What is Distilled Water?
Distilled water is a type of purified water that has been boiled until it evaporates. The water vapor is then condensed back into liquid form, leaving the water devoid of impurities.
At first glance this sounds great. However, “impurities” don’t just include the unwanted things in your water. The term covers a wide range of dissolved and suspended solids–from contaminants to minerals. While yes, we all want our water contaminant-free, the distillation process is non-discriminatory removal process that strips water of the good and the bad.
This leaves some arguing that as a suitable drinking water choice, distilled water leaves somethings to be desired.
Potential Health Risks of Drinking Distilled Water
According to the World Health Organization report, there are a handful possible negative effects that come with drinking demineralized (i.e. distilled) water–WHO claims it “might not be fully appropriate for consumption” because distilled water:
Can cause metals and other materials to leach from pipes and storage containers
It doesn’t taste as good as tap water
Can lead to low intake of essential elements and micronutrients
We’re going to breakdown these concerns below. The main point is this: while distilled water is better than contaminated water, it is not better than regular tap water and may even have negative health impacts.
Why does distilled water cause pipes and storage containers to leach undesirable contaminants?
If you store distilled water for drinking, you may be at risk of consuming parts of the container you store the water in. Because low- or demineralized water is molecularly unstable, it is “highly aggressive” to materials with which it contacts. Subsequently, distilled water can leach undesirable compounds from any material it comes in contact with.
Distilled water more readily dissolves plastics, (heavy) metals, and some organic substances from pipes, coatings, storage tanks and containers. As a result, you may wind up consuming them instead.
If you do drink distilled water, we recommend that you store it in glass.
Why does distilled water taste worse than regular tap water?
It is often reported that distilled water doesn’t taste as good as tap water. Some even claim it is less thirst quenching.
Why? Isn’t it just water?
When distilled water is created through the boiling process, the dissolved air within leaves the water. Subsequently, this results in a flat taste. Additionally, along with the loss of the dissolved air, calcium is also eliminated–which, when present, often contributes to water’s pleasant taste.
While neither flat taste nor lack of thirst-quenching are considered to be health effects, they could have some very real implications–as it may affect the amount of water one drinks.
How does distilled water impact nutrient intake?
While regular tap water is generally not a major source of nutrients, its contribution may be significant to your health–particularly when it comes to calcium and magnesium. As a World Health Organization (WHO) report notes, the typical modern diet may provide inadequate amounts of minerals and microelements. Subsequently, if faced with borderline deficiency of particular element, the relatively low intake of the element from drinking water may play a protective role in your health.
Elements in drinking water are usually present as free ions (rather than being bound to other substances when in food), making them more readily absorbed in the body.
In fact, the same WHO report goes on to discuss a handful of epidemiological studies from the past half century that indicate that water low in calcium and magnesium (also known as ‘soft water’) is associated with the following (when compared to hard water):
Increased morbidity and mortality from cardiovascular disease
A higher risk of fracture in children
Certain neurodegenerative diseases
Preterm birth and low weight at birth
What are the Uses of Distilled Water?
While we don’t typically recommend drinking distilled water, it certainly has its merits. Distilled water is often used for in laboratories for experiments, as well as for a variety of industrial applications. It is also a good choice for humidifiers, aquariums, and for use in cooling systems (as many many minerals found in tap water can damage lead-acid batteries).
What it Boils Down To
While we (generally) recommend drinking tap water over distilled water, this only holds true if you know what’s flowing from your tap. You should always test your water before making a definitive decision as to what is the best choice for you. If you find that you have low-quality or contaminated tap water, then distilled water is a better (and safer) choice