Hydration and cognition: a critical review and recommendations for future research.
- Harris R Lieberman
- Journal of the American College of Nutrition
Introduction There is limited literature on the effects of a deficit in body water on human cognitive function, with inconsistent and contradictory results. In his critical review of this area Lieberman  recommended that typical confounding factors such as the method to induce dehydration (exercise, heat stress, diuretics) and other experimental control (sleep, diet, caffeine) should be considered carefully as little existing research has done so. Few studies have actually assessed what occurs naturally, namely a person simply not drinking sufficiently. The purpose of this study was to measure the cognitive effects of ‘not drinking enough’ (’voluntary dehydration’) when other confounding factors such as sleep, diet and caffeine are controlled.