Benefits
Cognition and memory
In older adults with cognitive impairment or dementia, a pooled analysis of nine trials of the EGb 761 ginkgo extract found small gains in cognitive scores and daily activities over about six months, mainly at 240 mg a day. Memory benefits in healthy adults are not established, and GinPure itself has not been tested in these trials.
Long-term brain aging
Two large multi-year trials, one in 3,069 adults aged 75 and older and one in 2,854 adults aged 70 and older with memory complaints, found no benefit of ginkgo extract at 120 mg twice daily on the rate of dementia or Alzheimer's diagnosis compared with placebo.
Mechanism of action
Blood vessel effects
Ginkgo flavone glycosides and terpene lactones are studied for effects on blood vessel tone and blood flow. In people with leg artery disease, a Cochrane review of placebo-controlled trials found no clinically meaningful gain in walking distance.
Antioxidant flavonoids
Ginkgo flavone glycosides are antioxidant compounds; how much this contributes to effects on the brain in people is not known.
Clinical trials
Systematic review and meta-analysis of nine randomized placebo-controlled trials of the EGb 761 extract, 22 to 26 weeks long. (Tan et al. 2015, J Alzheimers Dis)
2,561 older adults with cognitive impairment or dementia.
EGb 761 improved cognitive change scores, daily activities and clinician global impression versus placebo, mainly at 240 mg/day. The Alzheimer's subgroup showed similar results to the whole group. No important safety concerns were found. These trials did not test GinPure.
Randomized, double-blind, placebo-controlled trial of ginkgo extract 120 mg twice daily, median follow-up 6.1 years. (DeKosky et al. 2008, JAMA)
3,069 community volunteers aged 75 or older with normal cognition (2,587) or mild cognitive impairment (482).
Ginkgo did not reduce the rate of all-cause dementia (hazard ratio 1.12) or Alzheimer's disease (1.16) compared with placebo, and did not slow progression in those with mild cognitive impairment. Side effect profiles were similar between groups.
Randomized, double-blind, placebo-controlled trial of EGb 761 at 120 mg twice daily for 5 years, funded by Ipsen. (Vellas et al. 2012, Lancet Neurol)
2,854 adults aged 70 or older in France who reported memory complaints to their doctor.
Ginkgo did not reduce progression to probable Alzheimer's disease compared with placebo (61 vs 73 cases; hazard ratio 0.84, not significant). Rates of adverse events, stroke and other bleeding or cardiovascular events did not differ between groups.
Cochrane systematic review of 14 randomized trials (739 participants) of Ginkgo biloba extract versus placebo. (Nicolaï et al. 2013, Cochrane Database Syst Rev)
Adults with intermittent claudication due to peripheral arterial disease.
In the 11 placebo-controlled trials (477 participants) that measured it, ginkgo increased the maximum walking distance by about 64 meters versus placebo, which was not statistically significant, and publication bias likely inflated the estimate. The authors found no evidence of a clinically significant benefit.