Cognition Intervention Study Dortmund- Glycemic Index (CogniDo GI)

Study Overview
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Brief Summary
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The Cognition Intervention Study Dortmund (CogniDo) and the Cognition Intervention Study Dortmund PLUS (CogniDo PLUS) investigated the short-term effects of having school lunch versus skipping it on children's basal (CogniDo) and executive (CogniDo PLUS) cognitive functions in the afternoon. The The Cognition Intervention Study Dortmund Continued (Coco) connected this two previous studies and investigates the effect of having school lunch versus skipping it on children's basal and executive cognitive functions later in the afternoon. The present study the Cognition Intervention Study Dortmund- Glycemic Index (CogniDo GI) examines the influence of the gylcemic index of lunch on cognitive performance of school children in the afternoon.

Detailed Description
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Glucose is the main fuel of the human brain. However, which impact the glycemic index of lunch has on cognitive performance is not clear. A recently published review by Philippou and Constantinou suggested cautiously that a low-GI meal may favor cognitive functions in adults, but note that their findings are inconclusive due to differences in study design, study sample (e.g. size, age), time of testing and the cognitive domain being examined. Because of cerebral particularities, children may react highly sensitive to variations of glycose supply. Therefore, an optimised composition of meals at favourable mealtime should be considered for optimal cognitive performance. The increasing implementation of all-day schools in Germany requires the children's catering for lunch at school. As prior intake of food can have an influence on the physiological effect of test meal, the children's dietary intake in the mid-morning is standardized. The intervention is integrated in everyday school life: 9.15 a.m. standardized snack within the frame of the regular break, 9.45 a.m. to 12.25 p.m. everyday school life, 12.25 p.m. lunch with a high GI-rice or a low GI-rice and a water beverage, 12.45 p.m. to 13.15 p.m. regular lunch break, 13.15 p.m. computerized tests of executive cognitive and basal (alertness) functioning. Parameters of cognition with relevance to everyday school life are measured by a computerized test program developed by the Institute of Working Learning and Aging (ALA). Usual eating behaviour, sleep behaviour, physical activity and parental education were determined as control variables by questionnaires for children, parents.

Official Title
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Cognition Intervention Study Dortmund- Glycemic Index (CogniDo GI)

Conditions
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Cognitive Function

Intervention / Treatment
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* Other: Dietary: high GI lunch
* Other: Dietary: low GI lunch


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: all fifth and sixth grade students of Gesamtschule Berger Feld with the consent of parents and child Exclusion Criteria: Metabolic diseases or special diet

Ages Eligible for Study
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Minimum Age: 10 Years
Maximum Age: 14 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Dietary: high GI lunch<br>High GI-rice lunch ad libitum on test day 1 and low GI-rice lunch on test day 2. Water at libitum was constantly available on both days. | Other: Dietary: high GI lunch<br>* High GI: High-GI rice lunch ad libitum on test day 1 and low GI-rice lunch on test day 2. Water at libitum was constantly available on both days.<br>|
| Experimental: Dietary: low GI lunch<br>Low GI-rice lunch ad libitum on test day 1 and high GI-rice lunch on test day 2. Water at libitum was constantly available on both days. | Other: Dietary: low GI lunch<br>* Low-GI: Low GI-rice lunch ad libitum on test day 1 and high GI-rice lunch on test day 2. Water at libitum was constantly available on both days.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Shifting: Change of total reaction time for a) [ms] | Measuring global task-switching costs by a three-part computer trial. a. Non-switch: digits from 1 to 26 in random order are to put in order. b. Non-switch: Same as a) with letters from A to Z c. switch: digits 1 to 13 and letters A to M in random order to put in altering ascending order (digit, letter) | participants were tested on two test days (T1 and T2) with one week wash out | 
| Shifting: Change of total reaction time for b) [ms | Measuring global task-switching costs by a three-part computer trial. a. Non-switch: digits from 1 to 26 in random order are to put in order. b. Non-switch: Same as a) with letters from A to Z c. switch: digits 1 to 13 and letters A to M in random order to put in altering ascending order (digit, letter) | participants were tested on two test days (T1 and T2) with one week wash out | 
| Shifting: Change of total switch-costs [ms | Measuring global task-switching costs by a three-part computer trial. a. Non-switch: digits from 1 to 26 in random order are to put in order. b. Non-switch: Same as a) with letters from A to Z c. switch: digits 1 to 13 and letters A to M in random order to put in altering ascending order (digit, letter) | participants were tested on two test days (T1 and T2) with one week wash out | 
| updating: change of ratio of missing [%] | Continuous monitoring and quick addition or deletion of contents within the working memory A sequence of 106 items (pictures of fruit and vegetables) is shown to the participants. A reaction is required if the actual shown item was equal to the item shown in the second to last. | participants were tested on two test days (T1 and T2) with one week wash out | 
| updating: change of ratio of false alarms [%] | Continuous monitoring and quick addition or deletion of contents within the working memory A sequence of 106 items (pictures of fruit and vegetables) is shown to the participants. A reaction is required if the actual shown item was equal to the item shown in the second to last. | participants were tested on two test days (T1 and T2) with one week wash out | 
| updating: change of mean reaction time [ms] | Continuous monitoring and quick addition or deletion of contents within the working memory A sequence of 106 items (pictures of fruit and vegetables) is shown to the participants. A reaction is required if the actual shown item was equal to the item shown in the second to last. | participants were tested on two test days (T1 and T2) with one week wash out | 
| tonic alertness: change of mean reaction time [ms] | measures the level of alertness in response to a simple visual stimulus. Mean reaction time | participants were tested on two test days (T1 and T2) with one week wash out | 
| tonic alertness: change of deviation of reaction time [ms] | measures the level of alertness in response to a simple visual stimulus. Deviation of reaction time | participants were tested on two test days (T1 and T2) with one week wash out | 
| tonic alertness:change of numbers of omission errors [n] | measures the level of alertness in response to a simple visual stimulus. subsidiary outcome is the numbers of omission errors. | participants were tested on two test days (T1 and T2) with one week wash out | 
| tonic alertness:change of numbers of commission errors [n] | measures the level of alertness in response to a simple visual stimulus. subsidiary outcome is the numbers of comission errors. | participants were tested on two test days (T1 and T2) with one week wash out | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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high GI lunch, low GI lunch