Ingesta dietética de flavonoides y la incidencia de Alzheimer y deterioro cognitivo en adultos: Revisión sistemática

Background: Flavonoids are antioxidants and anti-inflammatory compounds that protect neurons, enhance synaptic function, and prevent apoptosis, promoting brain health and preventing cognitive decline. The objective was to systematize the literature evaluating the association between dietary flavonoid consumption and the incidence of dementia in adults over 45 years old. Methods: A systematic review of 13 cohort studies published up to April 2022 was conducted using Embase, PubMed, Scopus, and Scielo. Studies assessing dietary flavonoid intake through validated questionnaires, with outcomes such as cognitive decline and Alzheimer's disease, were included. The studies were evaluated using the Newcastle-Ottawa scale, obtaining scores ranging from 6 to 9 points. Result: Out of 1,525 articles, 13 cohort studies were included, covering 41,229 participants aged between 45 and 98 years. The results established significant associations between high flavonoid consumption, particularly flavonols and anthocyanins, and a lower risk of cognitive decline and Alzheimer's disease in two studies with high methodological quality. However, heterogeneity in assessment methods and biases related to dietary questionnaires hindered comparability. Additionally, the lack of biomarker analysis and the inconsistent application of cognitive assessment tools may limit the validity of the findings. Conclusion: Flavonoids may have a protective effect against dementia. Future research should adopt more homogeneous designs, include biomarkers, and improve the control of confounding factors to strengthen the evidence base.