OK, so I haven’t even had a beer in quite some time, much less the amount needed to perform the following experiment, so I put it to my less tetotalled (holy crap, is that a word?) Dopers:
I recall being about to drink about 1.5+ liters of beer before having to urinate. I couldn’t even imagine being able to drink an equivalent of water (and I drink a lot of water during the day. In fact, I just drank about a liter in one go).
Now, beer certainly seems to go down easier than water, but certainly they take up the same amount of space in my stomach. Does the alcohol affect my needing to urinate (i.e. does it stay in the stomach longer so the alcohol can be absorbed before moving to the bladder?), or is it that when I’d drink, I’d be in a socia situation and, if I was drinking that much, I’d be having fun and not want to leave, so I waited until I was nearly going to wet myself whereas when I drink water, I’m usually sitting around by myself so going to take a piss really doesn’t affect my experience.
Or, am I just misremembering this phenomena and there’s no difference at all?
Water is just water, beer has lots of other crap in it. Now, the kidneys are a complicated organ, but siffice to say, they remove things like minerals, salts, water, and other stuff from our blood. Water does not have any of this stuff, so when it finally enters the bloodstream from the stomach and intestines, it actually dilutes the blood, lowering it’s osmolarity. The balance back out the osmolarity, cells in the body will take in some water. However, unless you are dehydrated, thecells will take just a small amount, so the kidneys will have to remove all the excess water and place it into the bladder.
When you drink beer, you are putting all that other stuff in your blood along with the water. Chances are, this will raise the osmolarity of the blood. In an effort to restore osmolarity, cells in the body will give up water (hence why beer dehydrates you.) However, as before, the cells merely giving up or taking something won’t do the job alone, so the kidney will try to filter out as much of the impurities, salts, minerals, etc… as it can. It will have to take some fluids, but much less water, since it is trying to save it. There will most likely br a higher concentration of urea and ammonia in your urine after a night of drinking.
Your experience is exactly the opposite of the way that it is supposed to be. Beer is a diuretic that should make you urinate faster and more than an equivalent amount of water.
You can’t drink 1.5 liters of water at once, not because you’d have to pee before you were done, but because your tum would be full before you got it all down.
My theory- they dont actually take up the same amount of space. Beer has dissolved CO2, which will cause your stomach to expand prior to being vented/belched. Increased stomach volume allows more beer to be held, pre-kidney.