Why Don't We Want Pure Water? The Surprising Dangers of H₂O

November 14, 2025 •

3 min read

While pure water might seem like the healthiest choice, the World Health Organization (WHO) has warned against long-term consumption of demineralized water. In reality, we don't want pure water for drinking, cooking, or even certain industrial applications due to critical deficiencies and risks associated with its lack of dissolved minerals and ions.

Quick Summary

Pure water, such as distilled or deionized water, is not suitable for daily consumption because it lacks essential minerals and can disrupt the body's delicate electrolyte balance. This is in stark contrast to potable water, which is treated to remove harmful contaminants while retaining beneficial minerals.

Key Points

Electrolyte Disruption: Drinking large volumes of pure water can deplete the body's essential electrolytes, like sodium and potassium, leading to potentially dangerous health issues such as hyponatremia.
Essential Mineral Deficiency: Pure water lacks crucial minerals such as calcium and magnesium that are vital for bone density, cardiovascular health, and nervous system function, contributing to long-term health risks.
Flat, Unappealing Taste: The absence of dissolved minerals gives pure water a bland or flat taste, which may discourage adequate daily water intake.
Industrial and Lab-Specific Use: Pure water is not for daily consumption but is specifically produced for industrial processes, scientific experiments, and medical applications where impurities must be completely absent.
A 'Hungry' Solvent: As a powerful solvent, pure water is "hungry" for minerals and will readily leach them from whatever it contacts, including your body's cells and plumbing.
The Healthiest Water is Balanced: The healthiest drinking water is not the 'purest' but is potable water, which is treated to remove harmful contaminants while retaining beneficial minerals.

The Flawed Logic of 'Pure is Better' for Your Body

The idea that 'purer' is always better for health is a pervasive myth, particularly regarding water. When we talk about "pure water" in a scientific context, we mean water that has had virtually all minerals, ions, and impurities removed. This is a stark contrast to the potable drinking water that we are accustomed to. While purifying water to remove harmful bacteria and chemicals is essential, over-purification that removes all beneficial components creates a substance that is not only unappealing but potentially hazardous to consume over time.

Why the Body Craves Impurities (The Good Kind)

Our bodies rely on a balanced intake of electrolytes—minerals like sodium, potassium, and magnesium—to function correctly. Normal tap and mineral water contain these vital substances. Pure water, devoid of these minerals, can act as a solvent, aggressively attempting to restore its equilibrium by pulling minerals from the body's cells. This process is known as osmosis. When we drink large quantities of pure water, it can dilute the electrolytes in our blood, leading to a dangerous condition called hyponatremia. This can cause headaches, fatigue, and, in extreme cases, more severe neurological problems.

It's All in the Taste—or Lack Thereof

Beyond the health implications, pure water simply lacks a palatable taste. The taste we associate with water comes from the dissolved minerals and gases it contains. Without them, the flavor is often described as flat or bland, making it less appealing for daily hydration. Water's flavor is a composite of taste and smell, and the absence of impurities leaves it tasting slightly sour. While a subtle difference at first, relying on it for all hydration can make it less likely for you to drink enough water throughout the day.

Pure Water is a Tool, Not a Beverage

Pure water serves a crucial purpose, but it is confined primarily to industrial and laboratory settings where impurities could compromise processes or results. These applications demonstrate why removing all minerals is necessary for specific, non-consumptive tasks. Its specific chemical properties, including its high electrical resistance and solvency, are assets in these controlled environments.

Laboratory applications: Scientists use ultrapure water (Type I) for highly sensitive experiments like High-Performance Liquid Chromatography (HPLC), cell and tissue culture, and molecular biology to prevent contamination and ensure reproducible results.
Industrial manufacturing: The electronics and semiconductor industries rely on ultrapure water (UPW) to produce microchips and LCD panels, as even trace impurities can cause defects.
Equipment operation: Distilled or deionized water is used in steam irons, car batteries, and PC water cooling systems to prevent mineral buildup and corrosion.
Pharmaceutical production: High-purity water is essential for creating Water For Injection (WFI) and other medical applications to meet strict safety and quality standards.

A Comparative Look: Pure Water vs. Potable Water


Feature	Pure Water (Distilled/Deionized)	Potable Water (Tap/Mineral)
Mineral Content	Virtually zero. Essential minerals are removed.	Contains essential minerals like calcium, magnesium, and potassium.
Health Impact	Long-term consumption can lead to mineral deficiencies and electrolyte imbalances.	Contributes to overall health by supplying vital minerals and electrolytes.
Taste	Flat, bland, or slightly strange due to the absence of dissolved solids.	Varies based on mineral composition, giving it a familiar and often pleasant taste.
Primary Use	Scientific laboratories, industrial processes, medical devices.	Daily human consumption, cooking, and sanitation.
Regulation	Not regulated by drinking water standards unless specifically processed and bottled for consumption.	Highly regulated by health authorities to ensure safety for public drinking.

Conclusion: The Right Water for the Right Job

In summary, the notion that pure water is the ideal drinking choice is a fundamental misunderstanding of our biological needs. The dissolved minerals in potable water are not impurities to be removed, but rather vital nutrients that support our health. While high-purity water is indispensable for specific scientific and industrial applications, drinking it over time can cause mineral deficiencies and disrupt the body's essential functions. We don't want pure water for daily hydration because our bodies are evolved to thrive on the very "impurities" that give water its taste and nutritional value. The best water for us is clean, safe, and rich with the minerals nature intended us to consume. It is a matter of fitness for purpose, and in the case of drinking water, purity is not a virtue but a deficit.

Optional Outbound Link: Learn more about the World Health Organization's report on demineralized water and its health implications.

Frequently Asked Questions

While drinking a glass of distilled water is not immediately dangerous, substituting it for your regular drinking water over a long period can be harmful. It is devoid of minerals and could lead to deficiencies if your diet doesn't compensate for the loss.

Pure water often tastes flat or bland because the flavor we perceive in water comes from dissolved minerals and gases. Without these impurities, the water lacks its familiar taste profile.

Yes, long-term consumption of pure, demineralized water can lead to mineral deficiencies, particularly of calcium and magnesium, which are important for bone health and proper bodily function.

Hyponatremia is a condition where low sodium levels in the blood cause cells to swell. Drinking excessive amounts of pure water can dilute the body's electrolytes, including sodium, triggering this dangerous state.

The primary difference is the presence of minerals. Pure water has virtually all minerals and ions removed, while potable drinking water is treated to remove harmful contaminants but retains beneficial minerals and electrolytes.

Pure water is crucial for scientific experiments where impurities could skew results, in industrial settings like electronics manufacturing to prevent defects, and in devices like car batteries and humidifiers to prevent mineral buildup.

Yes, tap water from municipal sources typically contains essential minerals like calcium, magnesium, and potassium, which are beneficial to human health.