DEHYDRATION IN HEALTHY ADOLESCENTS AFFECTS BRAIN STRUCTURE
& FUNCTION
Equating to same level of shrinkage expected in Alzheimers’ Patients over
two and a half month period
Research paper published in Human Brain Mapping* reporting medical study of 16-18
year olds, identifies that whilst dehydration may not immediately appear to affect
brain function in the short-term, for teenagers taking GCSE’s or A-Levels over
consecutive days, performance could be significantly affected
Leading wellbeing and hydration expert, Water for Work and Home, has recently
sponsored a medical study at King’s College London on the dehydration affects on
brain structure and function in healthy adolescents. The results of the study,
designed and carried out by Neurosense, in collaboration with the Newcomen Group
of scientists and business professionals, have identified that hydration needs to be a
major issue for adolescents, their parents and, crucially, their schools. This could be
particularly important in the run up to and during the GCSE and A-Level exams.
In particular the study identified that significant negative effects of dehydration with
structural changes in the brain equated to the same level of shrinkage expected in
Alzheimers’ patients over a two and half month period, or 14 months of ageing in
otherwise healthy individuals.
It has been observed that dehydration causes shrinkage of brain tissue and an associated
increase in ventricular volume. Negative effects of dehydration on cognitive performance
have been shown in some but not all studies, and it has also been reported that an
increased perceived effort may be required following dehydration. However, the effects of
dehydration on brain function are unknown.
But greater insight has now been provided in the study sponsored by Water for Work and
Home, which has been published in Human Brain Mapping*. This was led by Matthew J
Kempton and Marcus Smith and investigated the question using functional magnetic
resonance imaging (fMRI) in 10 healthy adolescents. Each subject completed a series of
exercises which resulted in dehydration. They were then tested for their cognitive
performance.
The study found that dehydration following the exercises led to a marked increase in frontoparietal brain areas necessary to perform an executive function task (Tower of London)
compared to a control condition. Cerebral perfusion during rest was not affected. The
increase in response after dehydration was not paralleled by a change in cognitive
performance, suggesting an inefficient use of brain metabolic activity following dehydration.
This pattern indicates that dehydrated participants exerted a much higher level of neuronal
activity in order to achieve the same performance level. Given the limited availability of brain
metabolic resources, these findings suggest that prolonged states of reduced water intake
may adversely impact executive functions such as planning and visuo-spatial processing.
“Given that there isn’t always any immediately observable effect on function from
dehydration, we are therefore particularly concerned about the possible longer term effects
on individuals who aren’t sufficiently hydrated” explained Professor Gemma Calvert, Chair of
Applied Neuroimaging, University of Warwick and a Co-Founder of NeuroSense. “Just
because you can’t tell that someone is dehydrated from their behaviour that doesn’t mean
their brain and body aren’t immune to the effects.”
And this is precisely what the research confirmed. “The research identified that reaction
times in the acutely dehydrated were no worse than those not dehydrated, when looking at
immediate short-term effects”, continued Professor Calvert. “But, crucially, fMRI neuroimaging results showed significant negative effects of dehydration with structural changes in
the brain that equated to the same level of shrinkage expected in Alzheimer’s patients over a
two and half month period, or 14 months of ageing in otherwise healthy individuals.
“In particular, an increase in neuronal activity required to perform a complex thinking task
was detected in the acutely dehydrated, compared to the non-dehydrated, which suggests
that the human brain compensates for dehydration by working harder. But given the frugal
nature of brain function, it seems unlikely that such effort could be sustained and, as a result,
there could be a decline in performance over the working day.”
Ben McGannan, Managing Director of Water for Work and Home believes this study
provides some important pointers for adolescents, their parents and their schools as we
head into the schools exam season. “ We strongly believed that that dehydration was an
issue in effecting students’ performance, but we sponsored this research to give us clear
evidence. And it now appears that whilst students may be able to tackle one exam a day
whilst dehydrated, if they have several exams to take on the same day, lack of regular
access to drinking water could have a seriously detrimental affect on their results.
“Clearly the simplest way to tackle this issue is to allow students to bring drinking water into
exam halls as well as ensure that drinking water is easily accessible near exam halls. But we
know that some schools are concerned about students’ need to visit the toilet and therefore
aren’t quite as willing to encourage consumption of water through the school day. There’s
also an issue of what students are allowed to take into exam halls.
“But this new research sends alarm signals that long-term effects of dehydration amongst
adolescents could be quite severe if not tackled quickly.”
Water for Work and Home is a business that focuses on wellbeing, including hydration and
its importance at and during work. In particular, the company has been addressing the
issues of hydration in schools. It has been running a programme – ‘We Love Water’ specifically focused on pre-schools, primary and secondary schools to improve
understanding and awareness of the importance of hydration in the school day.
In one project alone, focusing on hydration in Pre-school groups in Kent, 73% of
practitioners think the ‘We Love Water’ programme has been beneficial, encouraging
children to drink more water and learn how to take responsibility for their own hydration.
*Dehydration Affects Brain Structure and Function in Healthy Adolescents has been
published in Human Brain Mapping, 2010.
The full paper can be found at http://dx.doi.org/10.1002/hbm.20999
The Pubmed link is http://www.ncbi.nlm.nih.gov/pubmed/20336685
END