Beer and dehydration

June 27, 2010 2:30 PM

Would you eventually die of dehydration if you had only beer to drink?

I've read that due to alcohol's diuretic properties, after a few beers (and a trip to the bathroom) one is left more dehydrated than before, despite consuming the water content of the beer.

I'm having trouble getting my head around this, though. For example, I've read that people in medieval Europe drank beer all the time because the water was unsafe to drink. Were they just dangerously dehydrated all the time then?

Assuming that somebody had only beer and food with a minimal amount of water content (think crackers), would they eventually die of dehydration? If so, how quickly would this happen, compared to having nothing to drink at all?

posted by pravit to Health & Fitness (21 answers total)

I doubt it, but don't try it at home.
posted by nogero at 2:44 PM on June 27, 2010

As I understand it, most beer consumed in medieval Europe had very low alcohol content .

(Compare modern low-alcohol fermented beverages like table beer or kvas. I've met native Russians who were actually unaware that kvas contains any alcohol at all; it's considered a soft drink and is consumed by children as well as adults.)
posted by magnificent frigatebird at 2:49 PM on June 27, 2010

Probably not. You also get water from the foods you eat. But even if you ate just crackers and beer, I doubt you would die of dehydration, that said, you wouldn't be all that healthy either (think of Bowery bums). Beer is primarily water.
posted by fifilaru at 2:59 PM on June 27, 2010

You'd be pretty malnourished, but very much alive. And hydrated. Also seconding that we are not talking 10% DIPAs.
posted by fixedgear at 3:10 PM on June 27, 2010

According to an old Q&A at the New Scientist (quoted elsewhere, as the original doesn't seem to be online), you may stay hydrated and nourished if you pick the right beer and a couple of other liquid supplements:

Q: I have heard that it is possible to live on Guinness and milk alone. Is this true, or even partially true?’

A: This is not quite true. Guinness does contain many vitamins and minerals in small quantities, but is lacking vitamin C, as well as calcium and fat. So, to fulfil all of your daily nutritional requirements you would need to drink a glass of orange juice, two glasses of milk, and 47 pints of Guinness. — Nigel Goodwin, University of Nottingham

posted by maudlin at 3:18 PM on June 27, 2010

The reason this wouldn't work is that the diuretic action of beer works better when you're more hydrated. Your kidneys would preserve water better as you became less hydrated.
posted by Mr. Gunn at 3:19 PM on June 27, 2010

Water has a mildly diuretic effect on it's own. Yet if you drink too much of it at once you die of overhydration. It's the electrolytes, e.g. salt and sugars from crackers, that keep overall fluid content in balance. If all you're consuming is beer and nothing else then maybe you'd die of dehydration, if the alcohol poisoning doesn't get you first, but start adding in other things and you're a) increasing the sources of liquid and b) changing up the tonicity of what you're consuming so the straight diuretic effect is lost. Also, as Mr. Gunn pointed out, your body has pretty strong controls in place to stop it getting too far out of whack (a mechanism called homeostasis) so as long as you keep putting fluid in at the top you should be OK.
posted by shelleycat at 4:04 PM on June 27, 2010

pravit: For example, I've read that people in medieval Europe drank beer all the time because the water was unsafe to drink. Were they just dangerously dehydrated all the time then?

I've heard it seriously argued that that was exactly the case, and that many of the wars and other horrors of the day were due, in no small part, to the fact that everyone was severely dehydrated all the time. I don't really believe that, though.

Also, while the beers that people were drinking weren't high ABV compared to the high ABV beers on the market today, they were certainly higher in alcohol than 1-2%, as the alcohol was crucial to keep the beer safe to drink. Certainly when two gallons of beer a day were included as a part of a worker's ration, it wasn't a huge, high ABV beer, but if you gave them two gallons of kvas, they probably would have stormed the mansion.
posted by paisley henosis at 4:09 PM on June 27, 2010

I've heard it seriously argued that that was exactly the case, and that many of the wars and other horrors of the day were due, in no small part, to the fact that everyone was severely dehydrated all the time.

Frankly, I have wondered if the grimness of pre-industrial Europe was due to widespread FAS, for this very reason. I don't believe there's any way that could be proven, though.

Do you recall where you read that argument? I'd like to check it out.
posted by Countess Elena at 4:57 PM on June 27, 2010

I've tried this experiment for going on thirty years now. You need water. That's the basic element of staying hydrated. Beer is another thing altogether. You'll end up dehydrated and probably in a great deal of pain. It's better than nothing, but it's no substitute for water. Lick moisture from leaves like an anole if you must, but make water your main drink whatever else you do.
posted by metagnathous at 5:48 PM on June 27, 2010

It's not because of alcohol. It's because there's a lot of salt in beer. In order for your kidneys to excrete the excess salt, it requires more water than the beer contained.
posted by Chocolate Pickle at 7:52 PM on June 27, 2010

Countess Elena: Do you recall where you read that argument? I'd like to check it out.

No idea at all, sorry.

Chocolate Pickle: It's not because of alcohol. It's because there's a lot of salt in beer. In order for your kidneys to excrete the excess salt, it requires more water than the beer contained.

I'm pretty sure that's going to depend on how hard the water you use to brew is, though. I mean, Burtonised water, yeah, salty, but if you brewed with reverse osmosis water, where would the salt come from?
posted by paisley henosis at 9:00 PM on June 27, 2010

Salt gets added to the water during the brewing process because beer, like a lot of kinds of food, doesn't taste right without salt.
posted by Chocolate Pickle at 9:09 PM on June 27, 2010

(The recipe I used to use when I did homebrew included salt...)
posted by Chocolate Pickle at 9:11 PM on June 27, 2010

If you brew with water that has no minerals in it what so ever, then the beer will struggle to turn out, but if you brew with normal water than salts are an optional addition which can add a lot to some beers, but unless you are using distilled water or something similar you don't actually need to add more salt. [cite]

To bring it back to the point: the brewers in the middle ages did not salt their boil water or their mash or their beer. For one thing, I doubt that the majority of them could afford to waste the money on all that extra salt.
posted by paisley henosis at 10:42 PM on June 27, 2010

(The recipe I used to use when I did homebrew included salt...)

A Bud has 12mg of sodium, or less than 0.1% of the recommended daily intake.

And unless you were brewing Gose, you need a new recipe.
posted by obiwanwasabi at 1:56 AM on June 28, 2010

I've heard it seriously argued that that was exactly the case, and that many of the wars and other horrors of the day were due, in no small part, to the fact that everyone was severely dehydrated all the time.

Bullshit (I know you said you didn't believe it either!). Mainly because in terms of 'wars and horrors' there was nothing exceptional in the medieval period compared to any other in human history (if you're about to argue that there wouldn't have been massive mortality from the Black Death if everyone was just really well hydrated then you're an idiot).

Certainly when two gallons of beer a day were included as a part of a worker's ration, it wasn't a huge, high ABV beer, but if you gave them two gallons of kvas, they probably would have stormed the mansion.

So this is why the medieval Islamic world (which certainly did drink alcohol even though it was forbidden in Islam, though to much lesser extent than medieval Europe) was constantly in a series of revolts by the workers! Oh, wait, no it wasn't, because this theory is bollocks.

Frankly, I have wondered if the grimness of pre-industrial Europe was due to widespread FAS, for this very reason.

Please provide citation as to how pre-industrial Europe was grimmer than during the Industrial revolution. Medieval Europe seems to have had lower rates of TB, rickets, generally were taller, and with the exceptions of periodic famines were basically healthier than their 19th century equivalents. In terms of FAS - no evidence that the population were any worse at impulse control or had more cogitive problems than now (it's difficult to be sure when you're working from things like court records, so there is room for debate, but there is no evidence for your position).

Another point is that you're assuming that your only source of hydration is what you drink. Boiled dishes, like stews and porridge, were eaten by everyone regularly, which would have increased fluid intake as well. paisley henosis is totally right about the salt too - it was relatively costly and they would have had a far lower salt intake than we do.
posted by Coobeastie at 3:28 AM on June 28, 2010

Anyone doing this runs the risk of beer potomania, one of my favorite ailments to diagnose.
posted by treehorn+bunny at 6:47 PM on June 28, 2010

And the interesting thing is that, according to the linked article, beer potomania is associated with overhydration rather than under. So there's your hypothesis right out the window.

Drinking too much of anything without food is going to cause a problem, choosing semething relatively unsalty like beer or water makes it worse. Plus it's not at all similar to the people in medieval Europe who also ate normal amounts of food and probably consumed other liquids along the way.
posted by shelleycat at 8:22 PM on June 28, 2010

Thanks for the answers everyone.

So does beer dehydrate or hydrate, or is it some weird effect where it dehydrates you to a point, but hydrates you if you're below that point? Any more detailed scientific/medical explanations?
posted by pravit at 7:13 PM on June 29, 2010

Hydration or dehydration is caused by a big combination of factors, what you've been eating previously, what you eat while you drink, diuretic properties (or not) of what you're drinking, how much you're drinking and how fast, how hot you are, how hydrated you were to start with, your overall health and nutrition status, etc. So beer doesn't 'hydrate' or 'dehydrate' specifically, it plays a role in all that other stuff contributing to overall hydration and electrolyte balance (the electrolytes are really important in all this too, adding salt to your beer actually does change the outcome).

Remember water is a mild diuretic and yet we still drink that to be hydrated. And drinking too much water will still kill you from over hydration just like not drinking anything will eventually kill you from underhydration. Drinking a lot of alcohol at once so you're drunk and not drinking anything else will generally cause some degree of dehydration but it's not a simple, single effect.
posted by shelleycat at 7:27 PM on June 29, 2010