After looking at the various attacks and behavioral problems of German immigrants over the past couple of months....I sat over the past day and did a fair amount of research/reading into brain damage from dehydration. It's an interesting topic.
It doesn't matter if you go and read material from the Brit medical folks, the Mayo Clinic, or natural health freaks....if you go and get dehydrated...among the dozen-odd things in your body that area affected, is the brain.
Cells in the brain rely upon water to hydrate things, and flush out the system. If you try to go eight hours without liquids....you will start to find thinking and calculating lessen....increasing the strain on you as well.
There's also the threat to your blood pressure.....dehydration lowers blood pressure. So there is a drop in the amount of oxygen reaching key components.
It's also a fact that if you don't stay hydrated, and you go into a stroke....it's four-times more likely that the outcome of the stroke will be extremely negative (not the kind of stroke that you recover from).
Why all of this matters? Well, there's Ramadan. Your mission if life as a Muslim is that you must shut down food and drink from sun-up to sun-down during the period of Ramadan....meaning in July in Germany.....roughly 16 hours at the peak. If you did this year after year....one might guess that in a decade....you've damaged your brain enough to trigger mental instability or at a very minimum....limit your thought process.
No university, as far as I can see.....as ever done a study on this, and I doubt seriously that they'd want to center in on this topic because of political implications. But with just general information on dehydration which is public knowledge, you'd have to ask some really stupid questions and wonder about the fragile nature of some urbanized society and their safety.