"Do polyphenols enter the brain and does it matter? Some theoretical and practical considerations" - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3316747/ https

"Do polyphenols enter the brain and does it matter? Some theoretical and practical considerations" - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3316747/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3316747/ >In this paper, we summarize published data on the penetration of PPs into animal brain and review some hypotheses to explain the biological basis of potentially health-beneficial effects of PPs to the brain. Finally, we highlight promising new approaches, especially those of a hormetic dose-response and gut microbiota-brain interaction, which may allow a better understanding of PPs’ mode of action in animals and humans. Only in very low concentrations, but there might be enough for an effect. Possible mechanisms are not well understood.