Plant-derived nootropics and human cognition: A systematic review

Summary & key facts

This systematic review examined human studies of plant-derived nootropics across six cognitive domains. It included 256 papers published from January 2000 to November 2021 found via PubMed, Cochrane and Scopus. The review reports that Ginkgo biloba was most relevant for perceptual and motor functions, Bacopa monnieri improved language, learning and memory, Withania somnifera (Ashwagandha) modulated anxiety and social-related cognition, and caffeine enhanced attention and executive functions. The authors note that results are inconsistent across studies and more research is needed.

Key facts:

• The review included 256 human studies and systematic reviews published between January 2000 and November 2021.
• Researchers performed six independent searches, one for each neurocognitive domain, using three databases: PubMed, Cochrane and Scopus.
• Ginkgo biloba was identified by the review as the most relevant plant-derived nootropic for perceptual and motor functions.
• Bacopa monnieri was reported to improve language, learning, and memory in the compiled studies.
• Withania somnifera (Ashwagandha) was reported to modulate anxiety and social-related cognitive functions.
• Caffeine was reported to enhance attention and executive functions.
• The authors state that the compiled studies show both nootropic effects and inconsistencies in findings.
• The review concludes that further research is required to clarify and confirm the effects of plant-derived nootropics.

Abstract

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.

Topics

Medicinal Plants and Neuroprotection Neuroinflammation and Neurodegeneration Mechanisms Olfactory and Sensory Function Studies

Categories

Complementary and alternative medicine Health Sciences Medicine

Tags

Biochemistry Biology Cognition Ginkgo biloba Medicine MEDLINE Neurocognitive Nootropic Pharmacology Psychiatry Psychology Scopus Systematic review Traditional medicine