysis of 7 prospective cohort studies with data from individuals free of CVD or stroke at baseline (data from 6 cohorts)

Compared to subjects with the lowest amount of flavonoid consumption, those with the highest consumption had a significantly reduced risk of fatal or non-fatal stroke (pooled RR=0.80, 95% CI: 0.65–0.98, p=0.05). However, there was significant heterogeneity among the studies (54%, p=0.05) and publication bias (p=0.01).