Alkaline water is becoming increasingly popular because of its supposed health benefits, which include detoxifying the body [1], improving athletic performance [1,2], and treating cancer [3]. It is produced through water electrolysis, which involves using an electric current to split water into oxygen and hydrogen gas [4]. This is followed by a transfer of hydroxide ions, which results in acidic and alkaline water which can be individually collected [4]. Although proponents of alkaline water swear by its benefits, the reality is that the science is not as conclusive about what it has to offer.
Some research suggests that alkaline water may indeed have benefits. For example, in a study looking at the effects of alkaline water on rats, a team of researchers led by Toshiki Yoneda found that rats that were given a high-fat diet and alkaline water gained less weight and showed less alveolar bone loss than rats who were only given a high-fat diet [5]. Researchers have also looked at the effects of alkaline water in humans. In a study looking at men and women with metabolic syndrome, another team of researchers led by Tyler LeBaron found that participants who took an alkaline water supplement for 24 weeks showed reduced blood cholesterol and glucose levels, as well as improved inflammation markers compared to participants who received a placebo [6]. In another study looking at the effects of alkaline water on exercise, a team of researchers led by Toshio Mikami found that participants who drank alkaline water before exercising reported less tiredness and exhibited greater endurance than those who drank placebo water [2].
Although the benefits of alkaline water may be compelling, other research provides evidence to refute them. For example, in another study looking at the effects of alkaline water on exercise in athletes, a group of researchers led by Cheong Ooi found that participants who drank alkaline water before exercising did not show improvements in exercise performance or self-reported tiredness compared to those who drank placebo water [7]. In a systematic review of the literature surrounding alkaline diets and water, Fenton and Huang found no studies looking at alkaline water and cancer in humans and concluded that the use of alkaline water to treat cancer is not supported [3]. Finally, some research suggests that alkaline water may even be harmful. For instance, in a study looking at the effects of long-term exposure to alkaline water in rats, a team of researchers led by Marina Merne found that rats who were given alkaline water for 52 weeks showed inhibited growth, having lower body weights than control rats despite having the same food and water intake [8]. In another study also looking at rats, Watanabe and Kishikawa found that rats who were given alkaline water showed degradation of heart muscle myosin and a decrease in creatine kinase activity, both of which may lead to heart muscle scarring and death [9]. From the sparse and conflicting research, alkaline water may continue to be a fad until larger human studies are conducted.
References
[1] Kurzweil, R.; Grossman, T. Fantastic Voyage: Live Long Enough to Live Forever; Rodale, 2004.
[2] Mikami, T.; Tano, K.; Lee, H.; Lee, H.; Park, J.; Ohta, F.; LeBaron, T. W.; Ohta, S. Drinking Hydrogen Water Enhances Endurance and Relieves Psychometric Fatigue: A Randomized, Double-Blind, Placebo-Controlled Study1. Can. J. Physiol. Pharmacol. 2019. https://doi.org/10.1139/cjpp-2019-0059.
[3] Fenton, T. R.; Huang, T. Systematic Review of the Association between Dietary Acid Load, Alkaline Water and Cancer. BMJ Open 2016, 6 (6), e010438. https://doi.org/10.1136/bmjopen-2015-010438.
[4] Henry, M.; Chambron, J. Physico-Chemical, Biological and Therapeutic Characteristics of Electrolyzed Reduced Alkaline Water (ERAW). Water 2013, 5 (4), 2094–2115. https://doi.org/10.3390/w5042094.
[5] Yoneda, T.; Tomofuji, T.; Kunitomo, M.; Ekuni, D.; Irie, K.; Azuma, T.; Machida, T.; Miyai, H.; Fujimori, K.; Morita, M. Preventive Effects of Drinking Hydrogen-Rich Water on Gingival Oxidative Stress and Alveolar Bone Resorption in Rats Fed a High-Fat Diet. Nutrients 2017, 9 (1). https://doi.org/10.3390/nu9010064.
[6] LeBaron, T. W.; Singh, R. B.; Fatima, G.; Kartikey, K.; Sharma, J. P.; Ostojic, S. M.; Gvozdjakova, A.; Kura, B.; Noda, M.; Mojto, V.; Niaz, M. A.; Slezak, J. The Effects of 24-Week, High-Concentration Hydrogen-Rich Water on Body Composition, Blood Lipid Profiles and Inflammation Biomarkers in Men and Women with Metabolic Syndrome: A Randomized Controlled Trial. Diabetes Metab. Syndr. Obes. Targets Ther. 2020, 13, 889–896. https://doi.org/10.2147/DMSO.S240122.
[7] Ooi, C. H.; Ng, S. K.; Omar, E. A. Acute Ingestion of Hydrogen-Rich Water Does Not Improve Incremental Treadmill Running Performance in Endurance-Trained Athletes. Appl. Physiol. Nutr. Metab. 2019. https://doi.org/10.1139/apnm-2019-0553.
[8] Merne, M. E.; Syrjänen, K. J.; Syrjänen, S. M. Systemic and Local Effects of Long-Term Exposure to Alkaline Drinking Water in Rats. Int. J. Exp. Pathol. 2001, 82 (4), 213–219. https://doi.org/10.1111/j.1365-2613.2001.iep0082-0213-x.
[9] Watanabe, T.; Kishikawa, Y. Degradation of Myocardiac Myosin and Creatine Kinase in Rats Given Alkaline Ionized Water. J. Vet. Med. Sci. 1998, 60 (2), 245–250. https://doi.org/10.1292/jvms.60.245.
[10] Unsplash. Photo by quokkabottles on Unsplash https://unsplash.com/photos/6wn80vdAHWc (accessed Feb 11, 2021).