Source: HEALTHY WATER Martin Fox, Ph.D.
Over the years many studies have been published on the relationship
between drinking water and cardiovascular mortality. Two beneficial
factors continually stand out – hardness and total dissolved solids. Both have been associated with lower mortality from heart diseases..
Hardness refers to the amount of calcium (Ca) and magnesium (Mg), or
calcium carbonate in the water. The more Ca, Mg, or calcium carbonate,
the harder the water, the less – the softer the water.
The first major study on drinking
water and heart disease was in 1960 by Schroeder. In his paper,
"Relation Between Mortality from Cardiovascular Disease and Treated
Water Supplies," the water in 163 largest cities in the United States
was analyzed for 21 constituents and correlated to heart disease. He
concluded "some factor either present in hard water, or missing or
entering in soft water is associated with higher death rates from
degenerative cardiovascular disease." (48)
In 1979 after reviewing
fifty studies, Comstock concluded, "there can be little doubt that the
associations of water hardness with cardiovascular mortality are not
Too many studies have reported statistically significant correlations
to make chance or sampling errors a likely explanation."( 16) He
suggests that the reason for this association is due to a "deficiency
of an essential element or an excess of a toxic one." Certainly a
combination of both is also possible.
Today after thirty years of research we are left with Schroeder’s
initial conclusion-drinking hard water results in less cardiovascular
disease than drinking soft water.
Yet over the years there have been several published reports analyzing
specific elements in drinking water and their possible relationship to
heart disease. One researcher studies zinc, another -copper, another
selenium, and so on. And as you read this mater-ial, you find an
inconsistent and confusing picture. But, if you look at the broader
picture, if you look at the studies on hardness, you will find very
consistent results the harder the water, the less heart disease deaths.
In most cases the harder the water, the more Ca and Mg is in the water.
However several interesting studies indicate that Mg might be the more
important of the two elements.
Professor Ragnar Rylader notes that studies in Switzerland, Germany and
Sweden show that when the Mg in drinking water exceeds 10-15 mgIL, the
rate of mortality fails in comparison to neighboring communities with
lower levels of Mg in the water. Some studies recommend 20 t~igIL as
the ideal Mg level. However, there are studies showing 6 to 8 mgIL is
highly beneficial while some bottled water manufactu1rers go so far to
claim that 90 mgIL is best. (46)(33)(34)(35). At this time I do not
believe that Mg is the all encompassing &~silver bullet" that some
claim. But I do believe it is important. Knowing the levels of Ca and
Mg in your drinking water is worthwhile. Look at both the hardness
levels and the specific amounts of Ca and Mg.
Before highlighting some of the major studies, let’s discuss TDS, total
dissolved solids. TDS is a measurement of all the minerals in drinking
water. TDS not only includes calcium and magnesium (the hardness
factors), but also zinc, copper, chromium, selenium and so on. Sauer
analyzed .23 drinking water characteristics in 92
cities ("Relationship. of Water to the Risk of Dying") and found people
who drank water higher in TDS had lower death rates from heart disease,
cancer, and chronic diseases than people who drank water with lower
amounts of TDS. (47)
Frequently, where the water is hard, the water
is also high in TDS. Although most studies on heart disease have not
looked at TDS, but only at hardness, this factor has been ever present
and may be playing a very significant role.
The more we try to isolate and study the impact of individual minerals
the more we can lose sight of the unifying, comprehensive, beneficial
factors present in water like hardness, TDS, and pH. Perhaps one of the
main reasons there are inconsistencies in the water story is simply
because we are obsessed to locate a specific isolated element that is
responsible for the beneficial effects of healthy drinking water.
Let’s look at some of the major studies. In Great Britain, the British
Regional Heat Study analyzed 253 towns from 1969 to 1973. They found
10% to 15% more cardiovascular deaths in soft water areas than in hard
water areas. They suggest that the ideal amount of hardness is
approximately 170 m~IL (or ppm-parts per rnillion). (50)
In the United States,
Greathouse and Osborne studied 4200 adults, ages 25 to 74 in 35
different geographic areas. Their findings also showed less heart
disease mortality in hard water areas than in soft water areas. (26) A
report by the Oak Ridge National Laboratory found that the calcium and
magnesium in hard water reduces the risks of heart attacks and strokes.
This study compared the health records of 11,400 Wisconsin male farmers
who drank well water from their own farms. The farmers who drank soft
water suffered from heart disease, whereas, the farmers who drank hard
water were, for the most part, free of the problem. (63)
Sometimes, the best experiments are those nature has been silent-ly
conducting for years. Some of the most revealing water studies
highlight two neighboring towns in which one town alters its hard water
to create a softer water. What are the results of this action? A higher
rate of heart disease mortality. We see this in the English towns of
Scunthrope and Grimsby. Both towns drank the same water with 444 mg/L
of hardness and had identical heart disease mortality rates. Scunthrope
softened its water to 100 mg/L of hardness and within a few years a
striking increase in cardiovascular deaths occurred. Whereas in Grimsby
the rate was virtually the same as it had been. (51) This pattern has
also been reported in the Italian towns of Crevalcore and Montegiorgio
and the Abruzzo region of Italy. (31) (44)
The National Academy of Sciences concluded, "An optimum conditioning of
drinking water could reduce the amount of cardio-vascular disease
mortality by as much as 15% in the U. S."(37) When looking at the
research, two facts stand out. First, there is a definite relationship,
a clear association between water hardness and heart disease mortality.
We should try to drink water that has approximately 170 mWL of
hardness; the level found ideal in Great Britain. Second, there is a
definite relationship with TDS and heart disease mortality. Higher
levels of TDS results in less heart disease. Proper levels of hardness
and TDS are two of the beneficial properties In drinking water
constituting a healthy drinking water.