British researchers find moderate coffee consumption can actually hydrate you just like water.
"In moderation, consuming caffeine probably is not going to dehydrate most people," said Dr. Dicky Shah at Kaiser Permanente Baldwin Park.
Shah says coffee does increase the body's loss of fluid and sodium, but not enough to reduce the amount of water the body retains.
In the study, one group of men was asked to drink four mugs of black coffee per day. The other group drank water. After several days, researchers found no significant differences in total body water, blood composition or urine.
"If you love to drink coffee and you're worried about becoming dehydrated, I would say it's good news," said Shah.
But Shah says this doesn't mean people should start drinking more. The caffeine in more than two or three cups can cause other health problems like acid reflux, anxiety and trouble sleeping. Plus, adding cream and sugary flavorings to coffee can amp up the calorie count.
Although the study wasn't done on tea or caffeinated sodas, Shah thinks similar results do apply. But he says the healthiest way to hydrate is with water.