Clinical trial NCT02671149: The Effect of Small Changes in Hydration on Cognition
Official title: How do Small Changes in Hydration Influence Cognition: A Mechanistic Investigation
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Cognition
Hydration
Lead sponsor: Swansea University
Sponsor class: OTHER
First posted: 2016-02-02
Enrollment: 101
Sex: ALL
Minimum age (years): 18
Maximum age (years): 35
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

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.

Eligibility criteria: 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

Primary outcomes:
measure: Episodic memory - list of 30 words
timeFrame: change from 0 to 180 minutes after the start of the dehydration protocol
measure: Focused attention - Eriksen Flanker Task
timeFrame: change from 0 to 180 minutes after the start of the dehydration protocol
Secondary outcomes:
measure: Thirst (Participants rate their thirst)
timeFrame: change from 0 to 180 minutes after the start of the dehydration protocol
Other outcomes:
measure: Amount of weight lost due to dehydration protocol
timeFrame: 180 minutes
measure: Body temperature
timeFrame: 180 minutes
measure: Urine Osmolality
timeFrame: 180 minutes
Locations:
city: Swansea
country: United Kingdom
facility: Swansea University
state: West Glamorgan
Study officials:
References:
citation: Benton D, Young HA. Do small differences in hydration status affect mood and mental performance? Nutr Rev. 2015 Sep;73 Suppl 2:83-96. doi: 10.1093/nutrit/nuv045.
citation: Benton D, Jenkins KT, Watkins HT, Young HA. Minor degree of hypohydration adversely influences cognition: a mediator analysis. Am J Clin Nutr. 2016 Sep;104(3):603-12. doi: 10.3945/ajcn.116.132605. Epub 2016 Aug 10.