Are the Benefits of Hydrogen Water Backed By Science?

Hydrogen is ubiquitous in nature, making up approximately 75% of all particle mass in the universe. Recent research has been investigating the potential health benefits of molecular hydrogen (H2) gas therapy, which is suggested to treat over 60 human diseases [1]. Lately, though, the focus has shifted towards hydrogen water benefits.

So, are the health benefits of drinking hydrogen-rich water really justified by science or is this merely another alkaline-water-esque fad? As crazy as it seems, preliminary human studies suggest hydrogen water benefits are quite promising.

But let’s be clear: hydrogen water is not the same as alkaline water.

Despite the ambitious claims that companies and misinformed nutrition zealots make about alkaline water, there is virtually no substantial evidence to suggest that it's any better than drinking purified tap water. About the only thing alkaline water may do is reduce the symptoms of reflux disease by making the stomach less acidic and denaturing pepsin [2].

On the contrary, hydrogen water appears to have systemic health benefits by reducing oxidative stress and inflammation.

For example, a recent 12-week study in patients with rheumatoid arthritis showed that drinking roughly half a liter of hydrogen water daily cleared their symptoms and helped them achieve remission [3]. And guess what? These benefits persisted even after they stopped drinking hydrogen water.

Other potential benefits of hydrogen-rich water and molecular hydrogen therapy are myriad, including:

• Increasing antioxidant status and attenuating oxidative stress

• Protecting neurons from degeneration and defending against cognitive decline

• Fighting stress and anxiety (i.e. H2 is nootropic)

• Enhancing athletic performance by “buffering” the blood and reducing recovery time (a similar effect is seen with beta-alanine supplementation)

• Mediating inflammation and promoting tissue healing/repair

• Increasing blood pH, making it a potential treatment for metabolic acidosis

Yet, the general public’s skepticism remains high when they hear about all ways hydrogen water benefits us, and rightly so. After all, alkaline water is still relevant thanks to some crafty and duplicitous marketing tactics. (Not to say that alkaline water is "bunk"; at the very least, it's a source of clean water.)

But hydrogen-rich water seems to actually have evidence-backed health benefits, whereas alkaline water lacks compelling data.

Naturally, you might have several questions: What is hydrogen water? How does hydrogen water work? What are molecular hydrogen supplements?

To answer these questions, let’s take a deeper look at the nature of hydrogen molecules as well as the research behind molecular hydrogen and hydrogen water.

What Is Hydrogen Water?

Hydrogen water is basically the same thing as carbonated water, with the distinction of containing H2 gas instead of CO2. In other words, hydrogen water is water that’s near-saturated with molecular hydrogen molecules. Hence, the terms “hydrogen-rich water” and “hydrogen water” are interchangeable.

Hydrogen is the most abundant chemical element in the universe, making up roughly 3/4th of all particle mass. By virtue of its ability to form covalent bonds with essentially every nonmetallic element and ionic bonds with many metals, hydrogen plays a multitude of roles in the human body and in nature. In particular, hydrogen is an integral component of acid-base reactions since it carries a proton (positive electrical charge) between molecules in solution.

At standard temperature and pressure, hydrogen exists as a volatile, non-toxic gas often referred to as molecular hydrogen or H2. Physically, hydrogen gas is the smallest chemical substance known to man.

The vast majority of hydrogen on Earth is found in organic molecules, most of which are hydrocarbons, and water. While drinking water provides hydrogen bonded to oxygen (H2O), this is not the same as ingesting molecular hydrogen since water and hydrogen gas (H2) have distinct properties and actions in the body.

How Is Hydrogen Water Made?

Hydrogen water is commonly produced by electrolysis (ionization) of water.

Reaction: 2H2O → O2 + 2H2

However, water electrolysis is costly and remains impractical as an everyday resource for hydrogen water.

A simpler, more cost-efficient way to produce hydrogen water is by dunking a small amount of metallic magnesium into purified water, which yields magnesium hydroxide and molecular hydrogen in solution.

Reaction: Mg+2 + 2H2O → Mg+2(OH–)2 + H2

Magnesium hydroxide is not readily soluble in water and precipitates as a white solid. It’s also a strong antacid and the main ingredient in Milk of Magnesia which is known for its laxative effects.

Thankfully, the relative concentration of magnesium hydroxide produced when generating near-saturated hydrogen water is minimal and won’t have much biological effect.

Only about 30 mg of metallic magnesium is needed to create 500 mL of near-saturated hydrogen water.

What about Molecular Hydrogen "Supplements"?

Many supplement companies are now selling hydrogen water supplements that are egregiously overpriced magnesium pills cleverly branded as “molecular hydrogen tablets.” However, consumers are likely to believe these supplements contain actual molecular hydrogen, which they most certainly do not.

Why’s that, you ask?

Well, molecular hydrogen exists as a gas at room temperature and standard pressure conditions. This is why conventional clinical use of molecular hydrogen entails inhaling hydrogen gas. 

For molecular hydrogen to be in liquid or solid phase requires extremely low temperatures below -425 degrees Fahrenheit. This is why liquid hydrogen is often used in cryogenics and can cause severe frostbite upon contact.

Moreover, molecular hydrogen readily reacts with oxygen in the air and combusts, which would make it quite dangerous to carry around molecular hydrogen tablets even if it were possible/practical.

Therefore, the concept of molecular hydrogen tablets is just silly.

The Trouble with Storing Hydrogen Gas in Water Bottles

Water that is near-saturated with hydrogen contains about 1.6 parts per million (ppm) of H2, but the gaseous hydrogen molecules dissipate quickly and can diffuse through glass containers, metal cans, and plastic bottles. As you can imagine, this presents quite the conundrum for long-term storage of hydrogen water.

Very specific bottling techniques, usually using thermoplastics lined with acrylic resin, are necessary to keep the hydrogen gas from escaping and allowing as little air in the bottle as possible. Ideally, hydrogen-rich water should be consumed as quickly as possible (i.e. within an hour) after it’s opened and the bottle it’s in should remain tightly sealed and out of direct sunlight between sips. Interim storage of hydrogen water should be in a cool, dark environment.

Realistically, hydrogen water kept at the supermarket for weeks or months at a time will lose a good amount of the hydrogen gas by the time it reaches the consumer, making the efficacy and potency of such products questionable.

Difference Between Hydrogen Water and Alkaline Water

There is a theory that alkaline water releases molecular hydrogen, therefore making it beneficial. This notion is misguided for several reasons.

Firstly, alkaline water isn’t the same as water saturated with molecular hydrogen. You can have alkaline water with a low amount of H2 gas since alkaline water isn’t intrinsically saturated with hydrogen gas.

The main thing hydrogen water researchers test for is the concentration of H2 in the water, which is distinct from the pH (i.e. the “Potential of Hydrogen”). The pH measures the acid-base potential of a solution according to the concentration of free hydrogen ions ( H+) it contains. A greater concentration of H+ ions makes the solution more acidic and a lower concentration makes it more alkaline/basic.

Nevertheless, adding hydrogen gas to tap water will slightly increase the pH (i.e. make it more alkaline). It’s important to consider that most tap water is alkaline as is, usually between 7.1-8 pH. Tap water that’s saturated with hydrogen generally has a pH between 8.3-9.3.

Regardless, the pH of hydrogen water doesn’t tell you anything about the amount of hydrogen gas in it. Most of the research regarding the benefits of hydrogen water don’t even test the pH of the water. The evidence thus far indicates that the pH of hydrogen water is somewhat irrelevant to the mechanisms by which it works in the body.

Note that many holistic health advocates suggest you can create hydrogen water by mixing baking soda (sodium bicarbonate/NaHCO3) in water, which is nonsense. Adding baking soda to water slightly ionizes the water into carbon dioxide and sodium hydroxide (lye). (See reaction below.)

Reaction: NaHCO3 + H2O → NaOH + CO2

In other words, the gas (bubbles) you see when mixing water and baking soda is carbon dioxide, not hydrogen gas. Adding baking soda to water will increase the pH a tad due to the sodium hydroxide ions, but there is very little evidence that drinking alkaline water leads to many benefits anyway so it’s a moot point.

Hydrogen water, however, has been shown to increase bicarbonate levels in the blood of physically active men, which consequently made their blood pH increase (i.e. more alkaline) [4].

On that note, let’s take a look at a few notable human studies on hydrogen water consumption.

Human Research Behind Hydrogen Water Benefits

Only a few human studies pertaining to hydrogen water benefits exist at this point in time, but the limited data that is available shows promise.

Human Study 1: Hydrogen Water Protects Newborn Brain from Injury Caused by Insufficient Blood Flow

This is one of the first human studies pertaining to hydrogen water. Researchers split newborns with hypoxic-ischemic encephalopathy (HIE) – a congenital disease in which the brain doesn’t get enough oxygenated blood – into two groups. One group was orally administered hydrogen water for 10 days (0.6 ppm, about 50 mL per day), and the other was treated with conventional medications for HIE.

After the study period, the researchers found that the newborns who received hydrogen water had significantly lower serum levels of biomarkers for HIE than the newborns who were treated conventionally. In addition, the newborns that drank hydrogen water scored markedly better on developmental testing, which included things like muscle tone, disturbance of consciousness, and primitive reflex recovery time.

Human Study 2: Hydrogen Water May Enhance Athletic Performance

This two-week study was done in healthy, physically active men. The placebo group was instructed to drink 2 L of tap water daily and the experimental treatment group was given four 0.5 L bottles of hydrogen-rich water to drink each day. At the end of the two weeks, both groups went through a workout and had their blood pH tested.

The results showed that both fasting and post-exercise blood pH increased by a small, but statistically significant, margin (+0.01-.10) in participants who drank 2 L of hydrogen-rich water for two weeks.

Those who drank tap water had no significant changes from baseline in either parameter. The change of pH values in those who drank the hydrogen water appears to be caused by an increase in blood bicarbonate.

Sodium bicarbonate (baking soda) has long been known to blunt exercise-induced lactic acid buildup [5]. Some athletes even take baking soda as a “supplement” before they train to enhance their performance.

Before you go off and buy a huge container of baking soda to stack with your pre-workout supplement, be aware that all the extra sodium intake from such practices may present issues in its own right.

Also, downing a tablespoon of baking soda before you hit the gym isn’t too pleasing for the palate – consider yourself warned.

The promising news is that hydrogen water may indeed be a practical alternative for “buffering” the blood with bicarbonate, which subsequently can help athletes and gym-goers train harder.

But not so fast…

Having too much bicarbonate in the blood is indicative of metabolic alkalosis –  a dangerous condition in which blood pH it’s too high for normal cellular physiology. A normal level of blood bicarbonate is 23-31 mEq/L.

After just 14 days of drinking hydrogen water, several of this study’s participants had blood bicarbonate levels above 32.

This suggests that there may be safety issues to drinking hydrogen water daily and for extended periods of time (especially in those who don’t regularly exercise).

Human Study 3: Hydrogen Water Reduces Symptoms of Rheumatoid Arthritis

This is arguably the most compelling human study to-date. 20 patients with rheumatoid arthritis (RA) drank 530 mL of highly concentrated hydrogen water (4 to 5 ppm) every day for four consecutive weeks. After the first four weeks were complete, patients underwent a 4-week wash-out period (i.e. no hydrogen water consumption),  after which they resumed drinking the hydrogen water for another four weeks.

All 20 patients experienced a reduction in disease activity at the end of the study, but four of the patients did not achieve a statistically significant improvement in their RA symptoms. On average, the disease activity score (DAS28) score dropped from 3.83 to 3.02 in the first drinking period and from 2.83 to 2.26 in the second drinking period, indicating that remission of rheumatoid arthritis was achieved.

Four of the patients did not report any swollen or painful joints and were completely symptom-free. Interestingly, during the wash-out period, the average DAS28 score continued to decrease by a small margin, from 3.02 to 2.83.

How Does Hydrogen Water Work?

Okay, so hydrogen water may be beneficial, but why? What is it about molecular hydrogen that makes it therapeutic?

The nature of molecular hydrogen as a healing agent remains a bit of a mystery, but there are several working theories outlined below.

Antioxidant Benefits of Hydrogen Water

In contrast to normal tap water, hydrogen water has a highly negative redox potential, which is basically the nerdy way of saying that works as an antioxidant and can reduce oxidative stress.

Antioxidants are molecules that accept electrons from free radicals and reactive oxygen species, thereby neutralizing them. For example, research has shown that the hydrogen gas in hydrogen water is able to diffuse across the blood-brain barrier and exert protective effects on neurons [1].

Hence, antioxidants are a crucial aspect of human health since they help control oxidative stress and defend against cytotoxic oxygen radicals (and nitrogen radicals).

Chronic oxidative stress is the putative underlying cause of many modern health conditions, including cardiovascular disease, metabolic syndrome, cancer, Alzheimer’s disease, arthritis, and much more [6].

Vegetables and fruits are everyday examples of foods that are rich in antioxidant vitamins and minerals, such as vitamin E and vitamin C.

But there’s more complexity to molecular hydrogen…

Other Health Benefits of Drinking Hydrogen Water

It's a bit of a paradox that drinking hydrogen water produces very transient and slight increases in plasma hydrogen when compared to hydrogen gas therapy. Hydrogen gas (2%) is estimated to be 104 times more potent than saturated hydrogen water (1.6 ppm).

Moreover, most of the molecular hydrogen consumed from hydrogen water is exhaled within 10 minutes of ingestion. While molecular hydrogen can be readily distributed in the brain, intestines, stomach, liver, heart, and lungs, most of it is expelled through exhalation. As such, tissue levels of hydrogen gas remain very low even after drinking several liters of hydrogen-rich water.

Another discordant observation is that many gut bacteria are able to produce hydrogen gas – an effect potentiated by oral administration of the synthetic sugar lactulose. One would expect that supplementing with lactulose should produce much higher systemic levels of hydrogen gas than those that are achievable by drinking hydrogen water.

However, supplementing with lactulose has failed to reproduce the same effects as hydrogen water [7]. These findings are fairly perplexing and tough to reconcile with the hypothesis that hydrogen water benefits us by thwarting oxidative stress via systemic hydrogen alterations. This phenomenon has left researchers puzzled.

A more plausible supposition at this point is that hydrogen water (but not alkaline water) stimulates the gut to produce more ghrelin, a growth hormone-related peptide that has wide-spanning therapeutic effects throughout the body [9]. In a recent study, researchers found that mice given hydrogen water for four days had nearly double the ghrelin levels as control mice [8]. Alas, it's unclear if this mechanism can be extrapolated to humans.

Hydrogen-Rich Water as a Health Beverage and Sports Drink?

So far, the increase in ghrelin after ingesting hydrogen water has only been confirmed in mice. Going forward, clinical studies are necessary to determine if regularly drinking hydrogen-rich water benefits humans by increasing ghrelin levels as it does in rodents.

Such studies should examine the dose-dependency and durability of this effect and what it ultimately means for our health and longevity. It’s also prudent for future studies to determine whether drinking hydrogen water during a fast has a stronger effect since ghrelin naturally decreases after feeding and increases during fasting.

If that proves to be the case, there’s a good chance hydrogen water will become the drink of choice for those who follow intermittent fasting.

Lastly, there's potential that hydrogen water benefits athletic performance since it increases bicarbonate levels in the blood. However, more studies are needed to confirm the safety of drinking hydrogen water for extended periods of time.

At this juncture, there are plenty of reasons to be excited about the prospect of hydrogen water, but the scanty amount of human research that’s currently available only goes so far.

Hopefully, that will change in the not-too-distant future. Until more conclusive human research on hydrogen water benefits surfaces, stick to good old purified tap water, spring/mineral water, and carbonated/sparkling water.

If you want to try the magnesium method for creating your own hydrogen-rich water, there are a handful of options out there by searching for molecular hydrogen tablets. Just be realistic with your expectations.

No molecular hydrogen supplement is going to be a panacea for all that ails you. We simply don’t know if there any long-term benefits of hydrogen water in humans.

Pragmatically speaking, drinking plenty of purified water – regardless if it’s “alkaline” or saturated with hydrogen gas – sets the foundation for your health and athletic performance.