The Truth Behind Alkaline Water

Alkaline water will improve your metabolism, boost your liver health, and even help you fight off cancer—at least according to its fans. The actual truth, however, is far more mundane. There is little good evidence for these and many other health claims attached to alkaline water, and the only thing that it’s clearly better at than regular H2O is being more expensive.

Alkaline water is water that’s been treated (often via an ionizer) to have a pH above 7, the normal and neutral pH of water (by pH, scientists are referring to the measure of how acidic or basic a substance is on a scale from 0 to 14). The basic premise behind alkaline water is that it can balance out a body that has become overly acidic, especially by targeting the acidity in our bloodstream, thereby repairing a long list of health conditions supposedly tied to acidity.

One major issue with these claims is that very little research has been conducted to provide even marginal support for them. A few studies have suggested possible benefits of alkaline water, but these have typically involved animals, petri dishes, or very small sample sizes of human volunteers. And larger-scale examinations haven’t turned up much, such as a 2016 review that failed to find any positive link between drinking alkaline water or eating alkaline-rich foods and cancer prevention or improved cancer outcomes.

“Promotion of alkaline diet and alkaline water to the public for cancer prevention or treatment is not justified,” the authors of that review bluntly concluded.

Evidence aside, the very logic of alkaline water is spotty in so many ways. For starters, the human body is already good at ensuring that our organs and fluids stay at the pH they need to be. It’s one of the many examples of homeostasis, or the complex biological processes that ensure stability in a living organism. Our blood’s typical pH even hovers a touch above 7, so it’s already slightly alkaline, and either lowering or raising it for long periods of time would actively be harmful to us.

While there are medical conditions that can disrupt this balance, it’s unlikely that the occasional drop of alkaline water would do much to help us in such a situation, given our biology. The water we drink first enters the very acidic stomach, so it’s quickly neutralized. It might be possible that drinking large quantities of alkaline water could noticeably increase the stomach’s pH, but this would only be temporary, because again, the body is very good at making sure things can stay the same. Also, we thankfully have treatments that can reliably address an overly acidic body when it does happen (such as antacids for the stomach), so there’s no need to roll the dice on something that would be almost certainly useless.

So yes, you should drink plenty of water (though not necessarily eight cups of it a day!) if you want to be as healthy as possible. But you’ll be perfectly fine if you stick to tap instead of the pricier, alkalinized stuff.