Changes in the mineral composition of food as a result of cooking in "hard" and "soft" waters.

During the last decade many epidemiologists have found an inverse relationship between water hardness and cardiovascular mortality. It seems unlikely that this relationship can only be attributed to a deficiency of calcium and mangnesium in drinking water, because only 10-20% of the total daily intake of calcium and magnesium is derived from drinking water. The purpose of this study was to investigate changes in the mineral composition of food to investigate changes in the mineral composition of food when cooking with waters of different hardness. The most significant differences were found for calcium; the concentration of this element in potatoes and vegetables usually increased when cooking with hard-water types, while a decrease was noted when soft water was used for cooking.