Bottled water is expensive, but some bottled water is more expensive than others. Some of the most expensive brands of bottled water are types of alkaline water. These waters command a high price because their marketing promises a miraculous array of health claims and a cleaner taste than other bottled waters and tap water. So let's examine the product and the hype.

What is alkaline water?

pH scale

Most water has a natural pH of 7. (Photo: Vector mine/Shutterstock)

Alkaline water is less acidic and higher in alkaline compounds than most tap water or regular bottled water. The ratio of acid and alkaline in a substance is measured by the pH scale that runs from 0 to 14. If the pH is below 7, the substance is more acidic. If the pH is above 7, the substance is more alkaline. If it's exactly 7, the pH is balanced, or neutral.

A human's natural pH is 7.4, according to Women's Health, which means it's pretty well balanced on its own. Regular water has a pH of 7. So how does water become more alkaline? There are several ways. Mineral water, water that comes from a natural mineral spring containing compounds like magnesium, potassium, and calcium, is naturally more alkaline than water from other sources.

The various bottled waters marketed as alkaline water — brands like Fiji, Essentia and Real Water — become alkaline either naturally by being sourced from mineral springs or by being filtered, ionized and having minerals added.

It's possible to create your own alkaline water. By simply adding 1/8 teaspoon of baking soda to 8 ounces of tap water, you'll make it alkaline (and also pretty high in sodium), according to wikiHow. You can also purchase pH drops that contain concentrated alkaline minerals to add to water or you can buy a home ionizing machine.

Health claims

fiji water Is this miracle water or just really expensive bottled water? (Photo: Sheila Fitzgerald/Shutterstock)

The health claims about alkaline water are many. The water is said to improve hydration and athletic performance, so much so that it's become somewhat of an obsession in the NBA. True alkaline water believers say it can boost your metabolism and help you lose weight by reducing the need to store fat, lower your risk of cancer, detox your body, prevent diabetes, cure psoriasis, and of course, balance the pH in your body.

The general theory of how this works is that although our kidneys usually do a good job at balancing the body's pH, an increase in acid in our bodies — from things we eat and drink like coffee, alcohol, fried foods, and dairy or specific health problems — makes our bodies work overtime to keep the balance. As they are working overtime, the alkaline nutrients are used to balance our bodies' pH instead of being absorbed and doing their other jobs like being antioxidants or keeping us hydrated. That's what the believers say.

So what does the science say?

The science of alkaline water

water, science experiment The first question to ask when looking at the results of a scientific study is who funded the study? (Photo: motorolka/Shutterstock)

The water brands and websites that recommend the use of alkaline water for your health either point to no scientific studies about alkaline water's affect on health or they point to studies funded by the alkaline water industry.

Gizmodo took a deeper look at the current batch of alkaline water studies. They found the most recent touted by Essentia water (and almost exclusively paid for by Essentia or a consulting firm) tested only for hydration. Scientists measured the viscosity of a subject's blood after they had become dehydrated and then drank Essentia's water or purified water. The results found a "slight" positive effect from the Essentia water; however, this is one study that only included 100 people. And, when Gizmodo interviewed one of the scientists who was paid by Essentia, he said, "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." The scientists were told what to find by the company who was paying them, not asked to do an impartial study.

Gizmodo also looked at 57 different studies done by Japanese researchers. Of them, only four were done on humans, each having 12, 15, 20 or 60 subjects. The results of those studies found that alkaline water "might have some positive effects for diabetes patients or for folks with kidney problems." The studies didn't show positive effects for healthy people.

The science that's out there is either funded by the industry or done on such small samples that it's reasonable to say science has not backed up the health claims that marketers and alkaline water supporters are making.

Perhaps those drinking all this alkaline water and finding positive health effects are reaching those conclusions not because of the alkaline in the water but because of the water in the water. Water is good for us.

It's worth mentioning that it's not just alkaline water that's trendy right now. There's an alkaline diet that is said to have many of the same positive effects of drinking alkaline water. The diet is heavy in fruits and vegetables like broccoli, cabbage, berries, kale, green beans, lettuce greens, cucumbers, peppers, apples, beets and more. When people follow the alkaline diet, they find their health improves. But, common sense tells us that when you're swapping out French fries for kale, your health is going to improve.

Dangers of alkaline water

stomach-cramps Too much alkaline water can lead to gastrointestinal issues. (Photo: Piotr Marcinski/Shutterstock)

For most healthy people, drinking alkaline water or following an alkaline diet isn't harmful and can be helpful simply because they're increasing their consumption of water and healthy food. However, Healthline says that alkaline water can have some negative side effects. It can lower the acidity in your stomach, making it more difficult for it to kill bacteria and other "undesirable pathogens from entering your bloodstream." It can also cause other gastrointestinal issues as well as create skin irritations.

Another danger is altering your body's normal pH to the point of metabolic alkalosis, causing nausea, vomiting, hand tremors, muscle twitches, tingling and confusion, as well as decreasing "free calcium in the body, which can affect bone health."

Robin Shreeves ( @rshreeves ) focuses on food from a family perspective from her home base in New Jersey.

What's the deal with alkaline water?
We look at the claims and the science behind alkaline water, which is said to improve sports performance.