Dehydration and cognition: an understated relation

Water is essential for mental health. In spite of research evidence that dehydration has detrimental effects on cognitive functioning, the element of water has often been understated in the nutrition literature. The purpose of this paper is to highlight the necessity to integrate water as an essential nutrient for healthy cognitive functioning in nutrition research.

This study is based on a general review. The first section reviews the literature on the relationship between dehydration and cognitive performance in both adult and children populations, using electronic databases for systematic reviews and meta-analyses (excluding vulnerable populations, such as infants, the elderly and people with disabilities). The second section examines the status of water, as a nutrient, in nutrition and water-related documentation by international authorities (FAO, UNICEF, World Food Program, WHO, etc.).

Dehydration, even at mild levels, is associated with impairments in basic and higher order cognitive functions. Websites from international authoritative nutrition sources understate the role of water in healthy nutrition, and omit the discussion of the impact of dehydration on cognitive functioning.

The relation between dehydration and cognition is under-documented and not enough elaborated in guidelines and texts of authoritative international health policy and dietary sources.