A question about the article
which discusses demineralized water and health from the World Health
A recent question from a visitor:
I have also been doing a
great deal of research and experiments on water quality and was very
interested to come across your web site. I am a qualified nutritional
therapist and have been seeking ways to make high quality water in the
city for those of us not lucky enough to have our own spring water. I have
a RO system in my house and like you I have found it difficult to find
reliable information regarding the health risks of drinking demineralised
water. I recently came across a W.H.O guide that I thought you might be
interested in reading which seemed to indicate there are health affects
from drinking completely pure water:
Like you, logically I wouldn't have thought the minute amounts of minerals
in natural water would make a difference to health and yet the research
does not seem to support this view. Also, it is interesting to note that
minerals is aqueous solution seem to be absorbed better by the body that
those in food or supplements.
I just thought you may be interested to read the report and would love to
hear your views on it.
Thanks for the link, Tim -
I cover the whole issue of distilled water
here, but I discuss this
specific paper below because it is one of the two recent sources for the
claim that drinking distilled water is harmful to the ordinary person.
the other article is Early
Death Comes With Regular Drinking Of Distilled Water by Zoltan P. Rona
that I address in an
letter to Dr. Rona that I sent him asking for evidence to support
his claim (with no reply yet).
I read the WHO document very carefully, because I
thought that an article, presumably endorsed by the WHO, would contain
some good, scientifically valid information. Yet after reading the
paper, I remain very skeptical about a lot of the information presented in it.
I don't know if you looked through the references, but most of them were about population studies showing differences between groups that drank hard vs. soft water. That observation is fairly common in the literature, but there is, to the best of my understanding, no consensus among researchers on the CAUSE of the slight, variable,
and sometimes non-existent association between higher rates of various diseases and the population
soft water . I have never seen the difference conclusively explained by the actual difference in levels of calcium, magnesium, and other minerals between the two populations.
The main point is that soft water (lacking calcium, magnesium, and other
"hardness minerals") is NOT distilled water, and one cannot use negative health
effects of drinking soft water (if any are conclusively demonstrated) to support
a claim that distilled water (containing no minerals or other contaminants) is
It is fairly tedious to track down every reference used by an author making an argument or proving a point and try to determine if the author of the paper in question used the reference properly to support the argument
or whether the investigator(s) experimental methods were sound. I only looked at a couple of examples.
A lot of his references were from what appeared to be obscure journals that would be difficult to
I will make a few comments below, but the best article I have found to discuss
the findings in the WHO paper is
Clean the Water: When it is muddied by Misinformation by the
Canadian Water Quality Association
Kozisey presents 6 sections that he
introduces as "The possible health consequences of low mineral
content water consumption are discussed in the following categories:"
1) Direct effects on the intestinal mucous membrane, metabolism and mineral homeostasis or other body functions.
At the end of this section Kozisek discusses water intoxication ((hyponatremic shock) and states:
"A more severe course of such a condition coupled with brain oedema, convulsions and metabolic acidosis was reported in infants whose drinks had been prepared with distilled or low-mineral bottled water"
I tracked down a paper written by the same authors on the same topic several years later (which included the two 1993 cases in the 1994 CDC article) and added several additional cases. The relevant section is quoted below:
Hyponatremic Seizures Secondary to Oral Water Intoxication in Infancy: Association With Commercial Bottled Drinking Water
- Robert C. Bruce and Robert M. Kliegman.
If that link doesn't work, go to Pediatrics
home page and search for the document
From Bruce and Kliegman's paper "Infants of parents living in poverty and uninformed of the risks of feeding fluids other than infant formula to their babies are particularly at risk.1 Young infants with vomiting and diarrhea are especially prone to developing hyponatremia if fed fluids lacking sufficient sodium, but even those who are otherwise well may develop symptomatic hyponatremia as a result of being fed excess solute-free water. Most often tap water, either in the form of supplemental feedings or overly dilute formula, has been given in excessive amounts over relatively short periods of time."
Careful reading of the paper by Bruce and Kliegman shows that they are talking about the effects of too much water
of any kind on the infant - they do not mention distilled water at all (solute-free seems to refer to water without formula, not water without ions), but they do mention an excess of tap water and later go on to state that the same problem can occur with feeding too much juice.
This kind of miss-interpretation of another paper's results is unfortunately fairly common with people digging through papers to find evidence to support their favorite idea. He does it again at the beginning of the section where he uses a paper that reports harmful effects of distilled water introduced directly into the small intestine - that has nothing to do with the effect of water, distilled or otherwise, that goes through the stomach first.
"A study by Williams (1963) reported that distilled water introduced into the intestine caused abnormal changes in epithelial cells of rats, possibly due to osmotic shock."
This is no doubt a true statement - any tissue exposed directly to
distilled water (or tap water for that matter), would experience osmotic
shock. This truth seems to be of limited relevance to the discussion
of the health effects of drinking distilled water.
A Brief discussion of the other main categories
in Kozisek's paper
2) Practically zero calcium and magnesium intake.
This section and the next talk about the epidemiological studies that seem to show populations drinking soft water tend to have more health issues, particularly heart problems, than those that drink hard water. As I mentioned above, the observation seems to be fairly repeatable (although many studies have not seen this difference), but the cause seems to be extremely elusive. These studies certainly do not prove that distilled water is harmful, if the diet supplies sufficient mineral nutrients.
3) Low intake of other essential elements and microelements.
"Although drinking water, with some rare exceptions, is not the major source of essential
elements for humans, its contribution may be important for several reasons. The modern diet of
many people may not be an adequate source of minerals and microelements. In the case of
borderline deficiency of a given element, even the relatively low intake of the element with
drinking water may play a relevant protective role. This is because the elements are usually
present in water as free ions and therefore, are more readily absorbed from water compared to
food where they are mostly bound to other substances."
As pointed out elsewhere, two liters of very hard water (the typical person consumes two litres of water per day) with 17 gpg of hardness will only contain about 232 milligrams (mg) of calcium. This is about 10 percent of a person's minimum daily requirement for calcium and would require a person to consume about 20 litres of water to meet their requirement by water alone. Most of a person's total dietary mineral intake comes from food
4) Loss of calcium, magnesium and other essential elements in prepared food.
I spotted one reference in the paper to support this section - I have not been able to find any others. I found
a copy of the article cited in Kozisek's paper. This is an interesting study, but I would like to see several more with some explanation of why the difference of a relatively few ions of calcium and magnesium in the water can cause the changes reported.
5) Possible increased dietary intake of toxic metals leached from water pipe.
This section may be true, but it has nothing to do with whether or not distilled water is inherently bad for health.
Softened water is NOT distilled water. Even so, I've read many
articles (by water softener companies mostly) that dispute this statement
stating that softened water is not solute free, calcium and magnesium
are just replaced by sodium (or potassium) and thus will not leach toxic
metals from pipes any more than hard water.
6) Possible bacterial re-growth
This section may be true too, but it has absolutely nothing to do with whether or not distilled water is inherently bad for
health based on lack of mineral content.
As I mentioned on my website I have searched in vain for good scientific papers that address this topic and provide a clear explanation of how small differences in ion content in water before it reaches the stomach can lead to drastic metabolic differences later
when it reaches the intestine. I have yet to find more than a couple of papers on the topic, much less a
Anyway, that's my two-cent contribution to the discussion. F. Kozisek may be associated with WHO, but I am not impressed with his analysis and conclusions
about distilled water.