What is Alkaline Water?

Bottles of water lined up against water outside.

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If you visit a grocery or drug store, you'll find alkaline water bottles populating the shelves. The beverage market offers a number of alkaline water brands, including the popular Essentia, Core, and Bai. But what is alkaline water?

To understand alkaline water, first, you need to understand pH, which is the measurement of a substance's acidity or basicity. As an overview, pH ranges from 1 to 14. A pH of 7 is neutral, 1 to 7 is acidic, and 8 to 14 is considered basic (or alkaline as its also known). For each increment of pH, you get a 10-fold difference in acidity and alkalinity.

According to the United States Geological Survey (USGS), the pH of items are as follows:

  • pH 10: Baking soda
  • pH 6: Milk
  • pH 5: Coffee
  • pH 3: Tomato juice, soda
  • pH 2: Lemon juice, vinegar

In recent years, following an alkaline diet and drinking alkaline water has grown in popularity. But does it really work?

How is Alkaline Water Made?

Water’s pH changes based on its composition of chemicals and gases. Adding mineral, sodium, and calcium content can alter the pH of water. This means that by simply passing over rocks and streams, water can be made more alkaline. However, alkaline waters on the market typically undergo a process called electrolysis. Electrolysis occurs when manufacturers of alkaline water use a product called an ionizer. An ionizer uses electricity to filter out the more acidic molecules.

Those skeptical of a beverage organization slapping an alkaline label on a bottle of regular water simply to elevate the cost, don't need to worry. Bottled water sold as alkaline water is subject to rigorous U.S. Food and Drug Administration (FDA) regulations. The FDA monitors all bottled water products under the food safety program, and the administration determines whether the beverage companies properly analyze source waters. 

Potential Benefits of Alkaline Water

The substantial health benefits of alkaline water are still unclear, according to scientists and researchers. However, a few studies have concluded the following potential advantages of making alkaline water a hydration choice.

May Improve Digestive Health

Alkaline water may improve gastrointestinal symptoms, according to a 2018 study published in Medical Gas Research. In a double-blind, randomized controlled trial lasting four weeks, patients drank either purified tap water (placebo group) or alkaline electrolyzed water. Researchers took blood tests, evaluated physical fitness, and asked patients to respond to a comprehensive questionnaire. Results showed that the alkalized water contributed to intestinal regularization at a greater level than the tap water.

May Provide A Better Night’s Rest

In the same Medical Gas Research study, researchers found that a large percentage of participants who drank alkaline water said they felt they could sleep soundly and awaken feeling much better than before they started consuming alkaline water.

May Rehydrate More Effectively After Exercise

Alkalized water could help rehydrate you after exercise better than regular water, according to
research from the Journal of the International Society of Sports Nutrition. In this study, researchers examined 100 healthy adults, split 50/50 between males and females. Everyone exercised in a warm environment until they were mildly dehydrated. Then, participants drank either alkaline water or standard water at an amount of two percent of body weight. After a two-hour recovery period, researchers evaluated them.

They found that after experiencing exercise-induced dehydration, drinking electrolyzed,
high-pH alkalized water reduced the amount of water loss by an average of 6.3 percent compared with 3.36 percent with standard purified water.

May Elevate Anaerobic Performance

For anaerobic exercise enthusiasts, alkalized water can enhance your performance. In a double-blind, placebo study, researchers studied well-trained combat athletes and the effect of mineral-based alkaline water on anaerobic capacity. In the study, researchers divided participants into two random groups: an experimental group that consumed alkaline water for three weeks and a control group that drank regular water for the same amount of time. They took samples of blood, urine pH, acid-base equilibrium, and electrolyte status.

Results showed that drinking alkalized water improved acid-base balance and anaerobic exercise performance better than regular water.

May Alleviate Acid Reflux

A study from the Annals of Otology, Rhinology & Laryngology found that alkaline water at a pH 8.8 stopped an enzyme connected to acid reflux disease and reduced stomach content’s acidity level in a laboratory study. Researchers noted that conventional drinking water doesn’t have these capabilities, and alkaline water should be studied further as a supplemental treatment for reflux disease.

May Have Anti-Aging Effects

Recent studies show that aging is related to improper water intake. Because of these investigations, researchers decided to examine the effect of drinking alkaline water daily on aging and the antioxidant response in mice. They found that using alkaline water as a diet supplement highly improves aging at the molecular level.

Potential Disadvantages of Alkaline Water

Although the above results are encouraging and may persuade consumers to purchase alkaline
water, you will find deficiencies in the studies and potential health hazards with this trendy beverage choice.

The following are five disadvantages of alkaline water:

Lacks Sufficient Evidence

Drinking regular, plain water has been shown to also provide similar health benefits as alkaline water, such as the following:

  • Better digestive health
  • Mood improvement
  • More energy
  • Body temperature regulation
  • Weight loss

Although popular health and fitness magazine articles list cancer prevention as one of the
benefits of alkaline water, authors of a systematic review published in the British Medical Journal of all peer-reviewed literature on alkaline water disagree. The review revealed a lack of evidence in using alkaline to treat cancer and stated that distributing information to the public about this cancer treatment is not acceptable.

Potential Side Effects of Altered pH

For those with specific health conditions, such as kidney issues, an excess of alkalinity can be harmful to the body, although this is unlikely to occur solely from drinking alkalinized water. According to the National Center for Biotechnology Information, signs of excess alkalinity include:

  • Nausea
  • Vomiting
  • Heart arrhythmia
  • Confusion
  • Muscle spasms
  • Tingling and numbness
  • Tremors

If these symptoms occur, call 911 or contact a healthcare professional immediately as you might be in metabolic alkalosis.

Contributes to Increased Plastic Waste

Consumers must typically purchase alkaline water in plastic bottles. This contributes to the 60% of plastic that ends up in a landfill, and is also among the 300 million tons of plastic waste created every year, according to the UN Environment Programme (UNEP), an international organization focused on sustainable development.

The UNEP says that more than 99% of such plastics get produced from oil, coal, and natural gas chemicals, which are non-renewable resources and not beneficial to the environment. In short, if you only drink bottled water, you could be leaving a heavy carbon footprint.

An Expensive Alternative

If you make alkaline water your main source of hydration, your food (and beverage) budget may skyrocket. In its last comprehensive study on hydration, The Institute of Medicine of the National Academy stated that men should drink 16 cups and women should drink 11 cups total of beverages per day. This amount in bottled water can add up in dollars quickly.

Beverage companies are taking notice of the alkaline water trend and often charge a few dollars per bottle. The Beverage Marketing Corporation, a research organization, says that sales of alkaline water grew from a $47 million business in 2014 to $427 million in 2017, and keeps reaching unprecedented sales. Even one independent seller in the alkaline water market, Alkaline Water Company Inc., expects to reach $1 billion in sales by 2022.

A Word From Verywell

To prove that it is a worthwhile expense, the health benefits of alkaline water require further review and clinical trials need a higher number of participants. Although certain health advantages were studied, the results aren't conclusive. But the peer-reviewed articles do offer optimism that this beverage may provide benefits to your well-being. Overall, if alkaline water makes you want to drink more often and stay hydrated, then that’s the most important benefit of all.

Consider speaking with a medical professional before incorporating large amounts of alkaline water into your diet. Having a blood pH that is too elevated or too low can cause serious negative effects on your health.

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12 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. FDA. Fda regulates the safety of bottled water beverages including flavored water and nutrient-added water beverages. Published online June 23, 2020.

  2. Fenton TR, Huang T. Systematic review of the association between dietary acid load, alkaline water and cancerBMJ Open. 2016;6(6):e010438. doi:10.1136/bmjopen-2015-010438

  3. Tanaka Y, Saihara Y, Izumotani K, Nakamura H. Daily ingestion of alkaline electrolyzed water containing hydrogen influences human health, including gastrointestinal symptomsMed Gas Res. doi: 10.4103/2045-9912.248267

  4. Weidman J, Holsworth RE, Brossman B, Cho DJ, St.Cyr J, Fridman G. Effect of electrolyzed high-pH alkaline water on blood viscosity in healthy adults. Journal of the International Society of Sports Nutrition. 2016;13(1):45. doi:10.1186/s12970-016-0153-8

  5. Chycki, J., Kurylas, A., Maszczyk, A., Golas, A., & Zajac, A. (2018). Alkaline water improves exercise-induced metabolic acidosis and enhances anaerobic exercise performance in combat sport athletes. PloS One13(11), e0205708. https://doi.org/10.1371/journal.pone.0205708

  6. Koufman, J. A., & Johnston, N. (2012). Potential benefits of pH 8.8 alkaline drinking water as an adjunct in the treatment of reflux disease. The Annals of Otology, Rhinology, and Laryngology121(7), 431–434. doi:10.1177/000348941212100702

  7. Logozzi, M., Mizzoni, D., Di Raimo, R., Andreotti, M., Macchia, D., Spada, M., & Fais, S. (n.d.). In vivo antiaging effects of alkaline water supplementationJournal of Enzyme Inhibition and Medicinal Chemistry35(1), 657–664. doi:10.1080/14756366.2020.1733547

  8. Nakamura Y, Watanabe H, Tanaka A, Yasui M, Nishihira J, Murayama N. Effect of increased daily water intake and hydration on health in japanese adultsNutrients. 2020;12(4):E1191. doi:10.3390/nu12041191

  9. Fenton, T. R., & Huang, T. (2016). Systematic review of the association between dietary acid load, alkaline water and cancer. BMJ Open6(6), e010438. doi:10.1136/bmjopen-2015-010438

  10. Sur, M., & Shah, A. D. (2021). Alkalosis. In StatPearls. StatPearls Publishing.

  11. Institute of Medicine. 2005. Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. Washington, DC: The National Academies Press. doi:10.17226/10925.

  12. FDA. Fda regulates the safety of bottled water beverages including flavored water and nutrient-added water beverages. Published September 22, 2018.