LePing Li, Henry H Y Tong
Cocoa polyphenols have emerged as promising nutritional modulators of cerebral health through their multifaceted effects on neurobiological pathways. This review synthesizes contemporary clinical and preclinical evidence regarding their implications in depression, the gut-brain axis, neuroplasticity, and cognitive function across various neurological disorders and healthspan. Evidence derived from randomized controlled trials indicates that cocoa consumption may mitigate depressive symptoms and enhance mood states, potentially via the modulation of dopaminergic activity and emotional processing. Concurrently, cocoa polyphenols display prebiotic-like characteristics, altering the composition and diversity of gut microbiota, which may facilitate improvements in negative affect through the gut-brain axis. Nevertheless, the evidence pertaining to cognitive outcomes remains markedly inconsistent. While investigations utilizing animal models reliably indicate enhancements in spatial memory, hippocampal synaptic plasticity, neurogenesis, and equilibrium in oxidative stress, extensive human clinical trials yield either minimal or no substantial advantages in global cognitive function. Certain advancements are noted within specific areas, including executive function, alleviation of fatigue, and performance on tasks during stress-inducing scenarios. Mechanistically, cocoa polyphenols exhibit neuroprotective properties via the activation of Brain-derived neurotrophic factor/cAMP-response element binding protein signaling pathways, augmentation of cerebral blood circulation, antioxidant and anti-inflammatory effects, as well as the modulation of mitochondrial and apoptotic mechanisms. In summary, cocoa polyphenols present a potentially effective dietary approach for fostering brain health, particularly concerning mood regulation and neuroplasticity; however, additional rigorously designed research is essential to elucidate their cognitive effectiveness and clinical significance.