Why are “health” sites so full of shit? It’s getting to be the case that when I see “health” (or worse, “wellness”) in the title of an article, I have the same aversive reaction I get when I see the word “family”. It’s a good word that has been hijacked by loons.
The latest mania in the “health” community is the danger of reboiling water. I read this and was appalled at the basic misunderstandings in it.
You know how you see the steam coming off of the water when you boil it? Well, that steam is made up of volatile compounds, and they burn out of the water, turn into gasses and leave the water as steam. When your boiled water cools down, those dissolved volatile gasses, as well as minerals, settle back into it. When you re-boil the water, the chemical compounds are changed again; however, the way they are changed is actually harmful.
When water is re-boiled, dangerous components will collect in the water instead of escaping from it. What type of harmful substances? Usually re-boiled water contains:
You probably wouldn’t buy a bottle of water that said it contained arsenic, would you? Of course not! So, why would you re-boil water if there is a chance that it could contain arsenic?
Healthy minerals are retained in boiled water, but even they can become dangerous when they become amassed in re-boiled water. For example, calcium salts can collect in the water, and they can cause gallstones and kidney stones if enough is consumed.
First, what steam is made of is primarily water. Volatile compounds will only be there in trace amounts, and they’d be there whether you boiled the water or not, and boiling will actually get rid of them. Try the experiment: add a little alcohol to the water. Boil it. Let it cool. The alcohol boils off first and is lost to the atmosphere. It doesn’t transmute into toxic chemicals and precipitate back. Minerals don’t boil out of the water.
The only way arsenic or nitrates or fluoride will get into your reboiled water is if they were already there in the first place. There is no magic change in “compounds”.
The one concern is very different: when you boil water, the volatile stuff (almost entirely just plain water) in the kettle escapes into the air, while the non-volatile stuff remains behind. That means that when you boil water, the minerals and salts in it become gradually more concentrated. We have very hard water where I live, and if I boil down a pot of water, I can see a rather nasty residue accumulate. It doesn’t taste good either.
But it’s there even if I don’t boil the water. It’s just more dilute.
This stuff isn’t that hard to understand. If you don’t understand it, you shouldn’t be writing health advice.