Gingko (Gingko biloba) is a very ancient tree species with an evolutionary line going back 200 million years. An extract from its leaves has been used as a tonic in alternative medicines to generate a number of health benefits including mental and cognitive health in particular, blood and heart health and its antioxidant properties. Recently, EFSA did not consider the evidence for its antioxidant properties good enough for an Article 13 ruling but the evidence continues to build for its efficacy in other areas.

One property the Gingko extract possesses is increasing cerebral blood flow and modifying the biochemistry of  brain based neurotransmitters.  Numerous studies were performed to assess various effects on mood, however many report no effect whatsoever so there are mixed results.  Those studies that did report effects suggested ginkgo could improve mood, alertness and calmness.  In an early study, participants receiving 120mg of ginkgo biloba extract per day reported feeling better able to cope with daily living and had reduced anxiety and depression (Cockle et al., 2000). Later, in a self-reporting study, treatment with 120mg/day ginkgo for four weeks improved the quality of life and increased the positive mood state in healthy older individuals compared to a placebo (Cleza et al., 2003). Ginkgo has also been reported to improve alertness and contentedness (Kennedy et al., 2002).

Mood is often assessed in these studies using self-reported questionnaires, POMS (profile of mood states)  and the Bond-Lader VAS (visual analogue scales). However numerous studies showed no effect on mood in healthy participants, both in young and older individuals ranging from 1 hour post ingestion, to  6 hours post-dose of up to 6 weeks later. In a critique, Gorby et al., (2010) concluded that no definitive conclusions could be made regarding ginkgo and mood due to poor study designs and inconsistent findings.

References

Cieza, A. Maier, P. Poppel, E. (2003) Effects of Ginkgo biloba on mental functioning in healthy volunteers. Arch Med Res 34 pp.373-81

Cockle, S.M. Kimber, S. Hindmarch, I. (2000) The effects of Ginkgo biloba extract (LI 1370) supplementation on activities of daily living in free living older volunteers: a questionnaire survey. Human Psychopharmacology 15 pp. 227-35

Gorby, H.E. Brownawell, A.M. Falk, M.C. (2010) Do specific dietary constituents and supplements affect mental energy? Review of the evidence. Nutrition Reviews 68 (12) pp.697-718