Lamport Daniel Joseph, Williams Claire Michelle
School of Psychology and Clinical Language Science, University of Reading, Reading, RG66AL, UK.
Brain Plast. 2021 Feb 9;6(2):139-153. doi: 10.3233/BPL-200111.
There is increasing interest in the impact of dietary influences on the brain throughout the lifespan, ranging from improving cognitive development in children through to attenuating ageing related cognitive decline and reducing risk of neurodegenerative diseases. Polyphenols, phytochemicals naturally present in a host of fruits, vegetables, tea, cocoa and other foods, have received particular attention in this regard, and there is now a substantial body of evidence from experimental and epidemiological studies examining whether their consumption is associated with cognitive benefits.
The purpose of this overview is to synthesise and evaluate the best available evidence from two sources, namely meta-analyses and systematic reviews, in order to give an accurate reflection of the current evidence base for an association between polyphenols and cognitive benefits.
Four meta-analyses and thirteen systematic reviews published between 2017-2020 were included, and were categorised according to whether they reviewed specific polyphenol-rich foods and classes or all polyphenols. A requirement for inclusion was assessment of a behavioural cognitive outcome in humans.
A clear and consistent theme emerged that whilst there is support for an association between polyphenol consumption and cognitive benefits, this conclusion is tentative, and by no means definitive. Considerable methodological heterogeneity was repeatedly highlighted as problematic such that the current evidence base does not support reliable conclusions relating to efficacy of specific doses, duration of treatment, or sensitivity in specific populations or certain cognitive domains. The complexity of multiple interactions between a range of direct and indirect mechanisms of action is discussed.
Further research is required to strengthen the reliability of the evidence base.
饮食对大脑在整个生命周期中的影响越来越受到关注，从促进儿童认知发展到减轻与衰老相关的认知衰退以及降低神经退行性疾病的风险。多酚是一类天然存在于许多水果、蔬菜、茶、可可和其他食物中的植物化学物质，在这方面受到了特别关注，现在有大量来自实验和流行病学研究的证据，探讨食用多酚是否与认知益处相关。
本综述的目的是综合和评估来自荟萃分析和系统评价这两个来源的最佳现有证据，以便准确反映目前关于多酚与认知益处之间关联的证据基础。
纳入了2017年至2020年期间发表的四项荟萃分析和十三项系统评价，并根据它们是否回顾了特定富含多酚的食物和类别或所有多酚进行分类。纳入的一个要求是评估人类的行为认知结果。
出现了一个明确且一致的主题，即虽然支持多酚消费与认知益处之间的关联，但这一结论是初步的，绝不是确定的。相当大的方法学异质性被反复强调是有问题的，以至于目前的证据基础不支持关于特定剂量、治疗持续时间或特定人群或某些认知领域敏感性的可靠结论。讨论了一系列直接和间接作用机制之间复杂的多重相互作用。
需要进一步研究以加强证据基础的可靠性。
