Plant-derived nootropics and human cognition: A systematic review

Summary & key facts

Researchers collected and checked human studies from 2000 to 2021 to see which plant-based substances can help thinking and brain skills. They combined results from six areas of cognition and included about 250 studies. Some plants showed specific benefits: ginkgo was most linked to perception and motor skills, bacopa to learning and memory and language, and ashwagandha to anxiety and social thinking. Caffeine was linked to better attention and planning. However, the results were not the same across all studies. The authors say the evidence is promising but mixed, and more careful human research is needed before we can be sure these plants help most people.

Key facts:

• The review looked only at human studies published between 2000 and 2021 and included about 256 papers across six brain-skill areas.
• Ginkgo biloba was the most often linked plant to better perceptual and motor functions, such as visual processing and coordination.
• Bacopa monnieri was reported in multiple studies to help language, learning, and memory in people.
• Withania somnifera, also known as ashwagandha, was reported to change anxiety and some social thinking skills in people.
• Caffeine was repeatedly associated with improved attention and some planning and decision-making skills.
• The authors found inconsistent results across studies, meaning that benefits were not seen in every test or every group of people.
• The review excluded animal experiments and focused only on what was shown in human research.
• Because studies used different doses, different tests, and different groups of people, the authors say more high-quality human studies are needed before strong conclusions can be made.

Abstract

(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

Substances

Other

Conditions & symptoms

Anxiety Anxiety or worry Difficulty focusing