is coffee dehydrating?

[Guest]

Does coffee dehydrate you? I love it, but i do always seems to have a taste for water after drinking it. I dont know if its actually dehydrating though. Ive heard both answers, which is it???

[TimD]

Well, I've always thought it could lead to mild dehydration, but never really looked into it closely, so after reading your post I did a search on it, as it was an interesting question, fact or myth. I searched under "coffee and dehydration" using the MSN search engine, but google or dogpile would be just as good. I got a ton of hits, and from just a quick look, it appears to be fact, but I suggest you do a search for yourself to answer your question.
tim

[Ironman]

There isn't really anything that dehydrates you. However it is a diuretic, which is probably what you mean. Liquid goes through faster, so you have to replace it by drinking more water. You only dehydrate by having more water going out than you have coming in.

[kevin harris]

iron man i am surprised at you...normally your advise is on the money.
i am referring to the:

--------------------------------------------------------------------------------

There isn't really anything that dehydrates you


must be you have never drank way too much jim beam and fell asleep before you chug a gallon of water!!!! :)

[Ironman]

Alcohol is a very strong diuretic. Maybe "There isn't really anything that dehydrates you" wasn't the best way to phrase it. I wanted to state that a diuretic only causes dehydration if you don't replace what has passed through. So you cause water to pass through more quickly, but you can also replace it at a faster rate and not dehydrate. After a lot of drinking I have between 1 and 2 quarts of water. That usually does the trick. No Jim Beam though. I'm more of scotch kind of guy. hehe :)

[wrenelesidil]

Here is something that may be interesting. One of the main reasons why coffee is a diurretic is because of the high levels of caffiene. This is one of the main reasons why pregnant women are steered clear of caffinated beverages during pregnancy. If a pregnant woman becomes to dehydrated, the body can no longer support the fetus and will go into labor. In the Washington D.C. area around July 4th there are a lot of pregnant women in the E.R. because of dehydration.

[zeratum]

Alcohol is a very strong diuretic. Maybe "There isn't really anything that dehydrates you" wasn't the best way to phrase it. I wanted to state that a diuretic only causes dehydration if you don't replace what has passed through. So you cause water to pass through more quickly, but you can also replace it at a faster rate and not dehydrate. After a lot of drinking I have between 1 and 2 quarts of water. That usually does the trick. No Jim Beam though. I'm more of scotch kind of guy. hehe :)

Water molecules are used when the liver metabolizes the ethanol molecule:
http://www.chemhelper.com/alcdehyd.html

So even if you don't pee or sweat out any water, one can still become dehydrated by drinking alcohol.