Drinking waters that do not contain minerals, in particular drinking waters that do not contain magnesium and calcium, are known as soft waters or distilled waters and are considered by many scientists to be unhealthy. Recent scientific papers presented to a World Health Organization (WHO) conference indicate that distilled water leads to dilution of the normal electrolytes dissolved in body water. This leads to a transfer of water from red blood cells and other body cells and a redistribution of water between body compartments, which may compromise the function of vital body organs. Symptoms at the very beginning of this condition include tiredness, weakness and headache.
Soft water low in calcium and magnesium may cause ill-health. Soft water has caused acute health problems in mountain climbers who had prepared beverages from melted snow. A severe disease coupled with brain oedema, convulsions and metabolic acidosis has been reported in children whose drinks had been prepared with soft or distilled bottled water. In general, soft or distilled waters that do not contain magnesium or calcium increase the elimination of sodium, potassium, chloride, calcium and magnesium ions from the body. For over fifty years, soft drinking waters have been associated with increased mortality. In one study, reported to the World Health Organization (WHO), within weeks or months of a population using home filtration of water a range of complaints occurred including heart disorders, tiredness, weakness and muscle cramps. These complaints were thought to be correlated to low magnesium and calcium levels in the filtered water.
In addition, soft waters absorb many contaminants from their source and may absorb many dangerous chemicals and heavy metals from water pipes and other delivery systems. A scientific paper in a World Health Organization (WHO) report has stated that soft waters containing a low mineral content are unstable and are highly aggressive to materials with which they come in contact.