Institute of Sport Sciences, Otto-von-Guericke University, 39104 Magdeburg, Germany.
High Institute of Sport and Physical Education, University of Sfax, Sfax 3000, Tunisia.
Nutrients. 2020 Sep 19;12(9):2872. doi: 10.3390/nu12092872.
Recent anti-aging interventions have shown contradictory impacts of (poly)phenols regarding the prevention of cognitive decline and maintenance of brain function. These discrepancies have been linked to between-study differences in supplementation protocols. This subgroup analysis and meta-regression aimed to (i) examine differential effects of moderator variables related to participant characteristics and supplementation protocols and (ii) identify practical recommendations to design effective (poly)phenol supplementation protocols for future anti-aging interventions.
Multiple electronic databases (Web of Science; PubMed) searched for relevant intervention published from inception to July 2019. Using the PICOS criteria, a total of 4303 records were screened. Only high-quality studies ( = 15) were included in the final analyses. Random-effects meta-analysis was used, and we calculated standard differences in means (SDM), effect size (ES), and 95% confidence intervals (CI) for two sufficiently comparable items (i.e., psychomotor function and brain-derived neurotrophic factor (BDNF)). When significant heterogeneity was computed ( > 50%), a subgroup and meta-regression analysis were performed to examine the moderation effects of participant characteristics and supplementation protocols.
The reviewed studies support the beneficial effect of (poly)phenols-rich supplementation on psychomotor functions (ES = -0.677, = 0.001) and brain plasticity (ES = 1.168, = 0.028). Subgroup analysis revealed higher beneficial impacts of (poly)phenols (i) in younger populations compared to older (SDM = -0.89 vs. -0.47 for psychomotor performance, and 2.41 vs. 0.07 for BDNF, respectively), (ii) following an acute compared to chronic supplementation (SDM = -1.02 vs. -0.43 for psychomotor performance), and (iii) using a phenolic compound with medium compared to low bioavailability rates (SDM = -0.76 vs. -0.68 for psychomotor performance and 3.57 vs. 0.07 for DBNF, respectively). Meta-regressions revealed greater improvement in BDNF levels with lower percentages of female participants (Q = 40.15, df = 6, < 0.001) and a skewed scatter plot toward a greater impact using higher (poly)phenols doses.
This review suggests that age group, gender, the used phenolic compounds, their human bioavailability rate, and the supplementation dose as the primary moderator variables relating to the beneficial effects of (poly)phenol consumption on cognitive and brain function in humans. Therefore, it seems more advantageous to start anti-aging (poly)phenol interventions in adults earlier in life using medium (≈500 mg) to high doses (≈1000 mg) of phenolic compounds, with at least medium bioavailability rate (≥9%).
最近的抗衰老干预措施表明，（多）酚类物质在预防认知能力下降和维持大脑功能方面的作用存在矛盾。这些差异与研究之间补充方案的差异有关。本亚组分析和荟萃回归旨在：（i）研究与参与者特征和补充方案相关的调节变量的差异影响；（ii）确定设计有效的（多）酚类物质抗衰老干预补充方案的实用建议。
通过多个电子数据库（Web of Science；PubMed）检索从成立到 2019 年 7 月的相关干预措施。使用 PICOS 标准，共筛选了 4303 份记录。只有高质量的研究（= 15）被纳入最终分析。采用随机效应荟萃分析，我们计算了两个足够可比项目（即精神运动功能和脑源性神经营养因子（BDNF））的标准均值差异（SDM）、效应量（ES）和 95%置信区间（CI）。当计算出显著的异质性（> 50%）时，进行亚组和荟萃回归分析，以研究参与者特征和补充方案的调节作用。
综述研究支持富含（多）酚的补充对精神运动功能（ES = -0.677， = 0.001）和大脑可塑性（ES = 1.168， = 0.028）有益。亚组分析显示，（多）酚的有益影响在以下情况下更高：（i）与老年人相比，年轻人（精神运动表现的 SDM = -0.89 与 -0.47，BDNF 的 SDM = 2.41 与 0.07）；（ii）与慢性补充相比，急性补充（精神运动表现的 SDM = -1.02 与 -0.43，BDNF 的 SDM = -0.76 与 -0.68）；（iii）使用具有中等到低生物利用度的酚类化合物（精神运动表现的 SDM = -0.76 与 -0.68，BDNF 的 SDM = 3.57 与 0.07）。荟萃回归显示，BDNF 水平的改善与女性参与者的比例较低（Q = 40.15，df = 6， < 0.001）以及使用较高（多）酚剂量时的散点图偏向更大影响有关。
本综述表明，年龄组、性别、使用的酚类化合物、其人体生物利用度以及补充剂量是与（多）酚类物质对人类认知和大脑功能的有益影响相关的主要调节变量。因此，似乎更有利的是，在生命早期，使用具有中等到高剂量（≈500mg 至≈1000mg）、至少具有中等到高生物利用度（≥9%）的酚类化合物，在成年人中更早开始抗衰老（多）酚类物质干预。
