Myth: does coffee cause dehydration? · Mind and Body Solutions

Myth: does coffee cause dehydration?

The short answer is: not really.

While caffeine is a mild diuretic—meaning it can prompt your kidneys to flush more sodium and water through your urine—the water used to brew the coffee typically offsets the fluid loss.

Net Hydration: For most people, the amount of fluid you consume in a cup of coffee is greater than the amount you "lose" due to the caffeine. Therefore, coffee actually contributes to your daily fluid intake.

Tolerance Matters: If you drink coffee regularly, your body develops a tolerance to the diuretic effect. You won't notice nearly as much of an impact as someone who only has a cup once a month.

The Threshold: Research suggests that moderate caffeine consumption (about 2 to 4 cups of coffee) doesn't significantly impact hydration status. You would generally need to consume a very high dose of concentrated caffeine without much water to see a dehydrating effect.

Even if it isn't dehydrating you, coffee can still cause dry mouth or increased heart rate, which sometimes feels like dehydration. If you’re feeling thirsty, it’s always a good call to alternate your lattes with a glass of plain water.

This study concludes (PMID: 24416202):

"Our data show that there were no significant differences across a wide range of haematological and urinary markers of hydration status between trials. These data suggest that coffee, when consumed in moderation by caffeine habituated males provides similar hydrating qualities to water."

So enjoy a good cup of coffee!!

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