What is Demineralized Water?
Demineralized water is water that has undergone a process to remove most of its mineral content. This can be achieved through several methods, including deionization, reverse osmosis (RO), and distillation. The end product is water that is nearly free of dissolved inorganic mineral salts and metals, but it may still contain other contaminants such as bacteria, viruses, or organic impurities depending on the purification process used. For many industrial, laboratory, and technical applications, this purity is essential to prevent mineral buildup and contamination. However, its use for regular human consumption is a different matter.
The Aggressive Nature of Demineralized Water
One of the main characteristics of demineralized water is its aggressive nature. Without a high concentration of dissolved minerals, the water becomes a more powerful solvent. This means it will actively seek to dissolve and absorb substances it comes into contact with to reach a state of balance. When consumed, this can have several effects:
- Leaching of minerals: Demineralized water can leach minerals from materials, including the pipes and containers it is transported or stored in. This can result in the reintroduction of potentially toxic metals like lead into the water.
- Loss of minerals from food: Cooking food in demineralized water can significantly reduce its mineral content. Studies have shown that boiling vegetables in soft water can lead to substantial losses of calcium and magnesium.
- Electrolyte imbalance in the body: The World Health Organization (WHO) and other research bodies have reported that drinking water with a low mineral content compromises the body's mineral and water metabolism. The intestinal tract, in an attempt to balance the electrolytes, will pull them from the body's reserves, potentially leading to an electrolyte imbalance.
Health Risks of Drinking Demineralized Water Long-Term
While short-term or occasional consumption is unlikely to cause immediate harm for most healthy individuals, prolonged or exclusive use of demineralized water has been linked to a number of adverse health effects. These are primarily due to the lack of essential minerals that contribute to bodily functions.
Potential health consequences include:
- Mineral Deficiency: Demineralized water lacks calcium and magnesium, which are vital for bone health, muscle function, and cardiovascular health. Long-term deficiency can contribute to conditions like osteoporosis and higher risks of fractures.
- Electrolyte Dysregulation: A sustained intake of low-mineral water can alter the body's water-salt balance. This can increase diuresis (urine output), leading to increased excretion of essential ions like sodium, potassium, and chloride. Early symptoms may include tiredness, weakness, and headaches, while more severe cases can result in muscular cramps or irregular heartbeats.
- Increased Diuresis: Studies conducted by the WHO have shown that human volunteers drinking low-mineral water experienced a nearly 20% increase in diuresis, an enhanced body water volume, and serum sodium concentrations.
- Cardiovascular Disease Risk: Epidemiological studies have found an association between drinking soft water (low in calcium and magnesium) and increased morbidity and mortality from cardiovascular diseases. While water is not the primary source of these minerals, its consistent intake can supplement dietary sources.
- Pregnancy and Newborn Complications: Some studies suggest an association between water low in calcium and magnesium and a higher risk of complications during pregnancy, such as preeclampsia, preterm birth, and low birth weight.
- Unfavorable Taste and Hydration: The absence of minerals gives demineralized water a flat, unappealing taste, which might reduce overall water intake and negatively affect hydration levels.
- Increased Intake of Toxic Metals: As mentioned, the corrosive nature of demineralized water can cause it to leach metals like lead from plumbing materials, increasing the risk of ingesting harmful contaminants.
Demineralized vs. Distilled Water: Are They the Same for Your Health?
While often used interchangeably, there are key differences between demineralized (DI) and distilled water that impact health considerations.
| Feature | Demineralized Water | Distilled Water |
|---|---|---|
| Purification Method | Ion exchange or reverse osmosis (RO). | Boiling water into steam and then condensing it back into liquid. |
| Impurities Removed | Primarily removes mineral ions (salts). | Removes minerals, bacteria, viruses, and most organic compounds. |
| Contaminants Remaining | Can leave behind uncharged contaminants like bacteria, viruses, and volatile organic compounds (VOCs). | Can still contain some VOCs that vaporize at or below water's boiling point, though these can be addressed with additional filtering. |
| Health Risk Factors | Primarily linked to mineral deficiency and electrolyte imbalance from lack of minerals. Also potential for microbial contaminants if not further filtered. | Primary risk is also mineral and electrolyte deficiency. The process is more effective at removing microbes than standard deionization. |
| Safety for Drinking | Considered safe in emergency situations, but not recommended for regular, long-term consumption due to mineral stripping and potential contaminants. | Safe to drink, but not recommended as a primary source of hydration for the same reasons as DI water (mineral deficiency). |
Conclusion
While a single glass of demineralized water won't harm a healthy person, the long-term, exclusive consumption of water devoid of minerals is not advisable. For most individuals, the bulk of essential minerals comes from their diet, but the supplemental intake from drinking water, especially for critical minerals like calcium and magnesium, should not be overlooked. The risks of long-term consumption include electrolyte imbalance, nutrient loss from cooked food, and potential cardiovascular issues. For daily hydration, it's safer and more beneficial to consume water with a balanced mineral content. If you are concerned about contaminants in your water supply, investing in a reputable water filtration system, such as one with reverse osmosis, can purify your water while also providing a remineralization option to ensure your body receives essential nutrients. Ultimately, the best water for regular drinking is clean, safe, and contains a healthy balance of minerals.
The importance of proper hydration is widely accepted, but the composition of that hydration matters greatly. For a deeper scientific dive into the effects of demineralized water on the body, consider exploring research and guidelines published by the World Health Organization.
