Whether you prefer to drink tap water or mineral water is often a question of taste. But is one variant healthier?
Bottled water or tap water: what’s the difference?
In Germany, mineral water is subject to strict regulations and controls, which are laid down in the Mineral and Table Water Ordinance. Officially recognized types of mineral water are always offered with the name of the source and the place of origin.
There are also strict microbiological specifications. The composition of the mineral water must not be changed or the values fluctuate. However, a minimum content of minerals does not have to be proven, this was determined by an EU reform in 1980. Overall, there are therefore very large fluctuations in terms of the nutrient content of mineral water.
A test by Stiftung Warentest even shows that 15 of the 31 types of mineral water tested had only a low mineral content of fewer than 500 milligrams per liter.
Depending on the concentration of minerals, the mineral water must be labeled accordingly. For example, if the sodium content is below 20 mg/l water, the water may be labeled “mineral water suitable for low-sodium diets”.
Other special types of mineral water are
- desulfurized mineral water,
- de-ironed mineral water,
- calcium mineral water,
- mineral water containing magnesium,
- fluoridated mineral water and
- mineral water suitable for preparing baby food.
In Germany, tap water is mainly obtained from groundwater. Before it gets into the groundwater, the rainwater absorbed by the soil is enriched with various minerals from the different soil layers. Since the composition of the soil differs depending on the region in Germany, there are strong regional differences in how high the proportion of minerals and trace elements in tap water is.
The tap water in Leipzig, for example, contains 72.2 milligrams of calcium, 27.2 milligrams of sodium, 14.5 milligrams of magnesium, and 5.3 milligrams of potassium per liter.
In Germany, very strict quality parameters are applied to tap water. There are strict limit values for more than 40 different substances that must not be exceeded. The substances checked include the concentration of nitrate, but also heavy metals such as arsenic or lead. The water is also checked for bacteria.
Which important minerals are contained in mineral water and tap water?
There are some important minerals in tap water as well as in mineral water.
The body needs magnesium to activate the muscles, for the formation of proteins, and the transmission of nerve signals. The daily requirement for an adult is between 300 and 400 milligrams. From 50 milligrams per liter, water is generally considered to be rich in magnesium. With 108 milligrams per liter, Gerolsteiner is the best-known water brand.
Calcium is the main component of the human skeleton and therefore important for bone formation, but also plays an important role in muscle and nerve activation. On average, an adult needs between 1000 and 1200 milligrams of calcium per day. From 100 milligrams per liter, water is generally considered to be rich in calcium. Naturalis and Gerolsteiner Sprudel are among the best-known calcium-rich water brands.
Sodium helps the body regulate water balance. It is the main component of human sweat and is therefore particularly important for people who do a lot of sport or do physically demanding work.
The recommended daily dose for an adult is 1500 milligrams. In the case of high blood pressure, on the other hand, a low-sodium variant of mineral water should be used. Attention should be paid to a concentration below 200 milligrams, which is the case with most conventional brands.
Tap water also contains iron, potassium, and sulfates. However, these are smaller in quantity than those mentioned above.
Can tap water cover the daily need for minerals?
For a healthy diet, it is important to drink plenty of water to keep the body hydrated. However, drinking water alone is not enough to cover the daily nutrient requirement. According to the Stiftung Warentest, tap water contains just as many minerals, and some types of mineral water even contain more minerals, but these do not cover the daily requirement of a person.