Rosander Ulla, Rumpunen Kimmo, Olsson Viktoria, Åström Mikael, Rosander Pia, Wendin Karin
School of Education and Environment, Kristianstad University, Kristianstad, Sweden.
Department of Plant Breeding, Swedish University of Agricultural Sciences, Balsgård, Sweden.
Food Nutr Res. 2017 Nov 30;61(1):1409063. doi: 10.1080/16546628.2017.1409063. eCollection 2017.
Berries contain bioactive compounds that may affect children's cognitive function positively, while hunger and thirst during lessons before lunch affect academic performance negatively. This pilot study addresses methodological challenges in studying if a berry smoothie, offered to schoolchildren as a mid-morning beverage, affects academic performance. The objective was to investigate if a cross-over design can be used to study these effects in a school setting. Therefore, in order to investigate assay sensitivity, 236 Swedish children aged 10-12 years were administered either a berry smoothie (active) or a fruit-based control beverage after their mid-morning break. Both beverages provided 5% of child daily energy intake. In total, 91% of participants completed the study. Academic performance was assessed using the d2 test of attention. Statistical analyses were performed using the Wilcoxon signed rank test in StatXact v 10.3. The results showed that the children consumed less of the active berry smoothie than the control (154 g vs. 246 g). Both beverages increased attention span and concentration significantly (p = 0.000). However, as there was no significant difference (p = 0.938) in the magnitude of this effect between the active and control beverages, the assay sensitivity of the study design was not proven. The effect of the beverages on academic performance was attributed the supplementation of water and energy. Despite careful design, the active smoothie was less accepted than the control. This could be explained by un-familiar sensory characteristics and peer influence, stressing the importance of sensory similarity and challenges to perform a study in school settings. The employed cross-over design did not reveal any effects of bioactive compound consumption on academic performance. In future studies, the experimental set up should be modified or replaced by e.g. the parallel study design, in order to provide conclusive results.
浆果含有可能对儿童认知功能产生积极影响的生物活性化合物，而午餐前上课期间的饥饿和口渴则会对学业成绩产生负面影响。这项初步研究解决了在研究向学童提供的浆果奶昔作为上午课间饮料是否会影响学业成绩时所面临的方法学挑战。目的是调查交叉设计是否可用于在学校环境中研究这些影响。因此，为了调查测定灵敏度，在上午课间休息后，给236名10至12岁的瑞典儿童饮用了一杯浆果奶昔（实验组）或一种以水果为基础的对照饮料。两种饮料均提供儿童每日能量摄入量的5%。总共有91%的参与者完成了研究。使用注意力d2测试评估学业成绩。使用StatXact v 10.3中的Wilcoxon符号秩检验进行统计分析。结果表明，儿童饮用的实验组浆果奶昔比对照组少（154克对246克）。两种饮料均显著提高了注意力持续时间和注意力集中度（p = 0.000）。然而，由于实验组和对照组饮料在这种效果的程度上没有显著差异（p = 0.938），因此该研究设计的测定灵敏度未得到证实。饮料对学业成绩的影响归因于水和能量的补充。尽管设计精心，但实验组奶昔比对照组更不被接受。这可以用不熟悉的感官特征和同伴影响来解释，强调了感官相似性的重要性以及在学校环境中进行研究的挑战。所采用的交叉设计未显示生物活性化合物摄入对学业成绩有任何影响。在未来的研究中，应修改实验设置或用例如平行研究设计取代，以便得出确凿的结果。
