The mineral balance of the human body.
Filtered, demineralised tap water using osmosis technology is still very popular with consumers in Fuerteventura. With this system you can eliminate the smallest amounts of minerals out of the de-salinated seawater and protect your coffee machine and boilers from fast corrosion. But how healthy or harmful is water without minerals for us?
If living beings were to feed exclusively on demineralised water, they would soon suffer from "hypotonic hyperhydration" or simply from "water poisoning". Minerals are vital for our body, and we absorb the majority of them through our food. Compared to the low salt concentrations in common mineral waters, our food is the main source of the necessary minerals and trace elements. Provided, of course, that we eat not only artificial food, but a balanced Mediterranean diet.
This becomes clear in a direct comparison of the potassium or sodium concentration in fruit with that of a litre of mineral water. For example, to get to the potassium content of an apple (144mg/100g) or of a mango (190mg/100g), we would have to drink about 7-10 litres of mineral water (mineral water about 30mg per litre). Fresh Fuerteventura goat cheese contains about 800mg sodium/100g and a delicious Canarian banana with its about 14mg calcium weighs up to one litre of mineral water.
Thus, those who like to drink pure, filtered water and eat some fresh fruits, vegetables, wholemeal and milk products in addition usually have a good mineral balance.
Accordingly, it is hardly possible to demineralise by drinking two litres of pure water a day.
By the way, doctors advise adults to drink 30ml of fluid per kilogram of body weight - or even more simply: enough to keep the urine clear. Children up to 10 kg body weight should drink around one litre of fluid per day and 50ml per additional kilo of body weight (20 kg = 1.5 litres of fluid/day). In southern climates it is especially important for adults to drink enough, because already through breathing we lose about 0.3-0.5 litres of fluid per day. In addition, there are also some amounts due to perspiration and our metabolism. Urine production and excretion detoxifies our body and maintains the balance of body water and salts.
And what our kidneys do is enormous: if we drink five litres in one day, we neither gain weight nor swell. If we only drink half a litre the next day, we are neither lighter nor dry out. Our kidneys practically always keep the water level of the body at the same level and adjust the urine production to the amount we drink. Only if we would drink more than about 15 litres or less than 0.5 litres per day would our kidneys be overstrained and not be able to maintain the water level in our body. Our kidneys filter about 150 litres of fluid per day. Of this, they return about 99% back into our body, the rest is excreted as urine. In other words: our kidneys regulate and control the composition of the urine, our electrolyte and acid-base balance. A real tour de force. If we drink too little - you can see this from the dark colouring of the urine - we make our kidneys work harder and they become stressed.
Conclusion: Drinking pure, filtered and/or demineralised water is no problem at all as long as we eat healthy, mineral-rich food. In any case, we should drink enough so that our kidneys can work properly.
(Edited from article by Heike Bludau)