Questions from the Clinic:
What is alkaline water? Is there any scientific evidence to suggest that drinking alkaline water will fight cancer? If so, how does it work? Are there any cancers where it is most useful?
Adequate hydration is among the most important practices to promote physical health and optimize athletic performance.(1) In the body, water lubricates the joints, facilitates digestion, regulates body temperature, maintains blood pressure, and cushions the brain, spinal cord, and other sensitive tissues.(2) Because of these diverse functions, the Mayo Clinic – a world-renowned American medical center – recommends that men consume 3.7 liters of water and women consume 2.7 liters of water per day.(3) That said, not all drinking water is the same. Like other liquids, water can be acidic or basic depending on its potential of hydrogen, or “pH”. Acidic solutions have a pH of <7, whereas alkaline solutions have a pH >7; pure water has a pH of precisely 7 (Figure 1).(4) In recent years, alkaline water and diets have become popular topics of discussion among patients with cancer seeking natural ways to improve their health. Some even testify that it can cure cancer. That said, significant controversy surrounds the efficacy and safety of these strategies, whose mechanistic basis is only beginning to be understood.(5)
II. Mechanism of Action
Results from previous research indicate that the tumor surface and microenvironment are acidic.(6) This lower pH may reflect the common energy pathway of cancer using aerobic glycolysis or the utilization of sugar to make ATP in the presence of oxygen. Anaerobic glycolysis is generally the pathway of energy generation when extreme demand depletes oxygen availability and sugar is processed with the byproduct of lactic acid. Lactic acid then lowers the pH leading to processes to restore homeostasis once the demand is reduced or oxygen becomes available. Thus, the native metabolism of cancer cells tends towards an acidic environment.
In one study conducted at the Massachusetts Institute of Technology, scientists found that tumor acidosis promotes the expression of proteins like Mena(INV) that facilitate cancer cell migration (metastases) in mouse models. Under acidic conditions, other proteins like CD44 undergo a process called alternative splicing and make tumor cells better equipped to break through extracellular tissues around them. Because acidity drives deleterious changes in gene and protein expression, researchers sought to examine the effects of alkalizing the tumor microenvironment. After adding sodium bicarbonate – commonly known as baking soda – into the mice’s drinking water, investigators found that tumor acidity fell and gene expression shifted towards a more normal state. These positive results corroborate data from separate studies, whose findings suggest that sodium bicarbonate can reduce cancer metastases in mice. “Sodium bicarbonate would not be a feasible cancer treatment because it is not well-tolerated by humans, but other approaches that lower acidity could be worth exploring,” notes Frank Gertler, the senior author of the study.(7)
To maintain an acidic tumor microenvironment, cancer cells express surface enzymes like carbonic anhydrase IX or CAIX. Expressed widely across a variety of solid tumors, like breast, colorectal, lung, and cervical cancers, CAIX catalyzes the hydration of CO2 into HCO3- and H+.(8) Much like how a thermostat controls temperature, CAIX functions as a pH-stat for the tumor microenvironment and creates conditions hostile to healthy cells and favorable to cancer cells. Beyond creating an acidic milieu in which cancer stem cells thrive, CAIX regulates the expression of genes (Snail, Notch) that underlie the epithelial-mesenchymal transition – a process that enhances the migratory capacity of cells and marks the initiation of cancer metastasis. By inhibiting CAIX with small-molecule inhibitors, scientists have been able to deplete cancer stem cells form tumors in vivo.(9)
It is important to note that these studies were conducted on animals, instead of humans. The body, in maintaining homeostasis, also continually works to keep blood pH in a narrow range of around 7.4. If this pH moves too far beyond this range, the body’s enzymes will not work properly. As such, drinking alkaline water cannot change the pH of the body to any appreciable degree.(10)
III. Clinical Trial Data
While available evidence from basic research suggests that acidity is essential to tumor growth and metastasis, hardly any studies have examined the role of alkaline water in combatting cancer. Analysts attempting to conduct a systematic review of studies assessing the association between alkaline water and cancer only located one observational study suitable for evaluation. In this study, investigators failed to show evidence suggesting an association between diet acid load or alkaline water for cancer risk.(11) No interventional trials appear to have been conducted to date on alkaline water or alkaline foods as a treatment for cancer.
On clinicaltrials.gov, there is a record for one completed phase 2 trial that measured the effects of alkaline water in reducing skin toxicity in women with breast cancer undergoing radiation therapy. Although researchers did find that alkaline water raised the pH of urine, it did not confer a statistically significant benefit in reducing skin toxicity from radiotherapy.(12) Notably, these findings have not yet been corroborated in studies conducted within the last decade but alone provide negative evidence against the use of alkaline water as an adjunctive treatment to radiation therapy and other chemotherapies forming the current standard of care.
Although scant evidence supports the consumption of alkaline water for combatting cancer, it does appear to confer some health benefits to certain individuals. In particular, alkaline water appears to have therapeutic benefits for individuals with acid reflux disease by mitigating heartburn. The high pH of alkaline water (~8.8) denatures and inactivates the stomach enzyme pepsin, whose activity is tied to gastroesophageal reflux disease.(13) In excess, alkaline water can impair digestion, worsen any pre-existing kidney disorders, and cause dry, itchy skin.(14) Consumption of high-pH water instead of regular water after a strenuous workout also improves the efficiency of blood circulation through the body to a significant degree. More efficient movement of blood increases oxygen delivery throughout the body, thereby enhancing the body’s recovery from physical activity.(15) Other claims tied to alkaline water, like immune system support, weight loss, and general cancer resistance, have not yet been substantiated or systematically refuted and require definitive examination in future scientific investigations.(5)
IV. Cost and Availability
Like many vitamins and natural supplements, alkaline water is available for purchase from many retail stores and online vendors. Compared with pH-neutral bottled water, alkaline water comes at a significant price premium, costing $33.13 for 480 fluid ounces (Figure 2).(16) By comparison, a 20-count of 28 fluid ounce Poland Spring water costs $9.99, which itself is approximately 2,000 times more expensive than the price of tap water per gallon from most municipalities.(17,18) Notable alkalized water brands include Essentia, Glaceau’s Smartwater, Flow, Icelandic Glacial, and Life water. Invigorated Water and EHM also manufacture portable filters that add minerals while boosting the pH of available water. Filtration takes approximately ten minutes and removes heavy metals, chlorine, and other impurities.(19)
Alkaline water ionizers are also widely available for purchase if individuals are willing to invest considerably more money. Several companies, like Japan-based Enagic International, manufacture alkaline ionizers for home use that cost around $4,000.(20) When using these devices, the water must be consumed within 1 to 2 weeks, as the alkalinity will dissipate after that time.(21)
Accumulating evidence from basic research indicates that the acidic tumor microenvironment plays a key role in the proliferation and survival of various cancers. This association, particularly in recent years, has fueled greater interest in alkaline water and alkaline diets that purport to mitigate the likelihood of developing various malignancies. Although proponents of alkalizing foods and water claim many varied health benefits, very little scientific evidence support or refutes these purported benefits. Compared with other natural cancer remedies, alkalized water is affordably tolerated if not consumed to excess. As such, it is suitable for regular consumption and perhaps ideal for individuals who have completed a workout or who suffer from gastroesophageal reflux disease. Going forward, well-designed, adequately powered clinical trials are required to evaluate the clinical efficacy of alkalizing water in patients with cancer. Available data, while promising, comes from preclinical studies and animal models and may not be extrapolated to humans. Until more evidence emerges that confirms the claimed benefits of alkaline water, patients with cancer should not attempt to consume it with treatment intent or create it by adding baking soda or hydrogen peroxide to water.
Stay strong and curious and be your own best doctor,
Charles J. Meakin MD, MHA, MS
Disclaimer: This information is not meant as direct medical advice. Readers should always review options with their local medical team. This is the sole opinion of Dr. Meakin based on a literature review at the time of the blog and may change as new evidence evolves.
1 Judge LW, Bellar DM, Popp JK, et al. Hydration to maximize performance and recovery: knowledge, attitudes, and behaviors among collegiate track and field throwers. J Hum Kinet. 2021;79:111-122.
2 LaMotte S. Benefits of water: are you getting enough fluids to stay healthy? CNN Health. https://www.cnn.com/2017/09/27/health/benefits-of-water-and-fluids/index.html/. Published September 28, 2017. Accessed June 15, 2022.
3 Mayo Clinic. Water: how much should you drink every day? Mayo Clinic. https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/water/art-20044256/. Updated October 14, 2020. Accessed June 15, 2022.
4 Johnson J, Olsen N. The pH of water: what to know. Medical News Today. https://www.medicalnewstoday.com/articles/327185/. Updated December 2, 2019. Accessed June 15, 2022..
5 Goldman R, Meeks S. Alkaline water: benefits and risks. Healthline. https://www.healthline.com/health/food-nutrition/alkaline-water-benefits-risks/. Updated May 5, 2022. Accessed June 15, 2022.
6 Boedtkjer E, Pedersen SF. The acidic tumor microenvironment as a driver of cancer. Annu Rev Physiol. 2020;82:103-126.
7 Trafton A. How tumors behave on acid. Massachusetts Institute of Technology News. https://news.mit.edu/2019/how-tumors-behave-acid-0320/. Published March 20, 2019. Accessed June 15, 2022.
8 Tafreshi NK, Lloyd MC, Bui MM, et al. Chapter 13: carbonic anhydrase IX as an imaging and therapeutic target for tumors and metastases. Subcell Biochem. 2014;75:221-254.
9 Lee S-H, Griffiths JR. How and why are cancers acidic? Carbonic anhydrase IX and the homeostatic control of tumour extracellular pH. Cancers (Basel). 2020;12(6):1616.
10 Mahdawi A. Is alkaline water a miracle cure – or BS? The science is in. The Guardian. https://www.theguardian.com/global/2018/oct/29/alkaline-water-cure-bs-science-beyonce-tom-brady/. Published October 29, 2018. Accessed June 15, 2022.
11 Fenton TR, Huang T. Systematic review of the association between dietary acid load, alkaline water and cancer. BMJ Open. 2016;6(6):e010438.
12 Alkaline water in reducing skin toxicity in women with breast cancer undergoing radiation therapy. https://clinicaltrials.gov/ct2/show/NCT01487954/. Updated June 18, 2015. Accessed June 15, 2022.
13 Koufman JA, Johnston N. Potential benefits of pH 8.8 alkaline drinking water as an adjunct in the treatment of reflux disease. Ann Otol Rhinol Laryngol. 2012;121(7):431-434.
14 West M, Renee J. What are the dangers in drinking alkaline water? Livestrong. https://www.livestrong.com/article/370249-what-are-the-dangers-in-drinking-alkaline-water/. Published September 13, 2019. Accessed June 15, 2022.
15 Weidman J, Holsworth RE, Brossman B, et al. Effect of electrolyzed high-pH alkaline water on blood viscosity in healthy adults. J Int Soc Sports Nutr. 2016;13:45.
16 Amazon.com. Essentia bottled water, 20 ounce, 24-pack, ionized alkaline water; 99.9% pure, infused with electrolytes, 9.5 pH or higher with a clean, smooth taste. https://www.amazon.com/Essentia-Water-Electrolyte-99-9-Percent-Overachieving/dp/B005HG9ERW/. Accessed June 15, 2022.
17 Instacart. Poland spring 100% natural spring water, 28 | 20 oz bottles. https://www.instacart.com/landing?product_id=17315452/. Accessed June 15, 2022.
18 Newcomer L. Bottled water costs us 2,000 times more than tap. Is it worth it? The Daily Beast. https://www.thedailybeast.com/bottled-water-costs-us-2000-times-more-than-tap-is-it-worth-it/. Updated April 13, 2017. Accessed June 15, 2022.
19 Hondorp G. The best alkaline waters for better post-workout hydration. Runner’s World. https://www.runnersworld.com/nutrition-weight-loss/g39441783/best-alkaline-water/. Published March 23, 2022. Accessed June 15, 2022.
20 Leveluk SD 501 Kangen Water Machine by Enagic. The Best Drinking Water. https://thebestdrinkingwater.com/product/leveluk-sd-501-kangen-water-machine-enagic/. Accessed June 15, 2022.
21 Tyent USA. Frequently asked questions on alkaline water & water ionizer machines. https://www.tyentusa.com/learn/alkaline-water/faqs/. Accessed June 15, 2022.