Does Decaffeinated Coffee Dehydrate You?

If you’re like me, have probably been nagged numerous times about how coffee is dehydrating or how I should switch coffee for water as I sip on numerous cups of coffee throughout the day..

I also drink decaf coffee after dinner sometimes, or before bed.. I was wondering if decaffeinated coffee has a dehydrating effect? And come to think of it, is regular coffee as dehydrating as people think it is?


Does coffee dehydrate you?


Lets settle this ongoing debate.

For years it has been said that coffee makes you dehydrated, just like other caffeinated drinks and alcohol.

However, this advice is based on a study from way bay in 1928.¬†Actually, as it turns out, this wasn’t a particularly rigorous study at all – it contained only three people! The result of this study has led people to believe for many years that coffee is dehydrating because it contains caffeine which is a diuretic.

More recent studies have shown that whilst yes, a diuretic does lead to increased urination, drinking coffee does not directly lead to dehydration. If you drink other fluids throughout the day, even those containing a diuretic, you won’t be at risk of dehydration, because of the liquid you are consuming alongside the caffeine.

Same goes for decaffeinated coffee – drinking decaf coffee will not dehydrate you. Instead, it will actually add to your daily fluid intake!


Does Decaffeinated coffee dehydrate you


It is better to look at liquids in terms of how well they hydrate you, instead of whether it is hydrating or dehydrating.

Any liquid will hydrate you, but some will perform excellently, like water and skimmed milk. Others will perform poorly at replenishing you, such as coffee and beer.

(Results from a study by the American Journal of Clinical Nutrition.)

Decaf coffee will hydrate you better than regular coffee, thanks to the reduced amount caffeine.
Note* No decaf coffee is 100% caffeine free, the caffeine is removed at the time of processing the coffee beans using water and either methylene chloride, activated charcoal, CO2, or ethyl acetate. After the decaffeination process the coffee will still have around 3% caffeine left in it.

This still means that decaf coffee is a better hydrator than regular coffee.

The points to take away from this post are:

  • Regular coffee and decaf coffee do not directly lead to dehydration.
  • Caffeine is a diuretic, which does increase how quickly you produce urine – but the quantity of liquid consumed along with the caffeine will stop you from becoming dehydrated.
  • The saying that coffee makes you dehydrated is based on a very small experiment back in 1928.
  • Decaf coffee will always have a small amount of caffeine left in it. (Around 3%)
  • Decaf coffee and regular coffee both add to your daily fluid intake.