Health Effects of Drinking Demineralized Water

Although mankind has been successfully drinking water with little or no minerals for thousands of years, some people insist that this type of water will leach minerals from the body.  The mineral content of water can vary widely from brackish water to water with little or no minerals. Water found in lakes and streams is often very low in mineral content because it remains on the surface rather than traveling through the ground to an aquifer.   Many large populations regularly consume water with little or no minerals ...

• The cavemen probably figured out how to collect rain water.
• Distilled water was being made in the days of Julius Caesar.
• Our armed forces are often supplied with water that has been processed through a reverse osmosis system.
• Personnel on submarines and at NASA utilize water from distillers and deionizers.
• Many cities (Seattle, Portland) supply their citizens with water from snow melt that is very low in mineral content.

If drinking water with little or no minerals produced a health hazard, there should be clear evidence of this in the populations exposed to this type of water.   There is no report of wide spread health problems related to drinking low mineral content water among the military, astronauts and citizens that get their water from snow water run off.  When these populations are getting sufficient mineral intake from their food, the mineral content of the water doesn't matter.

Despite clear evidence to the contrary, there are people that argue that there should be a minimum amount of minerals in the water to avoid negative health effects.  This argument seems to be based in a very strong cultural bias.  For centuries, Europe has promoted its health spas for the benefits of their mineral water for bathing and drinking.  The commercial interests promote the bias in the sales of bottled waters from "special" sources.  Makers of simple water filters that cannot remove minerals, spin this limitation into a benefit by claiming it "leaves the healthy minerals in the water."

Many proponents of mineral water refer back to an old Russian study that claimed that the absence of minerals in the water caused health problems.  However
Rozelle describes the Russian studies as "short on data and long on deductions leading to there conclusions."¹ p 8   We have not found any references to the study that discusses the diet of the test subjects, which would be an important source of minerals.

More recently the World Health Organization (W.H.O.) recommended minimum standards for mineral content of drinking water.  However this was primarily motivated by the concern for water contamination caused by corrosion of plumbing.  To supply water for growing cities, desalinization plants are used to convert salt water into drinking water.  This water contains very few minerals and can cause corrosion when in contact with a metal distribution system (plumbing). The corrosion of the pipes adds contaminants to the water.  When providing water for a city, it does make good sense to add some minerals to the water to have better corrosion control.  But this proposed health risk should not apply to low mineral water that is not subject to long exposure to metal plumbing.  If there is no corrosion, there is no added contamination.  It is entirely plausible that any health effects seen in the Russian Study was due to the fact that the people drinking hard water (high mineral content) were protected from contamination due to corrosion, because hard water is not corrosive to pipes. 

The human body is an incredible organism capable of maintaining mineral concentrations within proper parameters regardless of the mineral content of the water consumed.  If the mineral concentration in the bodily fluids drops below an acceptable level, the kidneys reabsorb needed minerals and excrete more water.  If the mineral concentration is too high, the kidneys release minerals and reabsorb the needed water.  This is how the body maintains homeostasis.   This balance of mineral concentration in the body can be upset when the person loses lots of water and minerals due to heavy perspiration.  This may occur in hot, humid weather or during extreme physical exercise.  In this case it is important to be sure that the body’s supply of water is replenished along with necessary minerals.  This is why athletes use sport drinks to help keep their electrolytes (minerals) in proper balance as well as to hydrate the body.  But during normal day to day activities for most people it really makes no difference if the water contains minerals or not.  Keeping hydrated with water is critical.  But the more reliable source for minerals is the food we eat.

Some studies have shown that people living in areas with high levels of magnesium in the water are at lower risk of cardiovascular disease (CVD). Although a cause and effect link seems to be present, it cannot be considered a determinant because of the multiple factors that come into play regarding the etiology of CVD.  In many cities, even drinking tap water may not provide the protective effect one is looking for.  The fact remains that the most reliable source for minerals is in the food we eat.  But if one’s diet is lacking the proper nutrients, taking a mineral supplement is an easy way of getting the minerals one needs in the proper concentrations.   So, if your doctor is recommending mineral supplementation, but you just don’t like swallowing pills, minerals can be added to the water in the form of drops or a remineralizing filter can be added to an existing filter or simply used to add minerals to tap water.  However, the fact remains, the best source for minerals is in the food we eat.

References:

1. Lee T Rozelle; Potential Human Health Effects due to Consumption of High Purity Water: Highlight Investigation; Presented at Annual Water Quality Association Conf. March 1993.
   
2. Lee T Rozelle; “All in the body’s Balance – Ill health effects are not connected to consumption of low TDS water;”  Water Technology March 1997, pp 126-132.
   
3. Kozisek, Frantisek;  “Health Risks from Drinking Demineralised Water”; National Institute of Public Health, Czech Republic.  Chapter 12 in Water, Sanitation and Health Protection and the Human Environment; W.H.O., Geneva; 2005, http://www.who.int/water_sanitation_health/dwq/nutrientsindw.pdf (accessed 9/11/10)
   
4. S Monarca, Donato, Zerbini, Caldereon, Craun; “Review of Epidemiological Studies on Drinking Water Hardness and Cardiovascular Diseases”. Eu J Cardiovasc Prev Rehabil.2006 Aug;13(4):495-506, http://www.ncbi.nlm.nig.gov/pubmed/16874137 (accessed 9/11/10)
   
5. S Monarca, Zerbini, Simonati, Gelatti; “Drinking Water Hardness and Chronic Degenerative Diseases. II. Cardiovascular Diseases”.  Ann lg.2003 Jan-Feb;12(1):41-56.  Article in Italian. http://www.ncbi.n.m.nih.gov/pubmed/12666324 Abstract in English (accessed 9/11/10)
   
6. RW Morris, Walker, Lennon, Shapere, Whinccup; “Hard Drinking Water Does Not Protect Against Cardiovascular Disease: New Evidence from the British Regional Heart Study”.Eur J. Cardiovasc Prev Rehabil. 2008 Apr: 15(2):185-9. http://www.ncbi.nlm.nh.gov/pubmed/18391646 (accessed 9/11/10)