Review paper on drinking water and cognition published

January 11th, 2011

Edmonds, C.J. (2010). Does having a drink of water help children think? A summary of some recent findings. School Health, 6(5), 58–60.

Water is the optimal drink for both adults and children. New guidelines specify how much children should drink during the day. Children are at greater risk of dehydration than adults. While English schools must legally provide drinking water for children, they differ in how they put this legislation into practice. Some schools allow children to have drinking water on their desks, while others restrict access. There are links between the type of access and the hydration state of children. In adults, there are well established links between dehydration and negative effects on cognitive performance. Recent studies suggest that dehydrated children also perform poorly on cognitive tests. More recent research has found that giving children a drink of water improved their cognitive performance on tests of memory, attention, and visual search tasks. These positive effects on cognition are likely to underpin positive effects on academic performance and providing regular access to drinking water in schools would be a cheap and easy way to improve children’s school performance. Further research is indicated to confirm the role of hydration in improving cognition in a UK population and to explore the links to academic and behavioural outcomes.

new paper published – The effect of intrauterine growth on verbal IQ scores in childhood: A study of monozygotic twins

October 21st, 2010

Given the adverse neurobiological effects of suboptimal nutrition on the developing brain, it is of social and medical importance to determine if the global prevalence of poor intrauterine growth causes lasting cognitive deficits. We examined whether suboptimal intrauterine growth relates to impaired cognitive outcome by comparing birth weight and cognition in monozygotic twins and considered whether within-pair differences in birth weight were related to within-pair differences in IQ scores.
A total of 71 monozygotic twin pairs (aged 7 years 11 months to 17 years 3 months) participated. The Wechsler Intelligence Scales for Children, Third Edition, was administered and verbal IQ (VIQ) and performance IQ (PIQ) scores were calculated. Regression was used to relate within-pair differences in birth weight to within-pair differences in IQ scores.
VIQ but not PIQ score was affected by prenatal growth restriction. The results suggested that the mean advantage for heavier twins relative to their lighter co-twins can be as much as half an SD in VIQ points. In pairs with minimal discordance, heavier twins had lower VIQ scores than their lighter co-twins.
Our study results suggest that lower birth weight in monozygotic twins can also have a negative long-term impact on cognition both in infants who are small at birth and also those with birth weights across the spectrum. Studying monozygotic twins enabled us to examine the effect of reduced intrauterine growth on cognition independently of confounding factors, including parent IQ and education, and infant gender, age, genetic characteristics and gestation.

UEL Promising Researcher Award 2010-11

July 15th, 2010

Caroline has been awarded a second UEL Promising Research Award for her research. The funded project will investigate the effect of dehydration and water consumption on cognition in older adults.

new PhD student begins studies

April 5th, 2010

Paula Booth has started her PhD examining the effect of hydration on cognition. Welcome Paula!

PhD studentship opportunity

December 18th, 2009

The School of Psychology at UEL will be offering a University Studentship for a full-time MPhil/PhD student commencing in February 2010.  The studentship will cover fees and a bursary of £12,000 per annum. This is a competitive scheme with a number of projects. My project is entitlted, “Does having a drink help you think? The effect of water consumption on cognition and mood in adults.”

You can find more details about the application process here. This studentship is only open to home students.

And more details on my project are below


While there are studies that suggest that dehydration negatively affects cognition in adults1-2, not only are the results of these studies inconclusive, but they confound the effects of dehydration with the methods by which it is induced (heat stress, fluid restriction and or exercise3.  A related question is whether drinking water can aid cognition under normal conditions (i.e. no or mild dehydration).

There is a developing area of research on the positive effects of water consumption on cognition in children4-7, suggesting that having a drink of water positively affects performance on tasks employing visual attention and visual memory.  However, there is very little research examining the effects of water consumption on cognitive performance in non-dehydrated adults.  The research that has been conducted suggests that water consumption positively impacts on subjective ratings of alertness8.  It also improves cognitive performance in the case of individuals who were thirsty before they had a drink8.

The research question that will be addressed by this PhD is: what are the effects of water consumption on cognition and mood in adults?

By negotiation with the supervision team, this could take a number of different directions. It could, for example, examine what specific cognitive processes are affected by water consumption. Alternatively, it could describe and quantify the water consumption effect, for example, by evaluating the amount of water drunk, the length of interval between water consumption and improvements in performance and/or the duration of the effect. It could also explore how initial thirst interacts with water consumption to affect cognition.


1. Cian, C., Koulmann, N., Barraud, P. A., Raphel, C., Jimenez, C., & Melin, B. (2000). Influence of Variations in Body Hydration on Cognitive Function: Effect of Hyperhydration, Heat Stress, and Exercise-Induced Dehydration. Journal of Psychophysiology, 14, 29-36.

2. Gopinathan, P., Pichan, G., & Sharma, V. (1988). Role of dehydration in heat stress-induced variations in mental performance. Archives of Environmental Health, 43, 15-17.

3. Lieberman, H. R. (2007). Hydration and Cognition: A Critical Review and Recommendations for Future Research. Journal of the American College of Nutrition, 26(suppl 5), 555S-561S.

4. Benton, D., & Burgess, N. (2009). The effect of the consumption of water on the memory and attention of children. Appetite, 53, 143-146.

5. Edmonds, C. J., & Burford, D. (2009). Should children drink more water? The effects of drinking water on cognition in children. Appetite, 52, 776-779.

6. Edmonds, C.J. & Jeffes, B. (2009). Does having a drink help you think? 6–7 year old children show improvements in cognitive performance from baseline to test after having a drink of water. Appetite

7. Fadda, R., Rappinett, G., Grathwohl, D., Parisi, M., Fanari, R., & Schmitt, J. A. J. (2008). The benefits of drinking supplementary water at school on cognitive performance in children, 41st Annual Meeting of the International Society for Developmental Psychobiology. Washington D.C.

8. Rogers, P. J., Kainth, A., & Smit, H. J. (2001). A drink of water can improve or impair mental performance depending on small differences in thirst. Appetite, 36, 57-58.

9. Schretlen D. (1989). The Brief Test of Attention. Psychological Assessment Resources: Lutz, Fla.

10. Cambridge Cognition. (2004). The Cambridge Neuropsychological Testing Automated Battery (CANTAB).

11. Bedard, A.C., Martinussen, R., Ickowicz, A., Tannock, R. (2004). Methylphenidate improves visual-spatial memory in children with attention-deficit/hyperactivity disorder. Journal of the American Academy of Child and Adolescent Psychiatry, 43, 260-68.

12. Levy, R., Sahakian, B.J., Warburton, D.M., Jones, G., Gray, J. (1992). Effects of acute subcutaneous nicotine on attention, information processing and short-term memory in Alzheimer’s disease. Psychopharmacology, 108, 485-94

13. Sahakian, B.J., Mehta, M.A., Goodyer, I.M. (2004). Methylphenidate improves working memory and set-shifting in AD/HD: relationships to baseline memory capacity. Journal of Child Psychology and Psychiatry, 45, 293-305.

14. File, S.E., Hartley, D.E., Elsabagh, S., Ali, O., Williamson, E.M. (2005). Differential cognitive effects of Ginkgo biloba after acute and chronic treatment in healthy young volunteers. Psychopharmacology, 179, 437-46.

15. Goodwin, G.M., Cowen, P.J., Harmer, C.J., McTavish, S.F.B., Clark, L. (2001).Tyrosine depletion attenuates dopamine function in healthy volunteers. Psychopharmacology, 154,105-11.

16. Goodwin, G.M., Cowen, P.J., Harmer, C.J., McTavish, S.F.B., Clark, L., McPherson, M.H., et al. (2001).  Antidopaminergic effects of dietary tyrosine depletion in healthy subjects and patients with manic illness. British Journal of Psychiatry, 179, 356-60.

new paper on drinking water and cognition published

October 15th, 2009

Edmonds, C.J. & Jeffes, B. Does having a drink help you think? 6–7 year old children show improvements in cognitive performance from baseline to test after having a drink of water. Appetite (in press).


Abstract.  Little research has examined the effect of water consumption on cognition in children. We examined whether drinking water improves performance from baseline to test in 23 6-7 year old children. There were significant interactions between time of test and water group (water/no water), with improvements in the water group on thirst and happiness ratings, visual attention and visual search, but not visual memory or visuomotor performance. These results indicate that even under conditions of mild dehydration, not as a result of exercise, intentional water deprivation or heat exposure, children’s cognitive performance can be improved by having a drink of water.

Paper on drinking water and cognition published

March 11th, 2009

Edmonds, C.J. & Burford, D. (2009).  Should children drink more water? The effects of drinking water on cognition in children. Appetite, 52, 776-779.

These results suggest that even children in a state of mild dehydration, not induced by intentional water deprivation or by heat stress and living in a cold climate, can benefit from drinking more water and improve their cognitive performance.

New Researcher appointed

January 25th, 2009

Rosanna Crombie has been appointed to carry out research on the effect of drinking water on cognition. Rosanna has previously worked in the Department of Psychology, at the University of Kent, and in the Infant Lab in the Department of Psychology at Goldsmiths.

UEL Promising Researcher Grant Awarded

October 9th, 2008

Caroline has been awarded one of UEL’s Promising Researcher Awards to carry out a research project entitled, “Are we drinking enough water? The effect of hydration on cognition.” This will examine the effect of drinking water both in adults and in children.