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Living rock (Pyura Chilensis) (i.imgur.com)

submitted by justshoothigh

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[–]GoliathPrime 37 ポイント38 ポイント

I'm laughing at the thought of people eating it when it tastes like iodine and destroys your liver. What the hell? Hey guys, let's go out of our way to find a marine animal so difficult to clean you need a hack saw to do it and let's eat it, even though it tastes like antiseptic and will probably kill us. Are Chilean's related to Klingons or something?

[–]purple_sage2 -6 ポイント-5 ポイント

Speaking of being killed after ingesting something, did you know that if you drank 100% purified water, you would die? The water is so pure that it absorbs all of the electrolytes in your blood stream and when it passed through you, you die. This is why water has minerals in it. Plus, purified water apparently tastes bad. Not 'bad' but it has no flavor and it's 'flat'.

[–]ChilyBean 25 ポイント26 ポイント

I was recently informed on here, quite rudely, that this was a myth.

[–]UNITA_Spokesperson -5 ポイント-4 ポイント

No, it certainly is not. Pure water, with absolutely no contaminants will certainly kill you, if you keep drinking it and nothing else.

The reason is that once it enters the body, it basically 'dilutes' the body's electrolytes. This is based on diffusion and the osmotic effect.

Imagine a single cell (for simplicity). Within that cell, certain ions exist in the cellular fluid at certain concentrations. Pluck that cell from the body, where it is existing in a healthy state and dump it in some totally pure water.

What happens is that you now have a concentration gradient (high/low). Let's just pick a random electrolyte. A potassium ion, for example. The inside of the cell has these potassium ions at a concentration of x g/L.

When the cell finds itself in pure water, there is now a great difference in ion concentration between the pure water, which has 0 g/L potassium and the inside of the cell, at x g/L. These concentrations are separated by the cell wall, which is porous.

Immediately, the system seek to equalise those concentrations. So you get a huge migration of potassium ions moving across the cell wall in an attempt to make the surrounding water the same concentration as what is in the cell.

Too much pure water and the results are disastrous - the cell will cease functioning correctly and at worst, die. Multiply that by trillions and trillions of cells and you now have a real problem.

And we've only considered one ionic species. The very same thing happens (but in reverse) when you consume alcohol. Too much and you're fucked.

So, unless you are dying of thirst, it's best not to drink pure water.

[–]Linquist 23 ポイント24 ポイント

I teach a cell biology lab, and this goofball shit comes up every semester during our tonicity and osmosis module. You are right that drinking enough water will kill you, and you have the mechanism more or less correct. Where you're off is that there is basically no difference from the human body's perspective between "pure" water and tap water.

Human extracellular fluid, for example, has a concentration of salts that corresponds to about a 0.9% solution of NaCl. Tap water concentrations tend to be less than 0.01% "Pure" water would be 0%. Both the tap and pure water solutions are extremely hypotonic compared to the fluid inside the cell, and the difference in their tonicity is negligible. Both tap and pure water are about equally dangerous here in large enough quantities. This is true around the boards for other solutes in tap and "pure" water as well.

Drinking only water will kill you. It doesn't matter if it's tap or "pure" water. The LD50 (lethal dose that kills the average subject) for rats is 90ml/kg. Humans should be similar, which means if you weigh about 150 lbs you'd need to drink about 6 liters of water in one sitting to manage to kill yourself. However, if you are eating ANY food during this time or spreading the water intake over several hours, then the amount of water needed would be much higher.

Anyway, this is alarmist bullshit. I've drank plenty of DI (deionized) water in the lab. It's fine. You can drink "pure" water if you like, it's no more dangerous than tap water. I don't know why you would, but whatever. I'm not a shill for distilled or DI water or anything, it just drives me nuts when people offer POTENTIALLY DEADLY HEALTH WARNINGS on subjects that they aren't qualified to.

[–]neuronauticist 3 ポイント4 ポイント

You are correctly describing the results of what happens (via osmosis) when a single cell is exposed to pure water. This is why it is inadvisable for anyone to receive electrolyte-free water intravenously unless they have a problem with too much of any given electrolyte in their blood.

In regards to drinking, it is NOT an problem that anyone with a functioning gut and kidneys would have, as the sole purpose of these organs is to regulate fluid and electrolyte balance in the body, and they do it quite well, at any volume of water that you would normally drink.

[–]ChilyBean 3 ポイント4 ポイント

I think the real argument is, one drink or nothing else for days. I was told as a kid not to drink distilled water, but have seen people touting it as a health drink - to 'flush out impurities'.

[–]Nepene 6 ポイント7 ポイント

No, it certainly is not. Pure water, with absolutely no contaminants will certainly kill you, if you keep drinking it and nothing else.

It's a fairly popular health fad. It's not hugely healthy but it's not especially likely it'll kill you- people haven't died en mass from drinking bottled water or distilled water.

The reason is that once it enters the body, it basically 'dilutes' the body's electrolytes. This is based on diffusion and the osmotic effect.

Water does this regardless. Your body tends to have far more minerals than water does even if it's hard water, and makes it up with food. Your body has numerous methods to control the ion balance of serum fluids, pure water isn't going to disrupt that. If you drink gallons of any normal water, yes, but pure water is hardly any special risk.

[–]failture -5 ポイント-4 ポイント

FWIW Pure water is quite a bit different than Distilled or Bottled water. Chemically pure water is quite difficult to produce and is not generally available commercially. I was told that it would suck electrolytes from your bloodstream and could cause your kidneys damage so we were advised to never drink it, however we did make killer coffee with it. Source- I was a chem tech at a nuclear plant water treatment facility

[–]Nepene 3 ポイント4 ポイント

Lots of people say this, but there's no real substantiation or scientific backing. The difference between distilled water and ultrapure water is if there's ppm or ppb in there. There's practically nothing in there anyway. Enough to screw up some super sensitive work, but not enough to make much difference for your body. By contrast, your body's sodium levels are measured in the parts per thousand. Any water you drink is going to suck electrolytes from your bloodstream. Unless it's like some energy drink or something seriously packed with stuff.

[–]iLurk_4ever 2 ポイント3 ポイント

So if I am in a shelter with supplies of food but only ~100% pure water jugs, can I just put some salt in it to make it drinkable or what? Pour some gravel in it for dem minerals?

[–]Nepene 4 ポイント5 ポイント

You can drink the water straight, Unita is making stuff up. Your kidneys can just piss out (convert to piss) the surplus water as long as you don't drink gallons.

[–]neuronauticist 2 ポイント3 ポイント

No, you're fine. Ignore him; he knows not what he's talking about.

[–]UNITA_Spokesperson -2 ポイント-1 ポイント

I don't want to get too out of my depth here. I'm a chemical engineer. I have no training in medicine.

I would cautiously say yes. I may even suggest it may not be necessary if the food supply is adequate.

Can someone else comment?

[–]bergdorf_bandit 7 ポイント8 ポイント

This conversation is a fine example of good ol' Reddit bullshittin'!

[–]UNITA_Spokesperson -3 ポイント-2 ポイント

?

[–]Solmundr 3 ポイント4 ポイント

It'll be fine if food supply is adequate, as you say. Even food with a tiny bit of sodium or potassium ion will suffice.

[–]Shoggoth1890 1 ポイント2 ポイント

Drinking too much plain water can kill you, it doesn't need to be 100% pure. The amount you have to drink to upset your electrolyte balance though is well beyond what people would normally drink, so people mostly don't have anything to worry about. The cautionary tale isn't "don't drink 100% pure water", it's "don't drink plain water to vast excess".

ETA: Here, have a link

[–]John_Q_Deist 0 ポイント1 ポイント

No, it certainly is not. Pure water, with absolutely no contaminants will certainly kill you, if you keep drinking it and nothing else.

That's a key distinction, right there.