What is Alkaline Water?
Alkaline describes any substance that has a pH greater than 7. In the context of drinking water, naturally alkaline water occurs when water passes over or filters through rocks, like springs rich in limestone and chalk. As the water flows, it picks up and dissolves essential minerals such as calcium, magnesium, and potassium, which increase its pH level. This mineral composition is what makes the water naturally basic.
How natural alkalinity is created
The process for creating naturally alkaline water is straightforward and relies on geological interactions. The water's long-term exposure to certain rocks and mineral deposits allows for the slow and continuous dissolution of alkaline compounds. This process results in a stable alkaline water with a balanced mineral profile.
Artificially created alkaline water
Water can also be made artificially alkaline by adding alkaline mineral compounds, such as baking soda (sodium bicarbonate), calcium, or magnesium. This method is commonly used in bottled alkaline water products to raise the pH to the desired level. While effective at raising the pH, this method does not typically result in the same properties as water created through electrolysis.
What is Alkalized Water?
Alkalized water refers to water that has been made alkaline through a specific, manufactured electrical process called electrolysis. It is often sold as "alkaline ionized water" or "electrolyzed reduced water". During electrolysis, a machine called a water ionizer uses an electric current to split water molecules ($H_2O$) into separate acidic and alkaline streams. The machine then separates the negatively charged hydroxide ions ($OH^−$) from the positively charged hydrogen ions ($H^+$).
The process of electrolysis
- Filtration: Tap water first passes through a filtration system to remove impurities and contaminants.
- Ionization: The filtered water enters an ionization chamber where it is exposed to an electrical current, separated by a membrane.
- Separation: The process separates the water into two streams: one rich in hydroxide ions (the alkaline water) and the other rich in hydrogen ions (the acidic water).
- Collection: The alkaline water stream, typically with a pH of 8 or 9, is collected for drinking.
Key characteristics of alkalized water
- Antioxidant potential: Alkalized water, especially when fresh from the ionizer, can have a negative oxidation-reduction potential (ORP), giving it antioxidant properties. This effect is temporary and decreases over time.
- Molecular hydrogen: The electrolysis process also produces molecular hydrogen ($H_2$), which some proponents link to health benefits, though more research is needed.
- Instability: Unlike naturally occurring alkaline water with stable mineral content, the antioxidant properties of ionized water are temporary, lasting only about 24 hours.
Alkaline vs. Alkalized: A Direct Comparison
| Feature | Naturally Alkaline Water | Artificially Alkalized (Ionized) Water |
|---|---|---|
| Source of Alkalinity | Dissolved alkaline minerals from geological sources. | An electrical process called electrolysis. |
| Process | Natural geological filtration over mineral deposits. | Manufactured ionization using an electrical current. |
| Stability | Stable pH and mineral content. | The beneficial antioxidant properties are temporary and decrease over time, often within 24 hours. |
| Mineral Content | Naturally rich in essential minerals like calcium, magnesium, and potassium. | Variable; depends on the mineral content of the source water. Some ionizers may add minerals back, while others do not. |
| Additional Properties | None beyond mineral enrichment. | Can contain molecular hydrogen and have a negative ORP (antioxidant potential). |
Health Claims and Considerations
Many health claims surround alkaline and alkalized water, though scientific evidence varies.
Potential benefits (some require more research)
- Hydration: Some studies suggest that ionized alkaline water may offer more effective hydration due to its smaller molecular clusters.
- Acid Reflux Relief: The higher pH may help neutralize stomach acid and alleviate symptoms of acid reflux.
- Antioxidant Support: Alkalized water’s negative ORP has been promoted for its ability to neutralize free radicals, though the effect is temporary.
Potential Risks
- Kidney Concerns: Individuals with kidney problems should be cautious about drinking high-pH water, especially ionized water with a very high pH (above 9.8), due to the risk of hyperkalemia (high potassium levels).
- Misleading Claims: Many marketing claims about curing diseases like cancer lack scientific backing. The body has a natural buffer system to maintain a stable blood pH, which is not significantly altered by diet.
Conclusion: Which is Right for You?
When considering the difference between alkaline and alkalized water, the core distinction is the method of production. Natural alkaline water gets its higher pH from a stable mineral content, while artificially alkalized water uses an electrical process (electrolysis) to create a temporary, high-pH state with antioxidant properties. Natural alkaline water is a simple, mineral-rich option, while alkalized (ionized) water offers a temporary antioxidant boost but is more expensive and has less scientific support for its purported health benefits. For most people, either option is safe, but those with health conditions should consult a doctor before making a major dietary change. Choosing the right water for you depends on your budget, health goals, and preference for natural versus technologically enhanced products. For a deeper scientific explanation of molecular hydrogen and its role, consult the Molecular Hydrogen Institute.
