Which clinical trials support Ginkgo biloba or phosphatidylserine for memory enhancement in older adults?

1. The largest negative trial: GEM found no prevention of decline

The Ginkgo Evaluation of Memory (GEM) Study randomized 3,069 community-dwelling older adults (ages 72–96) to Ginkgo biloba 120 mg twice daily or placebo with a median follow-up of 6.1 years and concluded Ginkgo did not reduce the incidence of Alzheimer disease or dementia nor slow cognitive decline overall, a high-quality null result that anchors the field ^{[1] [2]}.

2. Short-term and smaller trials: mixed signals, some acute benefits

Smaller randomized trials and acute dosing studies report inconsistent findings: an acute study testing standardized Ginkgo biloba extract complexed with phosphatidylserine reported improved secondary memory performance and faster memory task speed across post-dose sessions compared with Ginkgo alone, suggesting formulation and complexation can modify short-term cognitive effects ^[3]. By contrast, other controlled trials of Ginkgo in older adults over weeks to months often failed to show meaningful improvements on neuropsychological batteries ^{[5] [1]}.

3. Phosphatidylserine trials in mild cognitive impairment: promising but formulation-dependent

A recent randomized, double‑blind, placebo‑controlled trial in Tianjin recruited 190 older adults with mild cognitive impairment (MCI) and administered a daily supplement containing 31.5 mg phosphatidylserine plus 3.6 mg Ginkgo flavonoids and other components for 12 months; investigators reported improvements in several cognitive domains, particularly short‑term memory, and biochemical changes consistent with the supplement’s hypothesized mechanisms—findings that support PS-containing interventions in MCI but cannot disentangle PS from the multi‑ingredient formula ^[4].

4. Systematic reviews and meta-analyses: benefit in impairment, not in healthy people

Reviews and meta-analyses conclude a pattern: Ginkgo biloba appears to have more consistent cognitive effects where impairment already exists (mild dementia/MCI), while it does not enhance cognition or prevent dementia in healthy older adults; reviews also note many trials are small, heterogeneous in dose and extract standardization, and at risk of bias, producing an overall evidence base that is equivocal and context-dependent ^{[6] [7] [8]}.

5. Animal and veterinary studies, industry claims, and marketing noise

Preclinical models and some veterinary trials (aged dogs) show cognitive improvements with combined nutraceuticals containing PS and Ginkgo, and commercial marketing frequently overstates translation to humans; such studies support biological plausibility but do not substitute for randomized human trials and are often cited by supplement makers as evidence for efficacy ^{[9] [10]}.

6. What this means for the claim “supports memory in older adults”

Clinical support exists for PS and Ginkgo when targeted at older adults with existing cognitive impairment or in specialized formulations (e.g., PS‑complexed Ginkgo or multi‑ingredient supplements), exemplified by the Tianjin MCI RCT and the acute PS‑complexation study, but the largest dementia‑prevention trial (GEM) and many well-controlled studies find no preventive or enhancing effect in healthy older adults; therefore any affirmative claim must be qualified by population (MCI vs healthy), formulation, dose, and study duration ^{[4] [3] [1] [2]}.

7. Key limitations and hidden agendas in the literature

Heterogeneity in extract standardization, PS source and dose, combination products, small sample sizes, short follow-ups, and industry sponsorship cloud interpretation; supplement manufacturers and promotional outlets cherry-pick positive, formulation‑specific trials while downplaying large null trials like GEM—readers should weigh high‑quality large trials and systematic reviews over single positive small studies ^{[1] [6] [10]}.