Distilled water is created through a process of boiling water to produce steam, which is then condensed back into a liquid state, leaving behind minerals and impurities. While this process results in exceptionally pure water, it also removes everything else, including beneficial minerals. For this reason, evaluating the upsides and drawbacks is essential for anyone considering it as a regular part of their diet.
The Pros of Drinking Distilled Water
Distilled water's primary advantage lies in its purity, making it a safe choice in specific circumstances.
- Removes Contaminants: The distillation process is highly effective at removing a wide array of contaminants, including bacteria, viruses, pesticides, and heavy metals like lead. This makes it a safer option than tap water in areas with contaminated water supplies.
- Free from Additives: Unlike municipal tap water, distilled water contains no added chemicals, such as chlorine or fluoride, which can be a concern for some individuals.
- Good for Detoxification (Short-Term): Some advocates believe that drinking pure water can aid the body in a short-term cleanse or detox, helping to flush out impurities without introducing new ones.
- Ideal for Medical and Home Equipment: The complete lack of minerals prevents the buildup of mineral scale (limestone) in household appliances like steam irons and humidifiers, as well as in critical medical devices like CPAP machines.
- No Unwanted Tastes: For those who dislike the taste of chlorine or other minerals in tap water, distilled water offers a neutral, unflavored option for brewing coffee, tea, or cooking.
The Cons and Risks of Drinking Distilled Water
While its purity can be a benefit, the lack of minerals presents the most significant drawbacks for regular consumption.
- Lack of Essential Minerals: The distillation process removes all beneficial minerals, including calcium, magnesium, and potassium, which are important for bone health, metabolic function, and electrolyte balance. While our primary mineral intake comes from food, water also contributes, and exclusive consumption of distilled water can lead to deficiencies if diet is not carefully managed.
- Flat, Bland Taste: The minerals in water contribute to its flavor profile. Without them, distilled water often tastes flat or bland, which may lead some people to drink less water and become under-hydrated.
- Potential for Electrolyte Imbalance: Intense physical activity, prolonged illness, or fasting can deplete the body's electrolytes. Drinking only distilled water cannot replenish these lost electrolytes, which can lead to symptoms like fatigue, muscle cramps, and headaches.
- Slightly Acidic: When exposed to air, distilled water absorbs carbon dioxide, which creates a weak carbonic acid and lowers the water's pH. This slight acidity is not generally considered harmful, as beverages like coffee and juice are far more acidic, but it is a noticeable change from neutral tap water.
- May Not Remove All Contaminants: While effective against many impurities, distillation is not perfect. Volatile organic compounds (VOCs) and pesticides that have a boiling point lower than or similar to water may evaporate and re-condense with the steam, contaminating the final product.
Distilled Water vs. Other Water Types
| Feature | Distilled Water | Tap Water | Reverse Osmosis (RO) Water |
|---|---|---|---|
| Purification Method | Boiling and re-condensing steam | Municipal filtration and chemical treatment | Pressure filtration through a semi-permeable membrane |
| Purity Level | Extremely pure (99.9%+) | Varies by location; regulated but may contain trace contaminants and minerals | Very high purity, but may retain or have minerals added back |
| Mineral Content | Virtually none | Varies; contains beneficial minerals and electrolytes | Can have low or high mineral content depending on the system |
| Taste | Often described as flat or bland | Varies greatly based on local source and mineral content | Generally clean and balanced, especially if minerals are re-added |
| Best For | Short-term use, appliances, medical equipment | Everyday drinking for most people with good municipal supply | Everyday drinking for higher purity with better taste and mineral balance |
Long-Term Health Considerations
For healthy individuals with a balanced and mineral-rich diet, drinking distilled water in moderation is generally not harmful. The human body obtains the vast majority of its essential minerals from food, not water. However, relying exclusively on distilled water as your only hydration source for an extended period is not advisable.
Certain groups should be more cautious. Athletes who lose significant electrolytes through sweat, or individuals with pre-existing conditions that affect mineral balance (e.g., kidney disease, malnutrition, malabsorption syndromes) should avoid relying on distilled water. The potential risks associated with long-term, exclusive consumption—particularly electrolyte imbalance and mineral deficiency—are serious enough that a more balanced hydration source is recommended for most people. The World Health Organization (WHO) has noted potential adverse health effects related to demineralized water consumption.
Conclusion
Drinking distilled water offers a clear benefit in terms of purity, making it a safe choice in areas with poor water quality or for use in sensitive equipment where mineral buildup is an issue. However, for everyday, long-term hydration, the drawbacks—particularly the absence of essential minerals and the potential for a flat taste—make it less ideal than other options for most healthy adults. While it won't harm you in the short term, ensuring adequate mineral intake through a balanced diet is crucial if you choose to consume it regularly. For most, opting for tap water (in regulated areas) or other purified options that retain or re-add minerals provides the best balance of safety and nutritional benefits.
More information can be found in the WHO's guidelines on drinking water quality.
