The water factor and mortality from ischemic heart disease: a review and possible explanations for inconsistent...

The question of the relationship between water hardness and mortality from cardiovascular diseases is far from being settled. Marked discrepancies in the results of various studies in this area exist and there is a great need for closer examination of the reliability of measuring water hardness and other water characteristics. There is also a need for standardizing these measurements and for accounting for certain important questions in designing studies of this nature. This article reviews the results of various studies on the "water factor," points out their discrepancies, presents additional evidence from the Province of Manitoba against the "water factor;" and explains possible sources for discrepancies in the findings of various studies. Based on the evidence so far available, it is too early to universally accept the "water story" and to make recommendations for discouraging the softening of hard water as a measure for preventing cardiovascular disease mortality.