As I am typing this, I am enjoying a 375ml stubby of Victoria Bitter, or as I like to call it, “VB”. It has a 4.9% alcoholic content, and from what I can see from my vantage point, a heck of a lot of water.
Why is it then, thet if I have 6 or 7 of these at a party and then come home and go straight to bed, I wake up in the morning dehydrated?
Yet when I have a glass or 2 of water before I go to bed, after drinking beer, I wake up the next morning feeling fine.
There is PLENTY of water in beer, why does it have no effect?
Because it’s the alcohol that dehydrates you. 5% of alcohol apparently has more effect to your brain than, say, 92% of water (allowing for 3% of other ingredients). That’s why without drinking a lot of water before bed, you wake up with a headache: factually, a dehydrated brain. The water you drink before bed prevents that because, unlike the water that was in your beer, it isn’t accompanied by 5% alcohol.
I think the discomfort of a hangover is caused by more than dehydration, the byproducts of your digesting the alcohol are part of it, too. And I don’t think it’s your brain that gets dehydrated, it’s your sinuses.
First off, NO, I don’t have a cite, but I will look around today.
Second, years and years ago I was reading about this. Apparently there is a chemical indicator in caffeine, nicotine AND alcohol which causes your (liver? kidneys? whichever have that job, I’m hazy on it) to think that EVERYTHING you process is waste…or at least a far larger proportion than normal. This is why drinking a lot of alcohol or coffee can make you have to pee all the time AND give you the runs.
Again, if I’m not mistaken, the hangover is caused by dehydration, and the dehydration is caused by your body processing out ALL of the water you’ve taken in, instead of just enough to convey the waste. When I set out to do serious drinking (say, on a birthday) I keep drinking glasses of water between glasses of whatever, and make sure I down another big glass of water before I go to sleep. If I have any available, I also down a B-complex because vitamin B helps flush out your system. When I have followed my own advice and stuck to this program, I have woken up perhaps a bit more tired than usual, but without the headache or feeling of overall ennui.
Like I said, I’ll see if I can find anything to back this up. I don’t remember where I read it and it was a long time ago, and I’ll be pulverised into slime by y’all if I don’t find a cite.
It is true that hangovers are caused by dehydration, but the OP asks WHY we get dehydrated. Well, its because your liver uses water to break down alcohol, so you lose water. Although dehydration is part of a hangover, a hangover can be much worse if you have been drinking wine for instance because it contains many more contaminants and toxins than purer alcoholic drinks (eg vodka).
Alcohol is also a diuretic. It basically makes your kidneys lose control of their water balance management. Without that, the natural osmosis takes over, and more water than usual goes out of your blood and into your bladder.
There are two effects of alcoholic beverages: 1) There is a direct osmotic effect in which the EtOH draws water out of tissues; and, 2) EtOH inhibits anti-diuretic hormone, leading to excessive water excretion by the kidneys. Both of these effects promote “dehydration.”
Furthermore, as regards the dreaded “hangover,” there are a few suspected culprits: 1) the presence of various aldehydes, ketones, and “higher alcohols” in the adult beverage, or such substances produced by your metabolism of said beverage; and, 2) the direct neurovascular effects of EtOH and cogeners.
As a migaineur, I can’t drink Scotch, Bourbon, or red wine, lest I suffer from a terrible headache. This is a pity, since I do love the taste of good Scots whiskey.
I don’t find beer dehyrdating. I sometimes have a beer after a race, since it’s given free (but rarely) and rationalize that the amount of water takes care of the alcohol. (I don’t know why they have the beer wagons after a race. It’s certainly contraindicated, but you know runners.)
However, I do find wine dehydrating. I usually have two wine glasses with dinner, but I really have to drink the water when I do. Beer, having less of an alcohol content and more water, does not affect me that way.
Beer, like tea, is a diuretic. It contains greater concentrations of certain salts and nitrates than your urine, and so your kidneys must remove a greater quantity of the low-concentration urine to keep the salt,etc. content constant. The body sacrifices water to avoid salt (etc.) poisoning.
