Flavanol's astringency affects brain + body https://www.sciencedirect.com/science/article/pii/S2665927125002266 Astringency is a dry, puckering sensation in the mouth caused by plant-derived polyphenols. Polyphenols, including flavanols, are well known for risk reduction in cardiovascular diseases https://medicalxpress.com/news/2025-10-astringent-sharper-mind-flavanols-trigger.html