Effects of Ginkgo biloba on alertness and chemosensory function in healthy adults

Ginkgo biloba is reported to enhance cognitive function in patients with selected neural disorders. Its effects in healthy, young adults are less well characterized. This work explored whether Ginkgo biloba could ameliorate decrements in alertness post-prandially and/or enhance chemosensory function. Both are functions that could be influenced by enhanced cerebral blood flow and neuronal metabolism, reported properties of the compound. A double-blind placebo-controlled study was conducted with 19 males and 20 females with a mean age of 23.6 +/- 5.4 years and mean weight of 70.0 +/- 1.9 kg. Participants were supplemented for 13 weeks with either Ginkgo biloba (mean dose 184.5 mg/d (range 130-234 mg/d)) or placebo and administered various alertness, performance, affective state and chemosensory tests at weeks 1, 5, 9 and 13. Participants did experience the post-prandial affective state decrement (i.e. post-lunch dip), but not the performance decrement. Performance on the chemosensory tests improved over the 13-week study. However, Ginkgo biloba was ineffective at alleviating the symptoms of the post-lunch dip or at enhancing taste and smell function.