Re: the hard vs soft water and cardiovascular disease research, one of the explanations put forward was that soft water generally came from areas rich in acidic soils, and that it leached more lead from pipes than hard water. Now that much of the lead piping has been removed from the water supply infrastructure, the amount of lead in soft water drinking supplies will have diminished. The scientific paper linked to above was published back in 1972, when we lived in a soft water area and had lead pipes.