Cognitive Effects of Drinking Water and Improving Hydration Status Among Schoolchildren

There is a large body of evidence from adult populations suggesting cognition in adults is affected by hydration status. The few studies conducted in the global North in populations of schoolchildren indicate that drinking water has an impact on pupil performance on basic cognitive tasks. No studies assessing the impact of dehydration and cognition in schoolchildren have been carried out in the global South, where access to water is the poorest and dehydration prevalence is likely higher. This study will examine the effect of drinking supplementary water during the school day on hydration status and on cognitive test scores in schoolchildren in Mali, West Africa.

The investigators hypothesize that providing supplemental water will result in a decrease in prevalence of dehydration in the study group and will result in an improved performance on cognitive test scores.

Data will be collected from up to four purposively-selected schools in the Sikasso region of Mali, from up to a total of 300 children. At each school pupils in grades 3-6 will be eligible for recruitment. Research staff will explain the study to pupils at the school and individually request informed oral assent for participation. A waiver of parental consent for pupil interviews will be secured from the Ministry of Education. At each school, school directors will be asked to sign in loco parentis ("in the place of parent") on behalf of the pupil participants.

Children that assent to participate in the study will be randomly allocated to the intervention or control group. Data collection will take place at each school over two days within a one-week period, with one study group tested on each of the two days. On the intervention testing day, all study participants will receive supplementary water. On the control testing day, no study participants will receive supplementary water. Testing procedures in both groups is identical and will include a five-minute interview, two cognitive testing sessions of 45 minutes each, and collection of two urine samples during the day. None of these activities collect personal data or identifiers, and the urine sample will not be stored.

All data collection will occur at the school and will be conducted by trained local enumerators. There are no risks to participation other than a small amount of class time missed by pupils, and great efforts will be made to minimize time outside of class.