Philippou Elena, Constantinou Marios
Department of Life and Health Sciences, School of Sciences and Engineering, and.
Adv Nutr. 2014 Mar 1;5(2):119-30. doi: 10.3945/an.113.004960.
The impact of the rate of carbohydrate absorption, as measured by the carbohydrate's glycemic index (GI) on cognitive performance, is not clear. The aim of this review was to systematically assess the relevant research studies. A systematic review of English-language articles using Medline, Cochrane Central Register of Controlled Trials, EMBASE, PsycINFO, and PsycARTICLES (up to July 2012) using the search terms "glyc(a)emic index" or "glycaemic load" combined with "cognitive function" or "cognition" or "memory" was carried out. Inclusion and exclusion criteria were prespecified. Eligibility of the identified studies was assessed independently by the 2 reviewers. Independent extraction of data was carried out by the 2 authors using predefined data fields. The primary outcome measure was the effect on cognitive function (CF) after the consumption of meals varying in GI. Eleven eligible studies were identified. The age range of the participants varied from 6 to 82 y old. Overall, the findings were inconsistent, with some studies showing benefits toward either the high-GI or the low-GI meal, others not finding any differences between the 2 meals, and other studies showing a positive or negative effect on performance on only some cognitive domain or domains after consumption of 1 of the 2 meals. A number of methodologic and confounding factors were identified that could explain these inconsistencies. These include the study design, the selected sample (size, age, blood glucose regulation), the timing of testing, the cognitive domain being examined, the number and type of cognitive tests used, the meals provided (composition, size), the timing of blood samples collected, as well as the possibility of bias because participants and investigators were not blinded to randomization. A low-GI meal may favor CF in adults, but the findings at present are inconclusive. On the basis of this review, it is suggested that future studies address the identified methodologic issues and some recommendations are proposed to this effect.
通过碳水化合物血糖生成指数（GI）衡量的碳水化合物吸收速率对认知表现的影响尚不清楚。本综述的目的是系统评估相关研究。使用检索词“血糖（a）生成指数”或“血糖负荷”与“认知功能”或“认知”或“记忆”相结合，对Medline、Cochrane对照试验中央注册库、EMBASE、PsycINFO和PsycARTICLES（截至2012年7月）中的英文文章进行系统综述。预先设定了纳入和排除标准。由两名评审员独立评估所识别研究的合格性。两名作者使用预定义的数据字段独立进行数据提取。主要结局指标是食用不同GI的餐食后对认知功能（CF）的影响。共识别出11项合格研究。参与者的年龄范围为6至82岁。总体而言，研究结果不一致，一些研究表明高GI或低GI餐食有有益作用，其他研究未发现两种餐食之间有任何差异，还有一些研究表明食用两种餐食中的一种后仅对某些认知领域的表现有正面或负面影响。确定了一些方法学和混杂因素可以解释这些不一致性。这些因素包括研究设计、所选样本（大小、年龄、血糖调节）、测试时间、所检查的认知领域、所使用的认知测试的数量和类型、提供的餐食（成分、大小）、采集血样的时间，以及由于参与者和研究者未对随机分组进行盲法而可能产生的偏倚。低GI餐食可能对成年人的CF有益，但目前的研究结果尚无定论。基于本综述，建议未来的研究解决已识别的方法学问题，并为此提出了一些建议。
