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The Effect of Small Changes in Hydration on Cognition

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT02671149
Recruitment Status : Completed
First Posted : February 2, 2016
Last Update Posted : April 6, 2020
Information provided by (Responsible Party):
Dr Hayley Young, Swansea University

Tracking Information
First Submitted Date  ICMJE September 22, 2015
First Posted Date  ICMJE February 2, 2016
Last Update Posted Date April 6, 2020
Actual Study Start Date  ICMJE September 2015
Actual Primary Completion Date March 2016   (Final data collection date for primary outcome measure)
Current Primary Outcome Measures  ICMJE
 (submitted: February 1, 2016)
  • Episodic memory - list of 30 words [ Time Frame: 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.
  • Focused attention - Eriksen Flanker Task [ Time Frame: 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.
Original Primary Outcome Measures  ICMJE Same as current
Change History
Current Secondary Outcome Measures  ICMJE
 (submitted: February 1, 2016)
Thirst (Participants rate their thirst) [ Time Frame: change from 0 to 180 minutes after the start of the dehydration protocol ]
Participants rate their thirst
Original Secondary Outcome Measures  ICMJE Same as current
Current Other Pre-specified Outcome Measures
 (submitted: February 1, 2016)
  • Amount of weight lost due to dehydration protocol [ Time Frame: 180 minutes ]
    participants will be weighed at the start and end of the dehydration protocol and % weight loss calculated
  • Body temperature [ Time Frame: 180 minutes ]
    Change in body temperature will be monitored throughout
  • Urine Osmolality [ Time Frame: 180 minutes ]
    Urine samples will be collected at the start and end of the procedure so that changes in osmolality can be measured.
Original Other Pre-specified Outcome Measures Same as current
Descriptive Information
Brief Title  ICMJE The Effect of Small Changes in Hydration on Cognition
Official Title  ICMJE How do Small Changes in Hydration Influence Cognition: A Mechanistic Investigation
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 Type  ICMJE Interventional
Study Phase  ICMJE Not Applicable
Study Design  ICMJE Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single (Participant)
Primary Purpose: Prevention
Condition  ICMJE
  • Cognition
  • Hydration
Intervention  ICMJE Dietary Supplement: Water
Participants will receive two cups of 150ml plain water
Study Arms  ICMJE
  • Experimental: Drink water
    Participants will receive two 150ml drinks of water during the dehydration protocol
    Intervention: Dietary Supplement: Water
  • No Intervention: Drink nothing
    Participants will drink nothing during the dehydration protocol
Publications *

*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
Recruitment Information
Recruitment Status  ICMJE Completed
Actual Enrollment  ICMJE
 (submitted: April 3, 2020)
Original Estimated Enrollment  ICMJE
 (submitted: February 1, 2016)
Actual Study Completion Date  ICMJE March 2016
Actual Primary Completion Date March 2016   (Final data collection date for primary outcome measure)
Eligibility Criteria  ICMJE

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
Sex/Gender  ICMJE
Sexes Eligible for Study: All
Ages  ICMJE 18 Years to 35 Years   (Adult)
Accepts Healthy Volunteers  ICMJE Yes
Contacts  ICMJE Contact information is only displayed when the study is recruiting subjects
Listed Location Countries  ICMJE United Kingdom
Removed Location Countries  
Administrative Information
NCT Number  ICMJE NCT02671149
Other Study ID Numbers  ICMJE HYD01
Has Data Monitoring Committee No
U.S. FDA-regulated Product Not Provided
IPD Sharing Statement  ICMJE Not Provided
Responsible Party Dr Hayley Young, Swansea University
Study Sponsor  ICMJE Swansea University
Collaborators  ICMJE Not Provided
Investigators  ICMJE Not Provided
PRS Account Swansea University
Verification Date April 2020

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP