What is Distilled Water?
Distilled water is created through a process of boiling and condensation. The water is heated until it turns into steam, leaving behind minerals, sediments, heavy metals, and most other impurities. The steam is then collected and cooled, condensing back into a liquid form that is exceptionally pure but also stripped of everything else. While this process makes it ideal for industrial, laboratory, and medical applications where mineral buildup is undesirable, it also removes the beneficial minerals that are present in regular drinking water, like tap, spring, and purified water.
The Distillation Process
During distillation, tap water is brought to a boil, converting it into steam. This steam rises, leaving behind virtually all solid and inorganic compounds, including beneficial minerals such as calcium, magnesium, and potassium, as well as contaminants. The steam then travels into a separate chamber, where it is cooled and condensed back into its liquid state. The resulting water is highly pure, containing only hydrogen and oxygen molecules, which is why its taste is often described as bland or flat. The entire process is essentially a way of mimicking the natural water cycle in a controlled environment, isolating pure water from its impurities.
The Primary Reason: A Lack of Minerals
The most significant health concern surrounding regular consumption of distilled water is its complete lack of dissolved minerals and electrolytes. The World Health Organization (WHO) has raised concerns about the potential adverse effects of drinking demineralized water over the long term. While most of our mineral intake comes from a balanced diet, water is a supplemental source, and relying solely on demineralized water can contribute to deficiencies over time.
Electrolyte Imbalance and Hydration
Electrolytes, such as sodium, potassium, and chloride, are crucial for proper bodily function, including nerve signaling, muscle contraction, and maintaining proper hydration. Since distilled water contains no electrolytes, consuming large quantities can disrupt the body's delicate electrolyte balance, especially during periods of heavy sweating or physical exertion. While a person with an average, healthy diet is unlikely to be severely impacted, it is not recommended for athletes or individuals who lose electrolytes quickly.
Demineralized Water's "Aggressive" Nature
According to research highlighted by the WHO, demineralized water is more "aggressive" or reactive. Because it lacks dissolved minerals, it can actively pull minerals from whatever it contacts to achieve balance, including from the body's tissues and the storage containers it is kept in. In the body, this has led to concerns about potential mineral leaching from teeth and bones, potentially contributing to conditions like dental cavities and osteoporosis over a long period. Additionally, storing distilled water in certain plastic containers may cause the plastic to leach unwanted chemicals into the water.
The Hidden Drawbacks of Regular Consumption
Beyond mineral deficiency, drinking distilled water regularly has other notable downsides.
- Flat, Unappealing Taste: The minerals in tap or spring water contribute significantly to its taste profile. Without them, distilled water tastes distinctly bland or flat, which can discourage some people from drinking enough water and may lead to reduced overall hydration.
- Impact on Dental Health: Many municipal water systems add fluoride to tap water to prevent tooth decay. The distillation process removes this fluoride, which is a consideration for dental health, particularly in children.
- Potential for Recontamination: While initially pure, distilled water has a unique ability to absorb substances from its environment, including carbon dioxide from the air. This can cause its pH to become slightly acidic over time. Its "aggressive" nature also makes it more susceptible to recontamination if not stored properly in a sealed, high-quality container.
Distilled Water vs. Other Types of Water
To better understand why distilled water isn't ideal for everyday drinking, it's helpful to compare it to other common water types.
| Feature | Distilled Water | Tap Water | Purified Water | Spring Water |
|---|---|---|---|---|
| Mineral Content | Virtually none | Variable, typically moderate | Very low to low | Moderate, naturally occurring |
| Purification Method | Boiling and condensation | Filtration and chemical disinfection | Reverse osmosis, deionization, etc. | Natural filtration through rock |
| Contaminants Removed | Most all | EPA-regulated contaminants | Most chemicals and microbes | Variable, depending on source |
| Taste | Flat, bland | Variable, depends on source and additives | Generally clean | Crisp, fresh |
| Primary Use | Appliances, medical, industrial | Drinking, cooking, washing | Drinking, specific industrial use | Drinking |
| Long-Term Health | Not recommended | Generally safe (with good tap quality) | Safe, some mineral loss | Generally safe, beneficial minerals |
When is Distilled Water Appropriate?
While unsuitable for regular consumption, distilled water has specific, beneficial applications where its purity is required. These uses include:
- Home Appliances: Using distilled water in steam irons, humidifiers, and car batteries prevents mineral buildup and scaling that can damage the equipment.
- Medical Devices: It is often recommended for use in Continuous Positive Airway Pressure (CPAP) machines to prevent mineral deposits from forming.
- Laboratory and Medical Use: In laboratory settings, its purity is essential for experiments and tests. It's also used for cleaning and sterilizing medical equipment.
How to Ensure Healthy Hydration
For daily hydration, healthier and more palatable alternatives are readily available. If you are concerned about contaminants in your tap water, consider investing in a water filter that removes harmful substances while retaining beneficial minerals. Filtered water systems, such as pitchers or under-sink filters, offer a good balance of purity and nutritional content. Alternatively, drinking bottled spring water provides natural minerals and a pleasant taste. The key is to choose a water source that meets your purity needs without sacrificing the essential minerals your body requires for optimal function.
Conclusion
While distilled water is the purest form of water available, its lack of essential minerals and electrolytes makes it an unsuitable choice for regular, long-term consumption. The potential risks of mineral deficiency, electrolyte imbalance, and a less-than-ideal taste outweigh its benefits for daily hydration. Distilled water serves a specific purpose in medical and industrial applications where purity is paramount. For a balanced, healthy approach to drinking water, opt for tap, purified, or spring water, and ensure your diet provides a sufficient amount of essential minerals. Your body will thank you for it.
For more information on distilled water's properties, you can consult WebMD's detailed overview of the topic.
