There is no link between that cuppa of coffee now and getting dehydrated later.
According to a new research, drinking moderate amounts of coffee does not result in dehydration and contributes to daily fluid requirements in regular coffee drinkers just as other fluids do.
The researchers at the University of Birmingham School of Sport and Exercise Sciences in Britain found that the effect of coffee consumption on fluid balance cannot be directly compared with that of pure caffeine.
"Our research dispels earlier theories that coffee consumption can lead to dehydration and should be avoided, or reduced, in order to maintain a healthy fluid balance," said Sophie Killer, a doctoral researcher and lead author.
"This is the first study to directly assess the effects of a moderate consumption of coffee compared to equal volumes of water," she added.
Killer and colleagues measured the effects of moderate consumption of black coffee compared to the consumption of equal volumes of water on fluid balance and hydration status.
Fifty male participants, in two phases, were required to drink four mugs (200ml) of either black coffee or water per day for three days, said the study published in the journal PLOS ONE.
In the second phase, those who had initially drunk coffee switched to water and vice versa. The two phases were separated by a 10-day 'wash out' period.
The researchers found no significant differences in total body water or any of the blood measures of hydration status between those who drank coffee and those who drank water.
Furthermore, no differences in 24-hour urine volume or urine concentration were observed between the two groups.
"We found that consumption of a moderate intake of coffee - four cups per day - in regular coffee drinking males caused no significant differences on hydration indicators," concluded Killer.
