Now you can’t make an excuse for having a low score at the exam because of not taking expensive brain-boosting vitamins. The key to exam success might be a glass of water.

That is the finding of a study conducted by Chris Pawson from the University of East London and his collaborators.

The researchers recorded the behavior of 447 undergraduate students divided in three groups in relation to whether students brought drinks, and the type of drinks (such as water, coffee, cola) they brought into exams. Of these, the more mature students (second year of degree study) were more likely to bring in water - 31% did so compared with 21% of foundation year and first-year students.

After taking students' academic ability into account, by examining coursework grades, the researchers found foundation students who drank water could expect to see grades improved by up to 10%.

Dr.Chris Pawson of the University of East London said that drinking water may have a physiological effect on thinking functions which can lead to improved exam performance.

Dr Pawson said, "Future research is needed to tease apart these explanations, but whatever the explanation it is clear that students should endeavor to stay hydrated with water during exams."