How can certain liquids we drink, like coffee, soda, and alcohol, dehydrate us? Aren’t they all mostly water? Shouldn’t they hydrate us instead?

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How can certain liquids we drink, like coffee, soda, and alcohol, dehydrate us? Aren’t they all mostly water? Shouldn’t they hydrate us instead?

In: Chemistry

3 Answers

Anonymous 0 Comments

They do. That was just your mom trying to get you not to drink so much soda or whatever. Or beverage companies who make higher profit from water.

Anonymous 0 Comments

Caffeine and alcohol have diuretic effects — they signal your kidneys to dump a bunch of extra water into your urine. If you don’t have enough extra water in your system to make up for this “water dump”, you get dehydrated.

That said, coffee, tea, and soda don’t dehydrate you very much because as you noted, you’re consuming a bunch of water along with them — to replace the water you’ll lose. It’s concentrated caffeine such as straight espresso, energy drinks, or caffeine pills that will leave you with a water “deficit”.

Alcohol depends on concentration. 5% beer will very slightly hydrate you. 13% wine will only dehydrate you a little. 40% liquor, though, will definitely leave you in a bad way. In fact, most of the cause of a hangover is dehydration, which is why liquor typically causes the worst hangovers (unless you also chug a bunch of water to compensate).

Anonymous 0 Comments

this is kind of a common misconception. and everything i am about to say comes from a talk i listened to from a nutritionist who works with Division 1 (college) and Olympic athletes.

If you’re severely dehydrated, pretty much all liquid drinks apart from hard liquor and beer and wine, will help you. Alcohol is the real one that doesnt work well.

The problem with alcohol is that the chemical alcohol is a diuretic, it makes you pee. so youre still taking in the water in the drink, but the alcohol is stimulating your kidneys and bladder to pee out more water. but even then, if you’re severely dehydrated, low % alcohol beverages will probably help you than just letting yourself go without drinking anything.

Another is high concentration shots of espresso won’t really help you, as caffeine also stimulates going to the bathroom.

But most drinks, sodas, coffees. teas, sports drinks, will hydrate you. The kicker is that they just wont hydrate you as well as plain old water. So when youre working hard, sweating a lot, you should be drinking plenty of water. But if youre just sitting around all day, a cup of coffee and a glass of soda and no water aren’t going to lead to you shriveling up like a grape.