Skip to main content
OpenTrials
Completed

NCT Number: NCT02671149

The Effect of Small Changes in Hydration on Cognition

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.

Completed

Looking for future studies?

Notify Me

Key information

Conditions

Cognition Hydration

Age range

18 year–35 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Swansea University

Swansea, West Glamorgan, SA2 8PP, United Kingdom

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Water

Dietary Supplement

Participants will receive two cups of 150ml plain water

Primary outcomes

  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 outcomes

  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 outcomes

  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.

Sponsors and collaborators

Lead sponsor

Swansea University

Other

Registry information

Official study title

How do Small Changes in Hydration Influence Cognition: A Mechanistic Investigation

Important dates

Study start
2015
Primary completion
2016
Study completion
2016
First posted
Feb 2, 2016
Registry last updated
Apr 6, 2020

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.