The Effect of Small Changes in Hydration on Cognition
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ClinicalTrials.gov Identifier: NCT02671149 |
Recruitment Status :
Completed
First Posted : February 2, 2016
Last Update Posted : April 6, 2020
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Condition or disease | Intervention/treatment | Phase |
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Cognition Hydration | Dietary Supplement: Water | Not Applicable |
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 : | 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 |

Arm | Intervention/treatment |
---|---|
Experimental: Drink water
Participants will receive two 150ml drinks of water during the dehydration protocol
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Dietary Supplement: Water
Participants will receive two cups of 150ml plain water |
No Intervention: Drink nothing
Participants will drink nothing during the dehydration protocol
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- 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.
- Thirst (Participants rate their thirst) [ Time Frame: change from 0 to 180 minutes after the start of the dehydration protocol ]Participants rate their thirst
- 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.

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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

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 ClinicalTrials.gov identifier (NCT number): NCT02671149
United Kingdom | |
Swansea University | |
Swansea, West Glamorgan, United Kingdom, SA2 8PP |
Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: | Dr Hayley Young, Dr, Swansea University |
ClinicalTrials.gov 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 |