![Sample our Medicine, Dentistry, Nursing & Allied Health journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/5944/TOC-Subject-Sample-2021-Medicine-Dentistry-Nursing-Allied-Health.jpg"})
Abstract
The limited literature on the effects of dehydration on human cognitive function is contradictory and inconsistent. Although it has been suggested that decrements in cognitive performance are present in the range of a 2 to 3% reduction in body weight, several dose-response studies indicate dehydration levels of 1% may adversely affect cognitive performance. When a 2% or more reduction in body weight is induced by heat and exercise exposure, decrements in visual-motor tracking, short-term memory and attention are reported, but not all studies find behavioral effects in this range. Future research should be conducted using dose-response designs and state-of-the-art behavioral methods to determine the lowest levels of dehydration that produce substantive effects on cognitive performance and mood. Confounding factors, such as caffeine intake and the methods used to produce dehydration, need to be considered in the design and conduct of such studies. Inclusion of a positive control condition, such as alcohol intake, a hypnotic drug, or other treatments known to produce adverse changes in cognitive performance should be included in such studies. To the extent possible, efforts to blind both volunteers and investigators should be an important consideration in study design.
Key teaching points:
• Dehydration impairs cognitive performance and mood.
• Adverse effects of dehydration on cognitive function are present at a 2% or more reduction in hydration and may be present at a 1% level of dehydration.
• Most studies of the effects of dehydration on cognitive function have used heat and exercise to induce rapid dehydration.
• Studies of the effect of dehydration on cognitive function should employ dose-response designs.
• The specific behavioral functions most likely to be affected by dehydration have not been established; additional studies should be conducted using state-of-the-art performance tests and mood questionnaires.
• Double-blind procedures, or surrogates for these procedures, should be employed whenever possible in studies of cognitive function and dehydration.
Key teaching points:
• Dehydration impairs cognitive performance and mood.
• Adverse effects of dehydration on cognitive function are present at a 2% or more reduction in hydration and may be present at a 1% level of dehydration.
• Most studies of the effects of dehydration on cognitive function have used heat and exercise to induce rapid dehydration.
• Studies of the effect of dehydration on cognitive function should employ dose-response designs.
• The specific behavioral functions most likely to be affected by dehydration have not been established; additional studies should be conducted using state-of-the-art performance tests and mood questionnaires.
• Double-blind procedures, or surrogates for these procedures, should be employed whenever possible in studies of cognitive function and dehydration.
This work was supported by the U.S. Army Medical Research and Materiel Command (USAMRMC). The views, opinions, and/or findings in this report are those of the authors, and should not be construed as an official Department of the Army position, policy, or decision, unless so designated by other official documentation. Citation of commercial organization and trade names in this report do not constitute an official Department of the Army endorsement or approval of the products or services of these organizations.
Notes
Conflict of Interest Disclosure: There are no conflicts of interest to declare in connection with this work.
Presented at the ILSI North America 2006 Conference on Hydration and Health Promotion, November 29–30, 2006 in Washington, DC.
