Health Implications of Drinking High-Dissolved-Oxygen Water

Water with elevated dissolved oxygen (DO) — often marketed as “oxygenated water” or “oxygen-enriched water” — contains significantly more physically dissolved oxygen than ordinary tap water, which typically holds about 5–7 mg of oxygen per litre. While some commercial products claim health benefits from this extra oxygen, the scientific evidence tells a more nuanced story. 

Drinking water with excessively high DO levels does not confer meaningful physiological advantages and may, under certain circumstances, introduce undesirable effects.

Limited Physiological Absorption

The most fundamental point is that the human digestive system is not designed to absorb oxygen from water in any appreciable quantity. Unlike fish, which extract oxygen through their gills, humans obtain oxygen almost exclusively through respiration. Studies have shown that only a minuscule amount of oxygen can pass through the intestinal lining into the bloodstream. 

In fact, a single breath of air contains more oxygen (approximately 120 mL) than an entire bottle of oxygenated water (about 80 mL). Controlled trials have consistently failed to demonstrate that drinking oxygenated water raises blood oxygen levels, improves exercise performance, or accelerates recovery. From a physiological standpoint, the body simply does not rely on the gastrointestinal tract for oxygen uptake.

Potential for Oxidative Stress

A more substantive concern relates to the biochemical effects of increased oxygen concentrations. Elevated oxygen levels can lead to an increased production of reactive oxygen species (ROS) — highly reactive molecules that can damage cellular structures. If the body’s antioxidant defences are not fully efficient, ROS can cause cell injury, including DNA damage. 

One small study found that drinking oxygenated water led to a moderate generation of oxygen radicals, with concentrations increasing by 42% and remaining elevated for up to two hours after consumption. While the same study did not find evidence of genotoxic effects (i.e., permanent genetic damage), the transient increase in oxidative stress suggests that high-DO water is not entirely inert biologically.

Interference with Iron Absorption

Another potential concern involves mineral metabolism. Some sources suggest that long-term or excessive consumption of water with very high oxygen content may interfere with iron absorption, potentially contributing to anaemia over time. While the mechanism is not fully established, it is plausible that oxidative conditions in the gastrointestinal tract could affect the bioavailability of certain minerals. This effect would likely be relevant only with prolonged, heavy consumption rather than occasional intake.

Aesthetic and Palatability Issues

From a practical standpoint, water with excessively high dissolved oxygen often has an altered taste — described by some as slightly “sharp” or “tingling”. While this is not a health concern per se, it may affect consumer acceptance and hydration habits. Additionally, high DO levels can promote corrosion of metal pipes and fittings in water distribution systems, which, in turn, may lead to elevated concentrations of heavy metals such as lead, copper, or cadmium in drinking water — a genuine indirect health risk.