Turns Out That Coffee Doesn’t Actually Dehydrate You

We’ve all had a friend tell us to cut down on coffee whenever we complain about a headache, stating that it’s common knowledge that coffee dehydrates you. However, it turns out that might just be an old wives tale, no more true than the quip ‘starve a fever, feed a cold’.

According to Live Science, the myth originated after a study performed in 1928 that noted increased urination in people who drank caffeinated beverages, and suggested that caffeine was a diuretic. Since then, coffee has enjoyed the undue adjective of being dehydrating.

However, science says it’s a bit more complicated than that! “[T]he truth of the matter is, a small increase in urine output has little to do with dehydrating the body,” Armstrong told Live Science.

He added that any increase in fluid input will lead to an increase in urine output. “If you drink a liter of water, [urination] will increase,” Armstrong said. “Doesn’t mean you shouldn’t drink water.”

“In a healthy body, it’s very unlikely that a few cups of coffee are the cause of your dull skin, or headaches, or overall feeling of dryness—at least, not through the mechanism of dehydration,” says Dr. Haythe. Looks like the cause of your headache at work might not be down to an extra cuppa so caffeinate away!