Dehydration's role in learning and memory
cshl.eduHonestly I don't get why we don't educate more on how to manage water consumption and hydration. It's highly situation dependent and both about listening to your body (natural thirst) and pre emptively anticipating water needs.
If you are going on a multi day backpacking trip in the desert you are going to be consuming a lot more water than sitting at your computer in an air conditioned office reading HN. And you also are going to need to be very cognisant of consuming adequate amounts of electrolytes (particularly magnesium and salt). You also would be wise to "camel up" at least a bit beforehand to make sure you are at peak hydration at the beginning (and of course anticipate carrying enough water with you or knowing potential water sources you can filter from).
People who are into running also become aware of this and those who do any activity in extremely cold and dry environments.
In addition most people have a base level of water loss (even while sleeping) through your skin that varies but is I believe around a half liter (specifically 400ml or 14 fl oz) per 24 hours. This is not the typical sweat out of your armpits from being a bit too hot - it's known as "insensible perspiration".
Water management is a very valuable skill and much more valuable than just trying to have some blanket "liters per day" recommendation. And getting water from your food is never a bad idea either !
The more I age the more important hydration turns out to be. Gastric issues, joint pain, blood pressure, weight problems, kidney stones, bad breath, constipation.. and now brain issues too?
Do yourself a favor, and start drinking a ton of water!
Not too sure - an overload of water can actually be dangerous i think.
Jumping in here with relevant experience - because you're absolutely right.
In 8th grade (~16 years ago) my substitute biology teacher organised a "Water drinking competition" poised to elevate our understanding of stomach capacity, etc.
Two of us went to hospital, and ~5 (including myself) had to take multiple days off of school and recover.
It's very dangerous. He lost his job.
There was a lady who died from the same thing:
https://abcnews.com/GMA/jury-rules-radio-station-jennifer-st...
What was exactly his thinking here? Do biology teachers study biology because that’s kind of the first things you learn (saline concentration, kidney, etc…)
At least where I am, substitute teachers don't have to study anything in particular at all. You simply need to have completed X number of credit hours at an accredited institution, no actual degree or certificate is required and the coursework can be literally anything. As a newly-graduated history major I signed up to substitute teach out of desperation, and was sent everywhere from kindergarten to calculus.
Since no one is being quantitative, here's a medical source:
https://my.clevelandclinic.org/health/diseases/water-intoxic...
> In some people, water intoxication symptoms can develop after drinking about a gallon (3 to 4 liters) of water over an hour or two.
> More than 32 ounces (about a liter) of water per hour is probably too much.
Only if it gets ridiculous. Like after a marathon drinking a gallon on the spot (and dying from it).
Drink 2-4lt a day and you'll be fine.
It’s actually dependent on your individual biology and the environment that you are in.
You need more hydration in hot climates than in cold damp ones. Also your activity influences how much hydration you need.
Ps I don’t think the article is about how much water you drink. (Edited to make the last sentence clearer)
Water is poisonous in that too much of it will disrupt electrolyte balance and can be fatal.
It's one of the risks with taking MDMA, there are some documented cases where people died from drinking too much water when rolling.
Everything is poisonous at high doses even oxygen.
"[E]ven oxygen" is funny because it is absurdly reactive and will explode when given the opportunity, and way back when it destroyed pretty much all life on earth except the early cyanobacteria that produced it.
Edit: And yeah, I didn't imply what you're responding to, I described the mechanism for water poisoning.
> start drinking a ton of water!
But not too much as you don't want water poisoning!
A ton is definitely too much.
... at any given moment.
7 litters...
...Not that much... 3ish liters spread out over the day is good. Too much water will strip your body of electrolytes and salt.
I recently upped my water intake and can report that my skin and mood feel better. I caffeinate with a strong coffee and 2 cups of tea in the morning, and around 12 I switch to pint glasses of water every 2 hours or so until 6-7 o'clock.
Yea 2.5-3l seems to be the proper amount. Only drawback is having to pee every 30 minutes.
That's an advantage - it means you're not sitting e.g. at a computer monitor and keyboard for too long. Getting up twice an hour (to pee or not) greatly reduces the potential for ergonomic harm that desk jobs - especially computer use -are known for.
Fair :D I walk everywhere anyway so I think I'm good in that regard
Bug == Feature
If you're peeing that much then evidently your body is not using all that water you're consuming. Either it's more than you need, or you're lacking in electrolytes and should increase electrolyte intake alongside the water.
Your body doesn’t use up water turning it in to nothing. You are meant to pee out what isn’t lost to sweat.
By that logic, if I drank the right amount of water with 100% accuracy for multiple days, I'd only have to pee every few days.
I’m not arguing that 100% of water consumed can be retained, just that peeing every 30 minutes means you have an unnecessarily large surplus. This is simply a truth.
Parent is correct. NHS sources say upto 7 times during the day is normal and "Every 3 to 4 hours is considered healthy. Going every 1 to 2 hours usually means you either have an overactive bladder or are drinking too much at once."
Saying every 30 minutes is normal is just the same as advocating drinking too much water
3 liters everyday actually to keep muscle and brain work properly.
200ml every waking hour?
Seems excessive.
I have a bottle of 2.5liters. One bottle of water everyday from 7am to 8pm. It’s my habit for several years.
it's a matter of habit. 3l of liquids per day is what various doctors in different (european) countries have recommended me over the years.
Are we sure this is not just harmless and arbitrary information being parroted? Do we have verifiable sources other that anecdote? I find it hard to believe that there is just a single value for water intake across the massive biological spectrum that is humanity and expect to see a range when this conversation comes up. You're also getting water from foods, which I am sure is not being accounted for. Reminds me of the 10k steps a day that just happened to be "correct enough" to be believed and acted on. The truth is much more nuanced and depends on a number of factors in a person's physical health.
Without concrete verifiable findings, the best we can do is learn to pay attention to our bodies and drink maybe a little bit more water than we think we need to.
Overdrinking water is an American mania. You don't need to drink 3 liters.
https://abcnews.com/Health/Wellness/waterlogged-america-drin...
The European doctor quoted certainly said "3 liters" from both drinks and food (especially vegetables). In Europe I think we drink between 1 and 2 liters per day in actual water, depending on how dry the weather is.
I always laugh about those ridiculously large water bottles American carry and how they remind you all the time that you must drink water as if I did need it. I wonder why that happens.
Agreed. Being in the Midwest US, my intake also varies widely, depending on weather or season, physical activity, and the foods I've been eating.
I'm not entirely dismissive of doctors, be they European or American, as most I've encountered do have the patient's best interest at heart. But they are also human, and it is very easy to stick with the safe and easy answer rather than do the work to find the real answer. So when I hear claims like that, I immediately doubt them, assuming it is placeholder information because we do not know the actual answer. Unfortunately, a lot of our media in the US considers such "placeholder information" to be actionable, and ends up convincing the public (including doctors) of its veracity.
Americans don't eat vegetables though
They also eat plenty of salty processed foods.
sure, there are different recommended amounts, the EFSA recommendations are 2.5l per day for a grown up man and 2l for a woman[0]. I'm a bit bigger than the average so I got 3l as a recommendation when I was on a diet or when I had specific issues.
But I didn't mean to imply everyone should drink it, just that it's not hard to drink that much. And yes, of course you ingest a lot of water through other means too.
[0] https://efsa.onlinelibrary.wiley.com/doi/10.2903/j.efsa.2010...
I’ve always been extremely suspicious of constant water consumption. No other mammal seems to do this. Even the ones that require a lot of water like horses will only drink when they’re thirsty or while eating.
The point is you shouldn’t wait to drink until you feel thirty. That’s too late. Your muscle has been consumed by then.
Its aggravated because the "water sensor" appears to fail early with age. Elderly people tend to not get the thisty feeling as often, but get dehydrated anyway.
Indeed. That’s why I form the habit to drink 3 liters everyday to keep my urine white transparent.
I wonder how much of the effects of ageing are due to cascading failures downstream of alterations like these. For example, it's common for people to lose teeth in advanced ages. How much of this is due to dry mouths from insufficient water intake? Fallen teeth then may become entry points for infections, et cetera. Perhaps fixing a few early causes we can avoid a lot of negative effects and live more, without the need to go full spartan in lifestyle discipline.
I don’t know the exact things. I only know that diabetes would make this loss tremendously. As to teeth loss, it’s mainly because periodontitis but not age though it always goes worse as the age increases because of their life behaviors.
No other mammal eats cooked or baked food. Raw meat or raw plant contain more water than our food.
Most other animals have typical lifespans that don't top two decades.
Tl;Dr blame Gatorade marketing.
The book "waterlogged" does a good takedown of the myth. Basically only you need to drink when you are thirsty.
It’s a glass of water an hour. Hardly excessive.
It doesn't do anything to drink so much water. It is a purely American myth/trend.
https://abcnews.com/Health/Wellness/waterlogged-america-drin...
I feel much better when I drink more water: head, eyes, and body. And if I don't drink enough water during the day I'll cramp at night. Drinking lots of water to lose weight is nonsense – on this I agree.
I bet that your body needs more water if you eat ungodly amounts of salty processed food, just to flush all that shit out again.
A few big sips.
Why
This is bullshit.
https://abcnews.com/Health/Wellness/waterlogged-america-drin...
True. The body is perfectly capable of telling you when it needs water, it's called being thirsty. If you're thirsty, drink, otherwise don't.
sort of correct. As one ages the body starts doing a poor job of signaling thirst.
https://medlineplus.gov/ency/article/003086.htm
> As people age, they are less likely to notice their thirst. Therefore, they may not drink fluids when needed.
Please correct me if wrong but this has almost nothing to do with broad human dehydration or hydration.
I think it is an interesting finding and it would be interesting to hear more about the implications from someone in the field.
I only broadly understand this is some kind of peeking behind the curtain of some process that was not fully understood before
"Dehydration" in this article is the chemical process of separating magnesium atoms from water molecules. It is not about drinking enough water.
Most of the comments here are based on the title alone. Like always.
You are correct, title is wrong. Blame this communicator. It feels that the person that wrote the text lacks understanding of chemistry or oversimplified too much. More appropriate term for removal of water around an ion is “desolvation”.
No, dehydration is the common term when it's specifically water that's being removed.
Exactly, when I read the article the first thing I thought is "why is this on hacker news??"
On an absolute tangent, every kid today has a water bottle. It's a constant priority for us when we leave the house, and when we arrive at the destination, it's "stack yours with the rest of the kids'".
I never had a water bottle growing up. Was I just constantly dehydrated? Seems like it.
Some schools don’t allow children to leave the classroom to get a drink of water unless it’s at recess or between classes. So that’s why they carry water bottles nowadays.
Kids aren’t allowed to go to the toilet in the middle of a class?
Though I don’t remember not being allowed to drink something between class breaks ever being a problem growing up. Classes aren’t that long.
The other thing is that we mostly only had glass bottles back then, so of course kids wouldn’t carry those around.
Progress! When I was in school we weren't allowed to leave class OR have a water bottle. If you had food... good luck, that was like the worst school crime for some reason.
Leaving the classroom to pee was frowned upon during lessons, and during breaks obviously there was a queue.
Same for us.
I think as kids were were indeed constantly thirsty when playing in the streets, but on family trips my mom would have a big water container, so maybe it's just a kids/parents split.
What baffles me is the rise of water bottles in school, we just went to drink from the bathroom faucet when I was a kid.
Yep, or the hose that was being used to water the playing field. Ah the sweet taste of pfas on a hot summers day
>Was I just constantly dehydrated? Seems like it.
No you weren't. It is a health fad, a mania.
https://abcnews.com/Health/Wellness/waterlogged-america-drin...
It is compensation for all the sugar, caffeine and UPF causing dehydration IMO. And aircon perhaps.
People in Spain, Portugal, Italy etc don't carry 2 gallon water bottles everywhere.
The ones who have better diets are just going along with the crowd (though not necessarilyin better shape), using the oversized pacifier to signal they're healthy ("people who exercise have water bottles. Therefore I must show off a water bottle")
And kids are products of the parents
yeah same here. Also my wife drinks at least 3 liters a day... I think I'd struggle to stomach more than a liter of liquid on a normal day. (not counting hard work or hot weather.)
One can get used to quite strange life styles. One could be very active, drink nothing but coffee and alcohol. If they feel a bit sluggish thats just normal. If one gets used to being sluggish (from any deficiency) fixing it might make sleeping difficult or one ends up working harder than one should. If the job is a mindless grind gaining mental clarity might feel terrible.
hmmm food for thought.
Drink water until the color of your urine is clear. Once it is, there is no benefit to drinking more.