Ginkgo Biloba for Cognitive Function
Verdict: Counter-Evidence
Across 4 PubMed studies, the evidence for Ginkgo Biloba in Cognitive Function grades Tier D — counter-evidence. High-quality evidence indicates it is not effective (or is harmful) for this use.
D 🔴 D Counter-Evidence Counter-Evidence
Why this grade7-layer evidence engine
⚖️
Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditableRaw score 0.25
D
C
B
A
S
← counter-evidence / ineffectiveeffective / strong evidence →
Final grade
D · Counter-Evidence
Confidence
74%
Broadly consistent
Evidence level
E3
Single high-quality meta-analysis
▸View the full decision path (audit trail)
- compute_raw_score — 加權公式: L2×0.30 + L3×0.25 + L5×0.25 + L11×0.10 + L1×0.10 = 0.248
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高階證據未達主導 (0 positive vs 1 negative)，由 raw_score 決定
- tier_strict_requirement_check — Tier 條件達標，未降階
- detect_disputes — 偵測到 1 個 hard + 0 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status
PubMed studies (4)L2 · primary research & systematic reviews
Is Ginkgo biloba a cognitive enhancer in healthy individuals? A meta-analysis
Finding: G. biloba had no ascertainable positive effects on targeted cognitive functions in healthy individuals; effect sizes non-significant and near zero for memory (d=-0.04), executive function (d=-0.05), and attention (d=-0.08).
View on PubMed Ginkgo biloba for preventing cognitive decline in older adults: a randomized trial
Finding: GEM Study cognitive sub-analysis: annual rates of decline did not differ between G. biloba and placebo across any cognitive domain in community-dwelling older adults including those with normal cognition (P>.05).
View on PubMed Safety and efficacy of a ginkgo biloba-containing dietary supplement on cognitive function, quality of life, and platelet function in healthy, cognitively intact older adults
Finding: In cognitively intact older adults, the supplement did not improve cognition or quality of life; one of six cognitive tests showed significance favouring placebo (P=0.03). Appeared safe.
View on PubMed The effect of Ginkgo biloba on memory in healthy male volunteers
Finding: In healthy young male volunteers, nonsignificant treatment effects on all memory tests except the Sternberg Memory Scanning Test; extract was safe but largely ineffective at enhancing memory.
View on PubMed Regulatory & authoritative positionsL4/L5 · FDA / EMA / NIH ODS / Cochrane / Mayo …
L4a US FDA
Cautious
Most consider the main benefit of Ginkgo biloba to be its ability to prevent the worsening of memory problems due to … neurodegenerative disease. source↗
L4b EU EFSA
Not addressed
Some 'general function' claims (1548 botanical-related claims) have been put on hold pending for the Commission and Member States final consideration. source↗
L4c UK NHS
Cautious
Some people with dementia and their carers use complementary remedies, such as gingko biloba, curcumin or coconut oil. However, there's not enough evidence to say whether such remedies are effective. ... It's best to be wary of any products that claim to benefit people with dementia. If you're thinking of taking such a product or supplement, it's important to consult a doctor first. Some remedi… source↗
L4d TW TFDA / 衛福部
Cautious
銀杏果（俗稱白果）屬於一般食品，並無療效。而銀杏葉萃取物，在我國是以藥品管理。其效果僅限於改善末梢血液循環，對於老年失智、中風及動脈血管疾病，並未證實有治療效果。 source↗
L4e WHO
Neutral
WHO monographs on selected medicinal plants - Volume 1 source↗
L5a NIH Office of Dietary Supplements
Cautious
There's no conclusive evidence that ginkgo is helpful for any health condition. source↗
L5b Mayo Clinic
Against
Research doesn't support taking ginkgo to prevent or slow dementia or cognitive decline. source↗
L5d Harvard Health
Cautious
There is little evidence that ginkgo protects a person from developing the age-related memory impairment that bothers many people. source↗
L5e Specialty Society (condition-mapped)
Against
ginkgo was no better than a placebo in preventing or delaying Alzheimer's disease source↗