Nutrition is a battlefield where everyone seems to have an opinion. Some of those opinions are science-based, and others are veiled quackery with little evidence to back them up. It can be frustrating if you’re simply trying to stay healthy. Do you spend three dollars on the expensive water bottle or just drink it from the tap? Is the science behind a product’s claims valid?
Such is the case with “alkaline water,” or as I will call it for the rest of the story, basic water. It’s nearing summer again, so you might see these basic waters using marketing and a little bit of science to back a claim that somehow they’ll hydrate you better. Lots of studies seem to tout the water’s benefits, but rarely involve actually making people drink it. That means the evidence and cost don’t justify basic water as much more than rich people juice if you have a clean working tap.
“Water is wonderful,” Jo Zimmerman, an instructor in Kinesiology at the University of Maryland School of Public Health told Gizmodo. “But this is hype, not facts, at this point.”
Here’s a quick review of the chemistry if you don’t remember. Water (H2O) is made from two hydrogen atoms and an oxygen atom. Some of those water molecules break, leaving free H+ (hydrogen ions) and free OH- (hydroxide ions). If there’s the same amount of free hydrogen as hydroxide, the solution is neither acidic nor basic, and the measure of the hydrogen concentration, called pH, equals seven. If there are more free hydrogen ions, then the solution is acidic, and the pH is less than seven. If there are more free hydroxide ions, then the solution is alkaline, or basic, and the pH is greater than seven. For every whole number increase in pH, there’s ten times fewer free hydrogen ions.
This is confusing without the math but it’s because the pH scale is a logarithm of a negative exponent.
You can make water more basic a few ways. Either you can strip away some of those extra hydrogens with some kind of water ionizer, or you can put something into the water that adds more hydroxide (like lye) or steals some of the hydrogen ions (like baking soda).
What do people think is so good about basic water? A lot, actually. A Japanese review found lots and lots of papers touting health benefits, and they’ve been drinking it for a long time. The American companies I found brag mainly about superior hydration. Several bottles explicitly say they’re too pure to test with pH strips, though one company, Essentia supplied a document on how to test the pH by other means. Lots of places say that acidic water is bad for you, but the only reputable proof I could find of that was a University of Massachusetts tip sheet that said acidic water itself isn’t bad—it’s only a worry if it leaches heavy metals from the plumbing system, which is horrible if you remember the Flint water crisis. That’s a public health problem, not a hydration problem.
These basic water companies have done a good job convincing people about the benefits of their water, though, since the unreasonably expensive bottle was the only one sold at the checkout line at Whole Foods last week (I was there for a story. I do not shop there).
Alkalinity is already a popular word in the dieting community, and people claim that certain diets can make your entire body’s pH more alkaline, for example. That is unnecessary. Your body really doesn’t want to change properties like pH as it tries to maintain homeostasis. If those properties do change, it’s because you’re actually sick and need to go speak to a medical professional. And if a basic diet makes you lose weight, it’s probably for the same reason any other diet works. It forces you to monitor your food intake, to eat more whole grains and vegetables and to eat less processed food or junk food.
Simply using the word alkaline might set off someone’s “I should drink this because it’s healthy”-o-meter, though.
What does the science say? I only found two studies testing basic water’s hydrating abilities specifically. Essentia has the most recent one, a study in the open-access Journal of the International Society of Sports Nutrition where they test how well reduced ionized water, basic water made by removing free hydrogen, works at hydrating. They told me that this is different from basic water made by adding stuff, though they add some stuff (including baking soda) for taste. The study itself says that there’s no agreed-upon marker for hydration, but uses blood thickness, where thinner blood means more hydrated. It’s a randomized double-blind trial (so it’s rigorous) including 100 people that tested the blood viscosity of folks drinking Essentia’s water versus folks drinking purified water. They had everyone exercise to the point of dehydration and drink either purified water or Essentia’s water.
The alkaline water did seem to cause lower blood thickness numbers in the two hours after drinking it, on average. But most of the hydration markers they used had heavily overlapping error bars for regular water versus alkaline water data points—you can’t completely say that one was better than the other. Think of it this way: If I say “I think Molly was born in January or February and Melvin was born in February or March of the same year,” then you can’t confidently tell me that Molly is older. One variable, systolic blood viscosity, had a statistically significant difference, according to the study. That means there was less than a five percent chance the difference between the alkaline water and regular water would have happened by chance.
Yes, the study was randomized and controlled, and there’s less than a five percent chance that one of the observed effects was random. But it’s a single study that technically has several different hypotheses rolled into one paper, reporting a slight effect. Read this story to learn about the problem with testing lots of things at the same time. There are other things to be skeptical about—Essentia paid for the study and all but one of the authors and one of the editors received money from either Essentia or a consulting firm. The other study from had similar conclusions but was funded by the Glacier Water Company.
Study authors Dr. Ralph Holsworth, board-certified family medicine physician and director of clinical and scientific research for Essentia Water, and Dr. John St. Cyr (the paid editor) stand by the study results. “I think Essentia is dedicated to showing the scientific validity of the product—that’s what they tasked me with and that’s what we achieved,” Holsworth told Gizmodo. I told St. Cyr about my reservations regarding bias, and he didn’t disagree. “Even with pharmaceuticals, when they come up with these studies, people wonder whether they’re doing this because they plan to sell the drug. There are always questions that are raised. I agree with you.” But St. Cyr felt confident in the study, blood viscosity as a hydration marker and Essentia as a product that can hydrate faster.
As for the other benefits, I went through the 57 studies in that Japanese review, one-by-one (I have my notes if you need to see them). Of the 57, a third were tests in rats, mice or worms. Many were just tests on cells in culture. Others were just notes from conference proceedings. Four of the trials had no control—they were observations of people drinking mineral water at a resort. That left four controlled clinical trials, people actually drinking the water—one had 12 patients, one had 15 patients, one had 20 patients and one had 60 patients. The results of those studies were that basic water might have some positive effects for diabetes patients or for folks with kidney problems. That means the review has lots of hints of some benefits, but nothing conclusive. Plenty of things work in cell culture or other animals that don’t work in the human body. I’m sure there must be a study I missed (feel free to send), but would a few more scientists please look at this water in a few more controlled studies in people?
As a note, some of these waters (Essentia included) do happen to taste pretty good. I’m unsure if that’s because I spent three dollars on it. And I’m really trying to see both sides here, but the hypothesis, that this water will cure an ailment or increase your lifespan, has not been tested rigorously. Japanese people live a long time though, so who knows.
Holsworth didn’t know a mechanism for how basic water might hydrate better should the results of the study hold true over time. Nor did he know if this is an effect specific to the kind of basic water with the ions removed rather than just any basic water. I reached out to the other study’s author for comment.
As a reminder, if you’re really excited about any of those purported benefits, you can make water more basic by adding baking soda to it. And mineral water is usually already basic. And in New York City, at least, tap water ranges from about a 7.1 to a 9 on the pH scale, on average about a 7.4, Jessica Wilson, assistant professor of Civil and Environmental Engineering at Manhattan College told Gizmodo. It’s alkaline because of the minerals in it, not because of some ionization process. But no one has been able to tell me why one thing would be better than the other.
That leaves us with some very expensive bottles of water not backed by enough science to justify its cost. If you have a lot of money and want to spend it on something that is already generally available for free, then honestly do whatever. But as Zimmerman told me, “If the choice is between alkaline water and soda pop, then alkaline water is a better bet. Water fountain versus alkaline water, just drink the fountain water.”