Ultra-pure water can kill you


I call bullshit. Has there ever been a study or a documented case in which a creature was killed by drinking ultrapure water? I suspect we get enough minerals from food such that drinking deionised water wouldn’t matter.

Thing is, there isn’t pure water in nature - everything has minerals in it. So the only cases where creatures are going to have died from drinking pure water are going to be from cases involving humans, because that’s the only place to get pure water.

That said, it’s a well documented fact that pure water leaches salts from the environment it is in. This is why drinking too much distilled water can be harmful - your body is sapped of minerals when you excrete the water. If you keep replacing it with pure water, you keep diluting your mineral content.

Drinking a little bit of distilled water won’t hurt you. Drinking only distilled water will. It takes time, though.


What if you drank distilled water to wash down your Fritos?

By this standard regular water would kill you too, assuming you drank only tap water and never ate anything.


I don’t think anyone disagrees with the mechanism or the statement “Drinking ultra-pure water will leach minerals out of your body (somehow, over time)” but I would also call bullshit on the statement “Ultra-pure water can kill you” without any backup at all.

“Regular” water has a normal mineral content. Tap water is full of minerals - both purposefully so, and incidentally. It’s incomparable.

Theoretically a person could survive on pure water alone, so long as they had a diet of food that gave them enough mineral content to make up for the dilution effects of the pure water. But if your diet is insufficient to replace the salts you lose, bringing them back up to a reasonable level, your health will directly suffer.


The “somehow, over time” you speak of with mystification is a process known as osmosis.

[quote=“RoryBarr, post:5, topic:37123”]I would also call bullshit on the statement “Ultra-pure water can kill you” without any backup at all.
Your body cannot operate without a proper salt content. The basic functions of your cells do not operate without certain salts. If you leach more salt out of your body than you put back into it with your dietary intake, it will cause your body functions to fail, and you will eventually die.

If that’s not sufficient “backup” for you, then I’m not sure how to convince you otherwise. Maybe someone else can explain it in a way you’ll grasp.


& don’t forget that most food is cooked with “regular water”, so food itself confounds pure water consumption in any of these kinds of studies.

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Worth watching the video right to the end for the wink (and his reaction to it).

I’m dubious that “ultra pure” water is much more likely to hurt you than regular tap water.

It is possible to OD on regular tap water. Takes some effort though, something like 10% of your own body weight in a fairly short period of time. Still it happens occasionally.

However just how pure is “ultra pure” water vs regular tap water vs blood?

Regular tap water has 1-135 mg/L of Calcium. “Ultra pure” presumably has near 0. Human blood has 85-102 mg/L. Thus “Ultra pure” is hardly different, compared to human blood, from ordinary low calcium water.

Tap water has 0-4 mg/L of Magnesium. Human blood has 17-23 mg/L of Magnesium.
Again the fact that the “Ultra pure” has 0.00001% of the magnesium of human blood rather than 1% is not likely to be important in the short run.

So let us say you have some regular low-mineral tap water. Like your city water is fed from rain/snow. Portland Oregon perhaps. Portland’s water is pretty low in minerals. 1mg/L Ca 0.6mg/L Mg. In order to extract from the rest of your body as much Magnesium as a 1 L of ‘Ultra Pure’ water it would take about 86/85ths as much Portland tap water. AKA 1.011L.

Now if you drink only highly purified water for a long time… maybe, eventually. But still it’s hard to believe that the residents of Portland Oregon are 1% away from some bizarre deficiency diseases… or is it?

Quick, get those people some minerals!


Basically, all of that math is ruined as soon as the person eats something.


I found a case report of three sickenings and one actual death following repeated accidental haemodialysis against distilled water (whoops! how do you make that same mistake four times?) - yet people who are receiving dialysis have pre-existing morbidity so it’s unclear whether just drinking it would matter so greatly for an otherwise healthy person.

…and Heavy water is known to be toxic once it replaces about 25% of the body’s total water content (and presumably that D2O was also distilled ZOMG!), but I’m not sure that counts.

Some plants actually grow better in distilled water than regular tap water…


No, it won’t. A adult human with healthy kdineys would need to drink about 17 liters or 4.5 gallons of distilled waters over the course of a couple of days to experience adverse effects or drink about half that in 9 hours to mess up his blood plasm.

Without eating or drinking anything else, because other foods and drinks contain the same minerals.



No one framed drinking distilled water from time to time as being an immediately dangerous thing.

The effects occur over a long period of time for humans (much faster for smaller, more sensitive animals like fish in aquariums), and depends largely on your dietary intake - if you replace more salts with what you eat than you leach out with what you drink, you can drink all the distilled water you like.

That said, the effects do exist, and they can kill you - if you leach more salts than you replace.

Is tap water better for you than distilled water? A little bit, yeah - assuming we’re discounting things like pathogens, which distilled water has far less of. Is it a big enough difference that you need to be worried? Probably not, unless you’re not getting enough salts.

It’s like the difference between eatting rice and eatting wheat. Rice technically is more calorie efficient than wheat, so it’s technically better at preventing starvation. Except most of us don’t live right on the edge of a healthy caloric intake, and changing from rice to wheat isn’t going to cost us enough calories to make a difference and push us into the red unless we’re already close to starving in the first place.

That said, you don’t need to die to suffer adverse effects. If you’re playing a competitive sport, for example, and you decide that instead of drinking the electrolyte-rich “Sportade” of your preferred brand, you’d rather drink distilled water, that can make the difference between having energy to keep playing, and feeling absolutely miserable and possibly even passing out from exhaustion and exertion.

If the idea was that there was some acute problem, like ordinary water overdose, they might die before they eat a lifesaving frito.

But for the long term, yea.

Well, that’s like claiming that gold contains instant poising when administered by gun. :slight_smile:

I’ve got a bottle of deionised water, and some Daphnia right here. See you tomorrow.


okay… s/creature/vertebrate/ … we know you can dehydrate and kill a slug by pouring salt on its back, and I suspect that means we could burst a slug (also fish and aquatic animals) by immersing them in DI water … but mammals?

You guys argue about the silliest things…
…without inviting me

Scurvy is a good example of specific imbalance of vitamins that had routinely occurred to large groups of people.

Theoretically, a imbalance of other nutriest (ie, salts) could occur sometime in the future if the food one eats doesn’t have, say, zinc or something, and the only source of liquid is DI water.

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I think that the range of city water supplies (just out of large US cities) shows that there are vast numbers of people who drink water which is close enough to zero mineral compared with our bodies to put a very heavy burden of proof on anyone who claims that zero mineral water is even a long term health risk, and that it is absurd to think that it is an acute one. However it is just barely plausible that there is some long term effect.

In advance I warn that I will be unconvinced by studies funded by the mineral water industry.

Of course the company tells people not to drink it.
A) They surely aren’t approved for that.
B) They probably don’t want the crazy people who might try it attempting to sue them.
C) It’s just stupid. Those machines are fairly expensive to run, and while it doesn’t seem likely to be at all harmful to me it is also not going to be healthful.

BTW if you want to create a perfectly clear ice cube you need to avoid bubbles, not minerals in the water.

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