Multiple n = 1 trials in the identification of responders and non-responders to the cognitive effects of Ginkgo biloba

Plant-derived nootropics and human cognition: A systematic review

Substances with modulatory capabilities on certain aspects of human cognition have been revered as nootropics from the dawn of time. The plant kingdom provides most of the currently available nootropics of natural origin. Here, in this systematic review, we aim to provide state-of-the-art information regarding proven and unproven effects of plant-derived nootropics (PDNs) on human cognition in conditions of health and disease. Six independent searches, one for each neurocognitive domain (NCD), were performed in parallel using three independent scientific library databases: PubMed, Cochrane and Scopus. Only scientific studies and systematic reviews with humans published between January 2000 and November 2021 were reviewed, and 256 papers were included. Ginkgo biloba was the most relevant nootropic regarding perceptual and motor functions. Bacopa monnieri improves language, learning and memory. Withania somnifera (Ashwagandha) modulates anxiety and social-related cognitions. Caffeine enhances attention and executive functions. Together, the results from the compiled studies highlight the nootropic effects and the inconsistencies regarding PDNs that require further research.Supplemental data for this article is available online at https://doi.org/10.1080/10408398.2021.2021137.

The effect of Ginkgo biloba on functional measures in multiple sclerosis: a pilot randomized controlled trial

BACKGROUND

Multiple sclerosis (MS) is a chronic demyelinating neurological disease afflicting young and middle-aged adults, resulting in problems with coordination, strength, cognition, affect, and sensation.

OBJECTIVE

The objective of this study was to determine whether a ginkgo extract (EGb 761) improved functional performance in individuals with MS.

DESIGN

This study used a double-blind, placebo-controlled, parallel group design. The end point was change between baseline (ie, preintervention) and follow-up evaluation following a regimen of four tablets per day at 60 mg per tablet for four weeks.

SETTING

The study was conducted in academic and clinical-based settings.

PATIENTS/PARTICIPANTS

Twenty-two individuals with MS were randomly assigned to either the treatment or control condition. Groups did not differ with respect to age, IQ, and education.

INTERVENTION

Half of the subjects received 240 mg per day of ginkgo special extract (EGb 761), and the other half received placebo.

MAIN OUTCOME MEASURE

The main outcome measures assessed depression (Center for Epidemiologic Studies of Depression Scale [CES-D]), anxiety (State-Trait Anxiety Inventory [STAI]), fatigue (Modified Fatigue Impact Scale [MFIS]); symptom severity (Symptom Inventory [SI]) and functional performance (Functional Assessment of Multiple Sclerosis [FAMS]).

RESULTS

The ginkgo group had significantly more individuals showing improvement on four or more measures with improvements associated with significantly larger effect sizes on measures of fatigue, symptom severity, and functionality. The ginkgo group also exhibited less fatigue at follow-up compared with the placebo group.

CONCLUSIONS

This exploratory pilot study showed that no adverse events or side effects were reported and that ginkgo exerted modest beneficial effects on select functional measures (eg, fatigue) among some individuals with MS.