This article has focused primarily on the relationship between dissolved hydrogen gas and the negative ORP value, rather than its therapeutic properties. However, because the negative ORP of H2 water is so often associated with the water's therapeutic or "antioxidant" properties, discussion of H2 as an antioxidant is warranted.
When comparing ORP readings of different water samples, it is commonly assumed that a more negative reading indicates higher antioxidant capacity and/or therapeutic benefit. Basic ionized water has higher levels of hydroxide (a negatively charged ion, OH-).
Some people, who may not be aware of the presence of H2, are now claiming that hydroxide is responsible for the negative ORP reading, even going so far as to identify it as an "antioxidant" in water (even though hydroxide is not a biological antioxidant) . Hopefully, the information contained in this and other articles will help dispel these and other myths about negative ORP and the source of therapeutic benefit.
We now know that the magnitude of the negative ORP measurement cannot be used to measure either the amount of dissolved H2 in the water or its therapeutic benefits.
Currently over 750 research studies show that the benefits of water containing dissolved H2 are due to the dissolved H2, not the pH. When H2 is removed from the water, the benefit is gone.
Given the many myths surrounding H2-containing water, we should ask, "Is there evidence that water containing dissolved H2 can actually act as an antioxidant in the body, or is this just another myth?"
What we do know is that there are now hundreds of research studies (in vitro, animal and human) that confirm the ability of H2 to reduce the concentration of some free radicals (particularly the very dangerous hydroxyl radical •OH) to reduce the level of oxidative stress to reduce. Therefore, based on research, it seems legitimate to call H2 an “antioxidant.”
However, because the thermodynamics of the scavenging reaction between H2 and the •OH radical are extremely unfavorable, some scientists were skeptical as to whether the reductions of free radicals observed in research were the result of direct radical quenching of •OH by H2.
It currently seems more likely that H2 acts as a free radical scavenger (conventional antioxidant) that it instead somehow reduces the formation of •OH radicals (the exact mechanism is still under investigation). While the end result is still an overall reduction in free radicals/oxidative stress, H2's role appears to be an indirect one, acting as a signal modulator to activate second messenger molecules (proteins/enzymes) which then facilitate the formation of Reduce free radicals.
It is therefore technically more correct to refer to this therapeutic property of H2 as “antioxidant-like”.
Excerpt from the book by Randy Sharpe: “The relationship between dissolved H2, pH and redox potential”
