World Health Organization paper on the risks of demineralized water with expert references: http://www.who.int/water_sanitation_health/dwq/nutdemineralized.pdf I don't have time to look at the current version this week but here is some info from http://ferrethealth.org/archive/FHL8423 >BEGIN QUOTE >Demineralised water is highly aggressive and if untreated, its >distribution through pipes and storage tanks would not be possible. >The aggressive water attacks the water distribution piping and leaches >metals and other materials from the pipes and associated plumbing >materials. > ... >Preliminary evidence was available that some substances present in >water could have beneficial effects on human health as well as adverse >effects... > END QUOTE and later in the paper: >BEGIN QUOTE >The possible health consequences of low mineral content water >consumption are discussed in the following categories: > >Direct effects on the intestinal mucous membrane, metabolism and >mineral homeostasis or other body functions. > >Practically zero calcium and magnesium intake. > >Low intake of other essential elements and microelements. > >Loss of calcium, magnesium and other essential elements in prepared >food. > >Possible increased dietary intake of toxic metals leached from water >pipe. > >Possible bacterial re-growth. >END QUOTE So, now to the sections that relate to the second list: BEGIN QUOTED SECTIONS which are trimmed and which contain my own words in brackets to avoid copyright violations. Please refer to original. >Distilled and low mineral content water (TDS < 50 mg/l) [is] >reported to be less thirst quenching (WHO 1980) > ... >Histology did not reveal any signs of erosion, ulceration or >inflammation... Altered secretory function in animals (i.e., increased >secretion and acidity of gastric juice) and altered stomach muscle >tone were reported in studies for WHO (1980) > ... >It has been adequately demonstrated that consuming water of low >mineral content has a negative effect on homeostasis mechanisms, >compromising the mineral and water metabolism in the body. An increase >in urine output (i.e., increased diuresis) is associated with an >increase in excretion of major intra- and extracellular ions from the >body fluids, their negative balance, and changes in body water levels >and functional activity of some body water management-dependent >hormones. >[Remember that much of cellular communication and other functions >require the right amount and balance of ions, no matter what the >charge (negative or positive). Robbing the body of needed ions can >be dangerous.] > ... >1) increased water intake, diuresis, extracellular fluid volume, and >serum concentrations of sodium (Na) and chloride (Cl) ions and their >increased elimination from the body, resulting in an overall negative >balance if it is not adequately compensated from food, and 2) lower >volumes of red cells and some other hematocrit changes (WHO 1980). >...[Decreased] secretion of tri- iodothyronine and aldosterone, >increased secretion of cortisol, morphological changes in the kidneys >including a more pronounced atrophy of glomeruli, and swollen vascular >endothelium limiting the blood flow. Reduced skeletal ossification was >also found [in when water low in minerals or lacking minerals was >consumed] > ... >Results of experiments in human volunteers evaluated by researchers >for the WHO report (1980) are in agreement with those reported in >animal experiments. Low-mineral water markedly: 1) increased diuresis >(almost by 20%, on average), body water volume, and serum sodium >concentrations, 2) decreased serum potassium concentration, and 3) >increased the elimination of sodium, potassium, chloride, calcium and >magnesium ions from the body. > ... >[The following section clearly described some of the ways that >distilled water consumption can be hazardous.] >The German Society for Nutrition reached similar conclusions, warning >the public against drinking distilled water (DgfE 1993). This warning >was published in response to the German edition of The Shocking Truth >About Water (Bragg and Bragg 1993), whose authors recommended drinking >distilled water instead of "ordinary" drinking water. The Society in >its position paper explains that water in the human body always >contains electrolytes (e.g. potassium and sodium) at certain >concentrations controlled by the body. Water resorption by the >intestinal epithelium is also enabled by sodium transport. If >distilled water is ingested, the intestine has to add electrolytes to >this water first, taking them from the body reserves. Since the body >never eliminates fluid in form of "pure" water but always together >with salts, adequate intake of electrolytes must be ensured. Ingestion >of distilled water leads to the dilution of the electrolytes dissolved >in the body water. Inadequate body water redistribution between >compartments may compromise the function of vital organs. Symptoms at >the very beginning of this condition include tiredness, weakness and >headache; more severe symptoms are muscular cramps and impaired heart >rate. > ... >Regular intake of low-mineral content water could be associated with >the progressive ...changes discussed above, possibly without >manifestation of symptoms or causal symptoms over the years. >Nevertheless, severe acute damage, such as hyponatremic shock >[water intoxication] or delirium, may occur following intense physical >efforts and ingestion of several litres of low-mineral water (Basnyat >et al. 2000). > ... >health problems were reported in mountain climbers who had prepared >their beverages with melted snow ...not supplemented with necessary >ions. 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 (CDC 1994). > ... >Although drinking water is not the major source of our calcium and >magnesium intake, the health significance of supplemental intake of >these elements from drinking water may outweigh its nutritional >contribution... diets not deficient in terms of the quantity of >calcium and magnesium, may not be able to fully compensate for the >absence of calcium and, in particular, magnesium, in drinking water. >[See also below section on how cooking with distilled water causes >losses from food.]... epidemiological studies in many countries... >have reported that soft water (i.e., water low in calcium and >magnesium) and water low in magnesium is associated with increased >morbidity and mortality from cardiovascular disease (CVD) compared >to hard water and water high in magnesium. > ... >Recent studies also suggest that the intake of soft water, i.e. water >low in calcium, may be associated with higher risk of fracture in >children (Verd Vallespir et al. 1992), certain neurodegenerative >diseases (Jacqmin et al. 1994), pre-term birth and low weight at birth >(Yang et al. 2002) and some types of cancer (Yang et al. 1997; Yang et >al. 1998). In addition to an increased risk of sudden death (Eisenberg >1992; Bernardi et al. 1995; Garzon and Eisenberg 1998), the intake of >water low in magnesium seems to be associated with a higher risk of >motor neuronal disease (Iwami et al. 1994), pregnancy disorders >(so-called preeclampsia) (Melles & Kiss 1992), and some types of >cancer (Yang et al. 1999a; Yang et al. 1999b; Yang et al. 1999c; >Yang et al. 2000). > ... >animals given water dosed with 5 mg/l of calcium exhibited >[impairment] in thyroidal and other associated functions compared to >the animals given the two higher doses of calcium. > ... >While the effects of most chemicals commonly found in drinking water >manifest themselves after long exposure, the effects of calcium and, >in particular, those of magnesium on the cardiovascular system are >believed to [be rapid] Only a few months exposure may be sufficient >[to cause health troubles] Illustrative of such short-term exposures >are cases in the Czech and Slovak populations who began using reverse >osmosis-based systems for final treatment of drinking water at their >home taps...Within several weeks or months various health complaints >suggestive of acute magnesium (and possibly calcium) deficiency were >reported (NIPH >2003). Among these complaints were cardiovascular disorders, >tiredness, weakness or muscular cramps. These are essentially the same >symptoms listed in the warning of the German Society for Nutrition. > ... >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 ...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. >Animal studies are also illustrative of the significance of >microquantities of some elements present in water. For instance, >Kondratyuk (1989) reported that a variation in the intake of >microelements was associated with up to six- fold differences in >their content in muscular tissue. > ... >Furthermore, a negative effect on the blood formation process was >found to be associated with non-supplemented demineralised water... >as much as 19% lower in the animals that received non-supplemented >demineralised water compared to that in animals given tap water. > ... >Recent epidemiological studies of an ecologic design among Russian >populations supplied with water varying in TDS suggest that low- >mineral drinking water may be a risk factor for hypertension and >coronary heart disease, gastric and duodenal ulcers, chronic >gastritis, goitre, pregnancy complications and several complications >in newborns and infants, including jaundice, anemia, fractures and >growth disorders (Mudryi 1999). > ... >The population of the area supplied with water lower in minerals >showed higher incidence rates of goiter, hypertension, ischemic heart >disease, gastric and duodenal ulcers, chronic gastritis, cholecystitis >and nephritis. Children living in this area exhibited slower physical >development and more growth abnormalities, pregnant women suffered >more frequently from edema and anemia. Newborns of this area showed >higher morbidity. > ... >When used for cooking, soft water was found to cause substantial >losses of all essential elements from food (vegetables, meat, >cereals). Such losses may reach up to 60 % for magnesium and calcium >or even more for some other microelements (e.g., copper 66 %, >manganese 70 %, cobalt 86 %). In contrast, when hard water is used for >cooking, the loss of these elements is much lower, and in some cases, >an even higher calcium content was reported in food as a result of >cooking (WHO 1978; Haring and Van Delft 1981; Oh et al. 1986; Durlach >1988). > ... >Low-mineralized water is unstable and therefore, highly aggressive to >materials with which it comes into contact. Such water more readily >absorbs metals and some organic substances from pipes, coatings, >storage tanks and containers, hose lines and fittings, being incapable >of forming low- absorbable complexes with some toxic substances and >thus reducing their negative effects > ... >Calcium and, to a lesser extent, magnesium in water and food are known >to have antitoxic activity. They can help prevent the absorption of >some toxic elements such as lead and cadmium from the intestine into >the blood, either via direct reaction leading to formation of an >unabsorbable compound or via competition for binding sites (Thompson >1970; Levander 1977; Oehme 1979; Hopps and Feder 1986; Nadeenko et al. >1987; Durlach et al. 1989; Plitman et al. 1989). > ... >The Czech National Institute of Public Health (NIPH, 2003) in Prague >has tested the safety of products intended for contact with drinking >water and found that the pressure tanks of the reverse osmosis units >are prone to bacterial re-growth. END QUOTED SECTIONS but there is a LOT more in there. [Posted in FML 6554]