The Effect of Small Changes in Hydration on Cognition

Not Applicable

Completed

• Conditions: Cognition; Hydration
• Interventions: Dietary Supplement: Water

• Registration Number: NCT02671149
• Lead Sponsor: Swansea University

Brief Summary

The aim of this study is to determine whether drinking plain water when mildly dehydrated benefits cognitive performance and mood. Volunteers undergo a dehydration protocol designed to result in minor dehydration. While some participants receive two 150ml drinks of water others do not. Differences in cognitive functioning are assessed.

Detailed Description

As an essential nutrient, an inadequate intake of water has negative consequences: without a source of water death will occur in days. When Benton and Young (2015) reviewed the topic they concluded that in healthy adults, mild dehydration (in the range of a loss of 2% body mass) had been found to adversely influence mood and cognition. However, it is unclear at what degree of hypohydration these effects begin to emerge.

This study was designed to determine whether small changes in hydration, of the level that might occur on a day to day basis, influence cognition and mood. During a dehydration protocol (sitting in a room heated to 30 degrees for four hours) young adult participants receive either drink two 150ml cups of water or nothing. Effects on memory, attention and mood are monitored.

Study Timeline

• Study Start: 2015-09
• Study First Submitted: 2015-09-22
• Study First Submitted QC: 2016-02-01
• Study First Posted: 2016-02-02
• Primary Completion: 2016-03
• Study Completion: 2016-03
• Status Verified: 2020-04
• Last Update Submitted: 2020-04-03
• Last Update Posted: 2020-04-06

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 101

Inclusion Criteria

• In good general health i.e. no major health condition such as diabetes
• BMI < 30

Exclusion Criteria

• Not on blood pressure medication or blood thinning medication such as aspirin - No learning difficulty such as dyslexia
• Diabetes
• Gastro-intestinal disease
• High BMI
• Cholesterol and BP
• Smoker
• Dyslexic/dyspraxic
• Depression or history of depression or other psychiatric disorder

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Drink water	Water	Participants will receive two 150ml drinks of water during the dehydration protocol

Primary Outcome Measures

Name	Time	Method
Focused attention - Eriksen Flanker Task	change from 0 to 180 minutes after the start of the dehydration protocol	The Arrow Flankers test measures the ability to direct attention and ignore peripheral information. Participants are required to indicate whether the middle arrow is pointing to the right or left by pressing the corresponding arrow on the keyboard. Either side of the central arrow are distractors. Both the average reaction times (in milliseconds) and accuracy are recorded. The difference in performance from baseline (before the intervention) is analysed.
Episodic memory - list of 30 words	change from 0 to 180 minutes after the start of the dehydration protocol	Participants listen to a list of 30 words presented using a tape recorder. The words are of similar difficulty and matched for the number of syllables and frequency with which they occur in English. The subjects are asked to recall and write down as many words as possible. The difference in the total number of words remembered from baseline (before the intervention) is analysed.

Secondary Outcome Measures

Name	Time	Method
Thirst (Participants rate their thirst)	change from 0 to 180 minutes after the start of the dehydration protocol	Participants rate their thirst

Trial Locations

Locations (1)

Swansea University; 🇬🇧 Swansea, West Glamorgan, United Kingdom