Drinking water can sharpen your mind, research shows.
The effect is particularly marked if a person is thirsty.
The University of East London researchers believe that once thirst is relieved, the brain is left to focus on the task in hand.
They carried out an experiment on 34 men and women who completed a number of mental tests twice â€“ once after a breakfast of just a cereal bar and again after a cereal bar washed down with a bottle of water.
None had eaten or drunk anything overnight and all were asked how thirsty they were at the start of the experiment.
Those who said they werenâ€™t thirsty were equally quick at the test of reaction time with or without the water.
But those who were thirsty sped up after having a drink, making them up to 14 per cent quicker than before, the journal Frontiers in Human Neuroscience reports.Â
The researchers think the water helped by freeing up the parts of the brain that were busy â€˜tellingâ€™ the body it was thirsty.Â