Astringency is a well-known sensation caused by plant-derived polyphenols, such as flavanols, which are linked to reducing the risk of cardiovascular diseases. Flavanols, commonly found in cocoa, red wine, and berries, are also associated with enhancing memory, cognition, and protecting against neuronal damage. However, these benefits are hindered by the poor bioavailability of flavanols, meaning only a small fraction is absorbed into the bloodstream after ingestion.
To bridge this gap in knowledge, a team of researchers led by Dr. Yasuyuki Fujii and Professor Naomi Osakabe from Shibaura Institute of Technology in Japan delved into how flavanols impact the nervous system through sensory stimulation. Their study, published in the journal “Current Research in Food Science,” aimed to explore how the astringent taste of flavanols could serve as a direct signal to the brain.
The research team conducted experiments on 10-week-old mice, administering flavanols orally at varying doses while control mice received only water. The results showed that mice fed with flavanols exhibited increased motor activity, exploratory behavior, and enhanced learning and memory compared to the control group. The levels of neurotransmitters like dopamine and norepinephrine in the locus coeruleus–noradrenaline network were significantly elevated after flavanol administration.
Moreover, enzymes critical for noradrenaline synthesis and transport were upregulated, strengthening the signaling capacity of the noradrenergic system. Biochemical analysis revealed higher levels of stress hormones in the urine and increased activity in the hypothalamic paraventricular nucleus, a region essential for stress regulation. Overall, the study demonstrated that flavanol intake can trigger physiological responses akin to those induced by exercise, enhancing attention, arousal, and memory.
Dr. Fujii highlighted the similarity between stress responses induced by flavanols and physical exercise, suggesting that moderate flavanol intake, despite poor bioavailability, can enhance health and quality of life. These findings hold promise for the development of next-generation foods based on sensory properties, physiological effects, and palatability.
In conclusion, the study sheds light on how astringent flavanols can stimulate the central nervous system and impact neurobehavior and autonomic nerves. The implications of these findings in the realm of sensory nutrition are vast, opening doors for innovative food products that leverage the sensory properties and health benefits of flavanols.
