Hydrogen, the selective antioxidant that Nature Medicine put on the map

In 2007, an article published in the scientific journal Nature Medicine caught the attention of the medical and scientific world: “
Hydrogen acts as a therapeutic antioxidant by selectively reducing cytotoxic oxygen radicals” (Ohsawa et al., 2007). Nature

Since then, molecular hydrogen (H₂) has been studied as a very special antioxidant – capable of reducing some of the most aggressive free radicals without “erasing” the body’s beneficial signals. Wikipedia

In this article, we will explain, in simple language:

  • What this Nature Medicine study really showed

  • Why hydrogen is different from other antioxidants

  • How this relates to hydrogen-rich water and hydration habits

  • And how you can, if you wish, try ionised, hydrogen-rich water with Aquapure

1. The underlying problem: oxidative stress and free radicals

Every day, our bodies produce reactive oxygen species (ROS) – the famous “free radicals”. They are not all villains: some are essential for:

  • Cell signalling

  • Immune defence

  • Response to infections

The problem begins when there is an excess of free radicals (chronic oxidative stress). This is associated with:

  • Cardiovascular disease

  • Type 2 diabetes

  • Neurodegeneration

  • Chronic inflammatory processes

Traditionally, the response has been: “take antioxidants” (vitamin C, E, polyphenols, etc.). But many clinical trials with classic antioxidants have had disappointing results because, by neutralising everything, they can also interfere with normal physiological processes.

Something smarter was needed – a selective antioxidant.

2. What did the Nature Medicine study do?

The study by Ohsawa and colleagues sought to answer a simple but powerful question:

If molecular hydrogen (H₂) is such a small and neutral molecule, can it act as an antioxidant within the body?

2.1. Cell experiments

The researchers created acute oxidative stress in cells using three different methods (e.g., using reagents that generate free radicals). Nature

They then exposed these cells to hydrogen dissolved in the culture medium. What they observed:

  • H₂ selectively reduced the hydroxyl radical (•OH), considered one of the most cytotoxic and aggressive

  • Hydrogen did not react significantly with other species that have important physiological functions, such as the superoxide ion (O₂•–)

Result:
👉 The cells were better protected against oxidative damage, without completely blocking the normal signalling mechanisms that also depend on ROS.

2.2. Animal experiments (cerebral ischaemia model)

The next step was a stroke model in rats:

  • Cerebral ischaemia and reperfusion (temporary blockage of blood flow and subsequent restoration) were induced, which generates enormous oxidative stress in the brain.

  • One group of rats inhaled hydrogen gas (H₂) during this process, in low concentrations

  • Another group did not receive hydrogen

The results were impressive: Nature

  • H₂ inhalation significantly reduced the area of brain damage

  • Markers of oxidative stress and cell death decreased

  • Animals that breathed hydrogen showed better neurological protection after ischaemic insult

In summary, the article concludes that hydrogen can act as a therapeutic antioxidant, mainly by neutralising hydroxyl radicals and peroxynitrite, two of the most toxic oxygen radicals. Nature+1

3. What makes hydrogen so special?

In addition to its selectivity, hydrogen has unique characteristics: Wikipedia

  • It is the smallest molecule in the universe – it diffuses rapidly through cell membranes

  • It can cross the blood-brain barrier, reaching the brain

  • It diffuses in both aqueous media and lipid membranes, and can also protect the body’s fats

  • In low concentrations (below 4% in air), it is non-explosive and has a good safety profile

Since 2007, dozens of studies and scientific reviews have reinforced the potential of hydrogen in models of:

4. And where does hydrogen-rich water come in?

The Nature Medicine study mainly used inhaled hydrogen gas or hydrogen dissolved directly in culture medium. But practical questions quickly arose:

“If dissolved hydrogen has these effects, could hydrogen-rich water (e.g., produced by water ionisers) have an impact on health?”

Several subsequent studies have looked at precisely this: water with dissolved hydrogen (sometimes called “hydrogen-rich water” or reduced water) administered orally to humans and animals, with encouraging results in parameters such as: dovepress.com+1

  • Reduction of oxidative stress markers

  • Improvement of some metabolic indicators in specific groups (metabolic syndrome, etc.)

  • Subjective improvement in fatigue and well-being in some pilot trials

⚠️ Important note:
These studies are still in development. Although the results are promising, this is not a “miracle” or a cure. Ionised, hydrogen-rich water should be seen as:

  • A potential aid in reducing oxidative stress

  • A tool for improving hydration patterns

  • Never as a substitute for diagnosis, medical treatment, or a healthy lifestyle

5. What does this mean for you in your daily life?

From a practical standpoint, this body of evidence suggests that:

  1. Hydrogen is a ‘smart’ antioxidant

    • It acts where it matters most (highly toxic radicals)

    • It respects ROS with physiological function

  2. Drinking hydrogen-rich water can be a practical way to introduce H₂ into the body

    • Provided that the water contains relevant amounts of dissolved hydrogen

    • And is produced by quality equipment, with materials that are safe for food use

  3. Quality hydration is a basic pillar

    • Even before talking about hydrogen, many people simply do not drink enough water

    • Replacing sugary drinks with better quality water is, in itself, an important step

6. How Aquapure positions itself in relation to this science

At Aquapure, we closely follow developments in science relating to water, molecular hydrogen and health. Therefore:

  • We select water ionisers capable of producing reduced alkaline water rich in hydrogen, designed for long-term domestic use

  • We prioritise equipment with high-quality filtration and materials certified for contact with drinking water

You can find out more about our approach here:

If you are interested in tasting the water and seeing the equipment in operation, you can request a demonstration:

And you can continue to follow other study summaries and educational content on our blog:

7. External links for scientific reading

If you would like to go to the original source and the most recent reviews, here are some useful links:

8. How to turn knowledge into action

If this topic has piqued your curiosity, here are some practical suggestions:

  1. Get informed

    • Read the articles above, talk to your healthcare professional if you have chronic conditions or are taking medication.

  2. Improve your daily hydration

    • Cut down on soft drinks and sugary beverages.

    • Prioritise good quality water; if it makes sense for you, explore the option of ionised, hydrogen-rich water.

  3. Try it out

Conclusion

The 2007 Nature Medicine article was a turning point: it showed that molecular hydrogen can act as a selective antioxidant, with the ability to protect cells and brain tissue in models of acute oxidative stress. Since then, research has advanced and opened the door to practical applications, including hydrogen-rich water as a possible health support tool.

At Aquapure, our goal is to translate this science into simple choices for your everyday life: better water, better habits, more awareness about what you drink – always with transparency and respect for scientific evidence.