Actually, as restated in a February 17 article in the New York times, recent studies have shown that caffeinated beverages do not significantly contribute to dehydration.
The myth about water comes from a missunderstanding of an old study. The study showed that humans need 64 oz. of water on average a day to remain healthy. Someone who didn’t read too deeply read this as meaning we need 8 cups of water a day to stay healthy, and went about spreading the word that we all weren’t getting enough water. After all, no one drinks that much water unless they live in a hot desert.
The fact that the myth spreader missed was that most of our food is made up of large amounts of water already, and this water was taken into account in the study. For example, most fruits are 80-90% water, meats are 30-50%, etc. When these are taken into account, most people get plenty of water. Basically, if you are thirsty, drink, if not, don’t worry about it too much. If you are thirsty alot, you should see a doctor.
This myth got spread around alot, so expect to keep seeing it in various forms from now until the end of time, things like this tend to die hard. ‘Myths that refuse to die’ is my favorite pet peeve.
You’d be better off to stick with studies than to go by my anecdotal experience but after cutting my coffee intake for gastro/intestinal reasons I noticed that I had to drink more water to make up the difference.
I have resurrected this thread because I found the following while googling for another thread.