The terms "hydrogen water" and "electrolyzed reduced water" (ERW) are sometimes used interchangeably, but are distinct products with different properties. While both use electrolysis, ERW has been available for decades, but the beneficial properties result from dissolved molecular hydrogen ($H_2$), not the alkaline pH. Today's hydrogen water generators focus on maximizing $H_2$ concentration at a neutral pH.
The Role of Molecular Hydrogen
For decades, the benefits of electrolyzed water were attributed to its alkaline pH or other concepts. However, since 2007, research has shown that molecular hydrogen ($H_2$) is the therapeutic agent responsible for the antioxidant and anti-inflammatory effects of ERW. Molecular hydrogen is the smallest molecule, enabling it to penetrate cellular membranes and neutralize harmful reactive oxygen species (ROS).
This scientific breakthrough shifted the focus from high alkalinity to maximizing dissolved hydrogen concentration. Dedicated hydrogen water generators, using advanced technology like a Proton Exchange Membrane (PEM), infuse $H_2$ gas into water without altering its pH. This provides a higher, more consistent, and more bioavailable dose of the active ingredient.
Production Methods
The difference between hydrogen water and ERW lies in production and the chemical properties of the final product. ERW systems, or water ionizers, use electrolysis with electrodes separated by a membrane to create two streams: an alkaline, reduced water stream and an acidic, oxidized water stream. The alkaline stream, has a higher pH due to the concentration of hydroxide ions ($OH^−$) and minerals, but often a lower concentration of molecular hydrogen.
Modern hydrogen water devices prioritize a high concentration of dissolved $H_2$. These systems, including portable bottles and countertop units with advanced PEM technology, infuse water with hydrogen gas while keeping the pH neutral. This prevents the potential side effects associated with consuming high-pH water and ensures that the water's primary therapeutic component is delivered consistently. Another common method for generating hydrogen water is the use of magnesium tablets that react with water to produce $H_2$ gas.
Comparison: Hydrogen Water vs. ERW
| Feature | Hydrogen Water | Electrolyzed Reduced Water (ERW) |
|---|---|---|
| Goal | Infuse water with a high, stable concentration of dissolved molecular hydrogen ($H_2$). | Alter the water's pH to be highly alkaline, producing a side effect of dissolved hydrogen. |
| pH Level | Typically neutral (around 7) or near-neutral. | Significantly alkaline (e.g., pH 8.5–10.5 or higher). |
| Active Ingredient | Dissolved molecular hydrogen ($H_2$), a potent and selective antioxidant. | Molecular hydrogen ($H_2$) is the true active ingredient, but focus is often placed on alkalinity. |
| Technology | Modern electrolysis using PEM, or chemical reaction with magnesium tablets. | Older, separated electrolysis chambers that create both alkaline and acidic water streams. |
| H₂ Concentration | Generally higher and more consistent due to dedicated production methods. | Often lower and less stable. |
| Taste | Neutral and clean, identical to regular water. | May have a slightly mineralized or "slippery" feel due to the alkaline minerals. |
Health Implications
The health claims associated with ERW, such as neutralizing acidity in the body, are not supported by science. However, the antioxidant and anti-inflammatory properties of molecular hydrogen found in both types of water are supported by research.
Studies suggest molecular hydrogen may reduce oxidative stress, improve exercise performance, and offer anti-inflammatory effects. The evidence for dedicated hydrogen water is often stronger because it is designed for consistent delivery of the active agent, while the high pH of ERW can introduce other variables and potential safety concerns, such as interfering with stomach acid or leaching metals from electrodes.
Making an Informed Choice
Consumers should understand the distinction to make informed purchasing decisions. Those prioritizing the benefits of molecular hydrogen should seek dedicated hydrogen water generators that maximize $H_2$ concentration at a neutral pH. These devices offer a more targeted approach to reaping hydrogen's antioxidant and anti-inflammatory effects.
While ERW is a type of hydrogen-rich water, the older technology and emphasis on high pH can mean inconsistent therapeutic levels of $H_2$. Modern hydrogen water generators offer a simpler, more efficient, and scientifically aligned way to enjoy the benefits of molecular hydrogen.
Conclusion
Electrolyzed reduced water and hydrogen water both contain molecular hydrogen, but they are not the same. ERW machines prioritize high alkalinity, leading to lower and less stable hydrogen concentrations. Modern hydrogen water generators are designed to maximize dissolved molecular hydrogen at a neutral pH, offering a more consistent health benefit. Choosing a dedicated hydrogen water device is the best way to ensure a potent dose of the active therapeutic agent.
