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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

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.

Condition or disease Intervention/treatment Phase
Cognition Hydration Dietary Supplement: Water Not Applicable

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.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 101 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single (Participant)
Primary Purpose: Prevention
Official Title: How do Small Changes in Hydration Influence Cognition: A Mechanistic Investigation
Actual Study Start Date : September 2015
Actual Primary Completion Date : March 2016
Actual Study Completion Date : March 2016

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Drinking Water

Arm Intervention/treatment
Experimental: Drink water
Participants will receive two 150ml drinks of water during the dehydration protocol
Dietary Supplement: Water
Participants will receive two cups of 150ml plain water

No Intervention: Drink nothing
Participants will drink nothing during the dehydration protocol

Primary Outcome Measures :
  1. 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.

  2. 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.

Secondary Outcome Measures :
  1. Thirst (Participants rate their thirst) [ Time Frame: change from 0 to 180 minutes after the start of the dehydration protocol ]
    Participants rate their thirst

Other Outcome Measures:
  1. 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

  2. Body temperature [ Time Frame: 180 minutes ]
    Change in body temperature will be monitored throughout

  3. 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.

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   18 Years to 35 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

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

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT02671149

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United Kingdom
Swansea University
Swansea, West Glamorgan, United Kingdom, SA2 8PP
Sponsors and Collaborators
Swansea University
Publications automatically indexed to this study by Identifier (NCT Number):
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Responsible Party: Dr Hayley Young, Dr, Swansea University Identifier: NCT02671149    
Other Study ID Numbers: HYD01
First Posted: February 2, 2016    Key Record Dates
Last Update Posted: April 6, 2020
Last Verified: April 2020