Ginkgo and Cognition

Used for thousands of years in Chinese medicine, ginkgo is also commonly recommended in Western countries for its perceived cognitive benefits. The ginkgo extracts found in dietary supplements are derived from the leaves of the Maidenhair tree (Ginkgo biloba). It contains a variety of ginkgolides (terpene lactones) and flavonoids (ginkgo flavone glycosides), which are thought to be responsible for its effects. This article will provide an overview of identified mechanisms as well as a look at the clinical evidence behind the use of Ginkgo biloba for brain health and cognition, particularly among the aging population.

Cognitive Support Through Multiple Mechanisms

As a normal part of the aging process, tissue undergoes oxidation which affects the function of multiple organs and systems in the body, including the central nervous system. In both in vitro and in vivo studies,¹ Ginkgo biloba extract (GBE) quenched free radicals and reduced oxidative stress in brain tissue commonly associated with aging.^†2,3 Antioxidant activity, however, is just one of several synergistic neurological support functions associated with Ginkgo biloba constituents. Additional mechanisms include improvement of blood flow through reduced capillary permeability;⁴ increased release of endothelial-derived relaxing factor and nitric oxide;^5,6 inhibition of beta-amyloid-derived peptides;^7,8 elevation of brain-derived neurotrophic factor (BDNF) levels;⁹ enhancement of synaptic plasticity associated with memory and spatial learning;¹⁰ and balance of normal neurotransmission, including serotonin and dopamine.^†11 It is of further interest that beneficial activity of ginkgo is not limited to a protective role alone. Although isolated bilobalide has been shown to inhibit neuronal apoptosis,¹² an independent molecular docking study also demonstrated that quercetin, an active constituent of ginkgo, was a potent inducer of aberrant cell cycle arrest and apoptosis.^†13

The Potential for Humans

Well over 250 clinical trials have been published on Ginkgo biloba, with predominantly positive results. It has been studied for cognitive health and brain aging, cerebrovascular and peripheral vascular health and circulation, bronchial health, altitude acclimation, hearing issues, vision, colorectal health, cell cycle regulation, sexual function, and mood support, among other indications.^†

Results showed supplementation with a Ginkgo biloba extract supported improved cognitive function...

In 2013, Amieva and colleagues published a 20-year follow-up population-based study¹⁴ of more than 3,500 normal individuals over the age of 65 at baseline. Findings indicated a support of cognitive function in the Ginkgo biloba group compared to those taking Piracetam, or no supplementation at all.^† Other studies have looked at the potential of Ginkgo biloba to support healthy cognitive function in aging individuals. In one such 2011 randomized controlled trial, results showed supplementation with a Ginkgo biloba extract supported improved cognitive function and quality of life scores compared with placebo.^†15

Although further study is clearly needed, the safety and existing evidence for Ginkgo biloba extract appears to support routine supplementation in healthy aging.^†1,16,17