Dataset Information

Ginkgo biloba for prevention of dementia: a randomized controlled trial.

ABSTRACT:

Context

Ginkgo biloba is widely used for its potential effects on memory and cognition. To date, adequately powered clinical trials testing the effect of G. biloba on dementia incidence are lacking.

Objective

To determine effectiveness of G. biloba vs placebo in reducing the incidence of all-cause dementia and Alzheimer disease (AD) in elderly individuals with normal cognition and those with mild cognitive impairment (MCI).

Design, setting, and participants

Randomized, double-blind, placebo-controlled clinical trial conducted in 5 academic medical centers in the United States between 2000 and 2008 with a median follow-up of 6.1 years. Three thousand sixty-nine community volunteers aged 75 years or older with normal cognition (n = 2587) or MCI (n = 482) at study entry were assessed every 6 months for incident dementia.

Intervention

Twice-daily dose of 120-mg extract of G. biloba (n = 1545) or placebo (n = 1524).

Main outcome measures

Incident dementia and AD determined by expert panel consensus.

Results

Five hundred twenty-three individuals developed dementia (246 receiving placebo and 277 receiving G. biloba) with 92% of the dementia cases classified as possible or probable AD, or AD with evidence of vascular disease of the brain. Rates of dropout and loss to follow-up were low (6.3%), and the adverse effect profiles were similar for both groups. The overall dementia rate was 3.3 per 100 person-years in participants assigned to G. biloba and 2.9 per 100 person-years in the placebo group. The hazard ratio (HR) for G. biloba compared with placebo for all-cause dementia was 1.12 (95% confidence interval [CI], 0.94-1.33; P = .21) and for AD, 1.16 (95% CI, 0.97-1.39; P = .11). G. biloba also had no effect on the rate of progression to dementia in participants with MCI (HR, 1.13; 95% CI, 0.85-1.50; P = .39).

Conclusions

In this study, G. biloba at 120 mg twice a day was not effective in reducing either the overall incidence rate of dementia or AD incidence in elderly individuals with normal cognition or those with MCI. Trial Registration clinicaltrials.gov Identifier: NCT00010803.

SUBMITTER: DeKosky ST

PROVIDER: S-EPMC2823569 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:ContextThe herbal product Ginkgo biloba is taken frequently with the intention of improving cognitive health in aging. However, evidence from adequately powered clinical trials is lacking regarding its effect on long-term cognitive functioning.ObjectiveTo determine whether G. biloba slows the rates of global or domain-specific cognitive decline in older adults.Design, setting, and participantsThe Ginkgo Evaluation of Memory (GEM) study, a randomized, double-blind, placebo-controlled clinical trial of 3069 community-dwelling participants aged 72 to 96 years, conducted in 6 academic medical centers in the United States between 2000 and 2008, with a median follow-up of 6.1 years.InterventionTwice-daily dose of 120-mg extract of G. biloba (n = 1545) or identical-appearing placebo (n = 1524).Main outcome measuresRates of change over time in the Modified Mini-Mental State Examination (3MSE), in the cognitive subscale of the Alzheimer Disease Assessment Scale (ADAS-Cog), and in neuropsychological domains of memory, attention, visual-spatial construction, language, and executive functions, based on sums of z scores of individual tests.ResultsAnnual rates of decline in z scores did not differ between G. biloba and placebo groups in any domains, including memory (0.043; 95% confidence interval [CI], 0.034-0.051 vs 0.041; 95% CI, 0.032-0.050), attention (0.043; 95% CI, 0.037-0.050 vs 0.048; 95% CI, 0.041-0.054), visuospatial abilities (0.107; 95% CI, 0.097-0.117 vs 0.118; 95% CI, 0.108-0.128), language (0.045; 95% CI, 0.037-0.054 vs 0.041; 95% CI, 0.033-0.048), and executive functions (0.092; 95% CI, 0.086-0.099 vs 0.089; 95% CI, 0.082-0.096). For the 3MSE and ADAS-Cog, rates of change varied by baseline cognitive status (mild cognitive impairment), but there were no differences in rates of change between treatment groups (for 3MSE, P = .71; for ADAS-Cog, P = .97). There was no significant effect modification of treatment on rate of decline by age, sex, race, education, APOE*E4 allele, or baseline mild cognitive impairment (P > .05).ConclusionCompared with placebo, the use of G. biloba, 120 mg twice daily, did not result in less cognitive decline in older adults with normal cognition or with mild cognitive impairment.Trial registrationclinicaltrials.gov Identifier: NCT00010803.

Project description:OBJECTIVES:The aim of this randomized, double-blind, placebo-controlled trial was to determine the efficacy and safety of Ginkgo biloba extract in patients diagnosed with vascular cognitive impairment (VCI). METHODS:A total of 90 patients (aged 67.1±8.0 years; 59 women) were randomly allocated (1:1:1) to receive G. biloba 120 mg, G. biloba 60 mg, or placebo during a 6-month period. Assessment was made for efficacy indicators, including neuropsychological tests scores (Sandoz Clinical Assessment Geriatric Scale, Folstein Mini-Mental State Examination, Mattis Dementia Rating Scale, and Clinical Global Impression) and transcranial Doppler ultrasound findings. Safety indicators included laboratory findings, reported adverse reactions, and clinical examination. RESULTS:At the end of 6-month study period, G. biloba 120 and 60 mg showed a statistically significant positive effect in comparison with placebo only on the Clinical Global Impression score (2.6±0.8 vs 3.1±0.7 vs 2.8±0.7, respectively; P=0.038). The Clinical Global Impression score showed a significant deterioration from the baseline values in the placebo group (-0.3±0.5; P=0.021) as opposed to G. biloba groups. No significant differences were found in the transcranial Doppler ultrasound findings. Adverse reactions were significantly more common and serious in the placebo group (16 subjects) than in either of the two G. biloba extract groups (eight and nine subjects, respectively), whereas laboratory findings and clinical examinations revealed no differences between the groups receiving G. biloba extract and placebo. CONCLUSION:According to our results, G. biloba seemed to slow down the cognitive deterioration in patients with VCI, but the effect was shown in only one of the four neuropsychological tests administered. However, because of this mild effect in combination with a few adverse reactions, we cannot say that it is ineffective or unsafe either. Further studies are still needed to provide unambiguous evidence on the efficacy and safety of G. biloba extract.