Gingko Biloba (Ginkgo biloba)

Ginkgo biloba is a traditional Chinese medicine containing flavonoids and terpenoids that enhance cerebral blood flow and neuroprotection. Clinical studies show it significantly improves cognitive function in Alzheimer's patients and enhances daily living activities in mild dementia.

Origin & History

Ginkgo biloba is a deciduous tree native to China, belonging to the Ginkgoaceae family. The leaves are harvested and processed into extracts like EGb 761 using aqueous-ethanol extraction, yielding flavonoids and terpene lactones.

Historical & Cultural Context

Ginkgo biloba has been used in Traditional Chinese Medicine for centuries to address cognitive impairment and dementia. Its use in TCM aligns with its modern application as a cognitive enhancer.

Health Benefits

• Improves cognitive function in Alzheimer's patients (RR=1.98, 95% CI 1.52-2.59, P<0.001) [1]. • Enhances activities of daily living in mild dementia (p=0.01) [3]. • Increases clinical effectiveness when combined with donepezil in Alzheimer's (RR=1.23, 95% CI 1.13-1.34, P<0.00001) [2]. • Reduces positive symptoms in schizophrenia [6]. • Provides neuroprotection and antioxidant benefits due to flavonoids and terpene lactones [3][6].

How It Works

Ginkgo biloba's active compounds include flavonoid glycosides and terpenoid lactones (ginkgolides A, B, C and bilobalide) that inhibit platelet-activating factor and improve microcirculation. These compounds enhance nitric oxide production, reduce oxidative stress through free radical scavenging, and modulate neurotransmitter systems including acetylcholine and dopamine pathways.

Scientific Research

Multiple meta-analyses of RCTs demonstrate that Ginkgo biloba extracts, particularly EGb 761, improve cognition and daily living activities in Alzheimer's and mild dementia patients. Notable studies include PMIDs 32658034, 36960422, and 26268332.

Clinical Summary

Meta-analyses demonstrate ginkgo biloba improves cognitive function in Alzheimer's patients with a relative risk of 1.98 (95% CI 1.52-2.59, P<0.001). Studies show enhanced activities of daily living in mild dementia patients (p=0.01) and increased clinical effectiveness when combined with donepezil (RR=1.23, 95% CI 1.13-1.34). Most trials used standardized extracts containing 24% flavonoid glycosides and 6% terpenoid lactones at doses of 120-240mg daily.

Nutritional Profile

Ginkgo biloba is not a significant source of macronutrients in supplemental form (extracts). Key bioactive compounds include: Flavonoid glycosides (primarily quercetin, kaempferol, and isorhamnetin glycosides) standardized to 24% in EGb 761 extract; Terpene lactones (ginkgolides A, B, C, J and bilobalide) standardized to 6% in EGb 761 extract, with bilobalide comprising approximately 2.9% and ginkgolides approximately 3.1%; Ginkgolic acids (potentially allergenic alkylphenols, controlled to <5 ppm in pharmaceutical-grade extracts); Proanthocyanidins (~7% in standardized extracts). In whole dried leaf form: crude protein ~6-7% dry weight, crude fiber ~9-12% dry weight, crude fat ~1.5-3% dry weight, carbohydrates ~50-60% dry weight. Minerals in leaf: potassium (~9 mg/g dry weight), calcium (~8 mg/g dry weight), magnesium (~2 mg/g dry weight), iron (~0.1 mg/g dry weight), manganese (~0.07 mg/g dry weight). Ginkgo seeds (nuts) contain carbohydrates (~38g/100g), protein (~4.3g/100g), fat (~1.7g/100g), and small amounts of vitamin C (~15mg/100g) and B vitamins (thiamine ~0.22mg/100g, riboflavin ~0.09mg/100g). Bioavailability notes: Oral bioavailability of ginkgolide B is approximately 70-80%; flavonoid glycosides are hydrolyzed in the gut to aglycones before absorption, with peak plasma concentrations reached within 1.5-3 hours post-ingestion; bilobalide has a half-life of approximately 3 hours in humans. Standardized extract EGb 761 (120-240mg/day) is the most clinically studied form.

Preparation & Dosage

Clinically studied dosages for EGb 761 extract range from 120-240 mg/day over 12-52 weeks for Alzheimer's and mild dementia. Consult a healthcare provider before starting any new supplement.

Synergy & Pairings

Curcumin, Omega-3 fatty acids, Bacopa monnieri, Lion's Mane, Vitamin E

Safety & Interactions

Common side effects include headache, dizziness, gastrointestinal upset, and skin reactions in 1-2% of users. Ginkgo increases bleeding risk and should be avoided with anticoagulants like warfarin, aspirin, and clopidogrel due to platelet aggregation inhibition. Contraindicated in pregnancy and breastfeeding due to insufficient safety data. Patients should discontinue use 2 weeks before surgery due to bleeding risk.