Most beverages people drink every day are acidic, so the list of genuinely alkaline drinks is shorter than you might expect. Plain tap water often lands near neutral (pH 7), certain mineral waters and bottled alkaline waters sit in the pH 7–9 range, and a handful of other drinks like milk and some herbal teas fall on the alkaline side. The marketing around alkaline beverages has exploded in recent years, but the science behind the health claims is more interesting and more limited than either fans or critics tend to let on.
The pH Landscape of Common Drinks
To appreciate which drinks count as alkaline, it helps to see how rare they are. A study that tested 380 beverages widely available to American consumers found that 93% had a pH below 4.0, with nearly 40% falling below pH 3.0, a range considered extremely erosive to tooth enamel.1PubMed Central. The pH of beverages available to the American consumer Sodas, fruit juices, sports drinks, energy drinks, flavored teas, and wine all sit firmly in acidic territory. A separate analysis of bottled waters found that 10 out of 14 beverages tested were acidic, two municipal tap waters were neutral at pH 7, and only two bottled waters were alkaline.2Journal of Dental Hygiene. Is Your Drinking Water Acidic? A Comparison of the Varied pH of Popular Bottled Waters So if you pick a random drink off a store shelf, the odds strongly favor it being acidic.
Which Drinks Are Actually Alkaline
Truly alkaline beverages fall into a few categories. Bottled alkaline water is the most obvious. These products are either drawn from naturally mineral-rich springs or processed to raise their pH. An analytical study of several commercial alkaline water brands found a mean pH of about 7.75, with individual brands ranging from roughly 7 to 8.7.3PubMed Central. Determination of Fluoride and PH Concentration Among Different Brands of Packaged Alkaline Water – An Analytical Study That same study noted that measured pH values were generally lower than what was printed on the labels, so what you see on the bottle may not be what you get.
Beyond bottled alkaline water, some naturally mineral-rich spring waters qualify. One used in a clinical trial had a pH of 8.3 to 8.5, supplemented with magnesium bicarbonate at about 650 mg/L of bicarbonate and 120 mg/L of magnesium.4PubMed Central. A double-blind, placebo-controlled study of the short term effects of a spring water supplemented with magnesium bicarbonate on acid/base balance, bone metabolism and cardiovascular risk factors in postmenopausal women These mineral-rich waters get their alkalinity from dissolved bicarbonates and mineral salts, not from processing.
Plain cow’s milk typically falls around pH 6.5 to 6.7, which is slightly acidic but close enough to neutral that it behaves quite differently in the body than a cola at pH 2.5. Some plant milks, depending on their mineral content and fortification, can sit right around 7 or just above. Certain herbal teas, particularly those brewed from chamomile or ginger, can land near neutral or mildly alkaline depending on the water used and the steeping time. Green vegetable juices made from things like kale, spinach, and cucumber often fall in the mildly alkaline range, though adding citrus or fruit quickly drops the pH.
Coconut water is sometimes marketed as alkaline, but its pH varies and generally hovers around 5 to 5.5, making it mildly acidic. Its composition is mostly sugars and minerals at low concentrations.5EDP Sciences (Fruits). Coconut water uses, composition and properties: a review Some brands add alkaline minerals to bump the pH up, but unprocessed coconut water should not be assumed alkaline.
How Alkaline Water Gets Made
There are two main approaches. The first is electrolysis, where an electric current is passed through water to separate it into alkaline and acidic streams. A bipolar membrane divides the anode and cathode chambers so the two streams do not mix, and the resulting alkaline water has a higher pH and alkalinity than the original tap water.6SSGM Journal of Science and Engineering. Design and Development of Water Ioinzer Home water ionizers use this approach, and they have become popular in parts of Asia and increasingly in Western markets.
The second approach is mineral addition. Manufacturers dissolve alkaline minerals like calcium, magnesium, or potassium bicarbonate into purified water. This raises the pH and also adds minerals that contribute to the water’s buffering capacity, meaning the water can resist pH changes when it encounters stomach acid, at least to a point. Some products use a combination of both methods. The distinction matters because electrolyzed water without added minerals may have a high pH but relatively little buffering capacity, so it neutralizes quickly in the stomach.
The pH of a Drink Versus Its Effect in the Body
One of the biggest misconceptions in the alkaline-beverage world is that drinking something alkaline will meaningfully change your body’s pH. It won’t, at least not your blood pH. Your body holds arterial pH within a tight range of 7.35 to 7.45 through chemical buffering, respiratory regulation of carbon dioxide, and the kidneys’ ability to excrete or reabsorb hydrogen and bicarbonate ions.7PubMed Central. Acid-base balance: a review of normal physiology These systems are extremely powerful, and a glass of pH 9 water barely registers against them.
What can shift, though, is urine pH and potentially the acid load that your kidneys have to deal with. Nutritional researchers use a concept called potential renal acid load, or PRAL, which estimates how much acid or alkali the body produces based on the nutrient profile of what you consume. Foods and drinks with a negative PRAL increase the production of alkali precursors, while those with a positive PRAL increase acid production.8Pharmacological Research. Dietary acid load: Mechanisms and evidence of its health repercussions So the interesting question is not whether alkaline water changes your blood pH (it does not) but whether it changes the downstream workload on your kidneys and the chemistry of your urine. The evidence suggests it can, to a modest degree.
What the Health Research Actually Shows
Research on alkaline water’s health effects is scattered across several domains, and the results are a mixed bag. Some findings are genuinely interesting. Others are too preliminary to act on.
Acid Reflux
One of the more compelling lab findings is that water at pH 8.8 irreversibly inactivated human pepsin, the enzyme responsible for the tissue damage in reflux disease. Its acid-buffering capacity also far exceeded that of conventional-pH waters.9PubMed. Potential benefits of pH 8.8 alkaline drinking water as an adjunct in the treatment of reflux disease This is an in vitro result, meaning it was observed in a test tube rather than in a living person, so it does not prove that drinking alkaline water will cure reflux. But the mechanism is plausible and has attracted further research interest. If you deal with occasional heartburn, alkaline water might be worth trying as a supplement to standard treatment, though it should not replace medication prescribed by a doctor.
Bone Health
A small body of research suggests that alkaline mineral water could reduce bone loss. One trial found that alkaline water rich in bicarbonate led to a significant decrease in markers of bone resorption even in people who already had sufficient calcium, while acidic calcium-rich water showed no such effect.10PubMed. Alkaline mineral water lowers bone resorption even in calcium sufficiency: alkaline mineral water and bone metabolism A study in postmenopausal women with osteoporosis reported that alkaline water intake was associated with maintaining bone density, particularly in the spine, by reducing urinary calcium excretion.11PubMed Central. Effect of Alkaline Drinking Water on Bone Density of Postmenopausal Women with Osteoporosis These are small studies and not definitive, but the direction of the findings is consistent: the bicarbonate content in alkaline water may help the body hold onto calcium rather than dumping it into urine.
Kidney Stones
The kidney stone angle might be the most practically supported area. Bicarbonate-rich mineral water increased urinary pH and citrate excretion in healthy men, while decreasing oxalic acid excretion and the relative supersaturation for both calcium oxalate and uric acid stones. The researchers noted that the effect was comparable to standard pharmaceutical alkalization therapy using sodium potassium citrate.12British Journal of Nutrition. Cross-over study of the influence of bicarbonate-rich mineral water on urinary composition in comparison with sodium potassium citrate in healthy male subjects A review echoed this, concluding that the bicarbonate content of mineral water can contribute to urine’s ability to inhibit stone formation by raising urinary pH and citrate.13PubMed. Can the manipulation of urinary pH by beverages assist with the prevention of stone recurrence? An animal study further showed that mice given alkaline mineral water were partly protected from progressive kidney damage caused by calcium oxalate crystal accumulation.14PubMed Central. Protective Effect of Alkaline Mineral Water on Calcium Oxalate-Induced Kidney Injury in Mice For people who are prone to kidney stones, drinking mineral water with a high bicarbonate content is a reasonable, low-risk strategy to discuss with a urologist.
Alkaline Water and Athletic Performance
A few studies have tested whether alkaline water helps athletes deal with the acid buildup from intense exercise. In a double-blind trial involving combat sport athletes, drinking mineral-based highly alkaline water improved hydration, acid-base balance, and anaerobic exercise performance compared to regular water.15PubMed Central. Alkaline water improves exercise-induced metabolic acidosis and enhances anaerobic exercise performance in combat sport athletes A related study found that athletes hydrated with alkaline, low-mineralized water showed more efficient lactate use after high-intensity interval exercise and favorable changes in hydration markers.16Biology of Sport. The effect of mineral-based alkaline water on hydration status and the metabolic response to short-term anaerobic exercise
Separate from exercise performance, one study looked at whether high-pH electrolyzed water affected blood viscosity after exercise-induced dehydration. Participants who drank the alkaline water showed about a 6% reduction in high-shear blood viscosity compared to roughly 3% with standard purified water, a statistically significant difference. Other rehydration markers, though, showed no meaningful advantage.17PubMed Central. Effect of electrolyzed high-pH alkaline water on blood viscosity in healthy adults These studies are small and specific to particular athletic contexts, so the practical significance for a recreational jogger or someone at the gym is unclear. But the findings are at least consistent with the idea that alkaline water may offer a marginal edge during very intense exercise.
What Alkaline Water Does Not Do
Claims that alkaline water reshapes your gut microbiome or regulates blood sugar have not held up well under controlled testing. A randomized crossover trial in which participants drank at least two liters daily of either alkaline (pH 9) or neutral (pH 7) water for two weeks at a stretch found no significant effect on gut microbiota diversity, glucose regulation, or low-grade inflammation.18Scientific Reports. The effect of drinking water pH on the human gut microbiota and glucose regulation: results of a randomized controlled cross-over intervention That does not mean alkaline water has zero effect on digestive health in all circumstances; an animal study did find that a specific metasilicate-based alkaline mineral water improved intestinal microflora in piglets with stress-induced diarrhea.19Pharmacological Research. Metasilicate-based alkaline mineral water confers diarrhea resistance in maternally separated piglets via the microbiota-gut interaction But stressed piglets and healthy humans are very different contexts. The evidence for dramatic gut health or metabolic benefits in typical adults simply is not there yet.
A cross-sectional study of postmenopausal women did find associations between habitual alkaline water consumption and lower fasting blood glucose, lower triglyceride-to-HDL ratios, lower diastolic blood pressure, and even better sleep and grip strength.20PLOS ONE. Associations of alkaline water with metabolic risks, sleep quality, muscle strength: A cross-sectional study among postmenopausal women The catch with a cross-sectional study is that it captures a snapshot, not a cause-and-effect relationship. Women who choose alkaline water may also exercise more, eat better, or differ in other ways that explain the results. These associations are worth noting, but they are not proof that alkaline water caused the improvements.
Safety and Who Should Be Careful
For most healthy people, drinking alkaline water in normal amounts is unlikely to cause harm. Your kidneys and lungs are well equipped to handle the extra alkali. But “normal amounts” is doing some heavy lifting in that sentence. A comprehensive review outlined several scenarios where alkaline water poses real risks:21Frontiers in Medicine. The health benefits of alkaline water: is it a fact or marketing myth?
- Kidney disease: People with reduced kidney function cannot efficiently clear excess alkali and minerals. Habitual intake of mineral-rich alkaline water can raise the risk of electrolyte problems, including dangerously high levels of potassium, calcium, or magnesium. A published case report described a child with chronic kidney disease who developed calcium-alkali syndrome after drinking alkaline water while also taking calcium carbonate, requiring the water to be discontinued before kidney markers improved.
- Reduced stomach acid: Persistently neutralizing gastric acid with high-pH water may impair protein digestion and reduce absorption of iron, calcium, magnesium, and vitamin B12. This is a concern for people who already take acid-suppressing medications.
- Heart failure and hypertension: Alkaline waters with high sodium content can worsen fluid retention or raise blood pressure in people with heart failure, especially those on diuretic therapy.
- Metabolic alkalosis: Chronic consumption of very high-pH water can, in susceptible individuals, push blood chemistry toward alkalosis, with symptoms ranging from nausea and tingling to more serious cardiac and neuromuscular complications in severe cases.
These risks are not common in healthy adults drinking moderate amounts, but they are real enough to warrant caution for anyone with kidney disease, heart failure, or conditions that already affect acid-base balance. As with overhydration in general, drinking excessive volumes of any water, alkaline or not, can dilute plasma sodium dangerously.
The Dental Angle
Here is an underappreciated practical use for alkaline water. Given that the vast majority of commercial beverages are acidic enough to erode tooth enamel, researchers have looked at whether rinsing with alkaline ionized water after consuming acidic drinks could offer some protection. A review on this topic described alkaline ionized water as a potentially helpful remedy, given that eliminating acidic beverages from people’s diets entirely is unrealistic.22PubMed Central. The Onset of Dental Erosion Caused by Food and Drinks and the Preventive Effect of Alkaline Ionized Water The logic is straightforward: if acidic beverages lower the pH at the tooth surface and drive mineral loss, rinsing with alkaline water could help restore a safer pH faster. This is a modest, evidence-supported use that has nothing to do with the grander health claims typically associated with alkaline water marketing.
A Very Old Idea in New Packaging
The idea that mineral-rich water has healing properties is genuinely ancient. Drinking and bathing cures using mineral spring water rank among the oldest medical therapies.23PubMed. Mineral water as a cure The therapeutic use of water was recorded in ancient Greece by at least 1000 BC, and Hippocrates himself wrote about the health significance of different water sources.24PubMed Central. Historical issues of hydrotherapy in thermal-mineral springs of the Hellenic world European spa towns built entire economies around their local mineral springs. What has changed is not the basic concept but the commercial packaging: instead of traveling to a spa, you buy a bottle labeled pH 9.5 at the grocery store.
The continuity is worth noting because it puts the current alkaline water trend in perspective. Humans have gravitated toward mineral-rich water for millennia, and the bicarbonate-rich springs that were prized historically are not chemically different in principle from what modern alkaline water brands are trying to replicate. The gap between the ancient practice and the modern product is mainly about concentration, consistency, and the marketing claims layered on top. European mineral waters still carry designations based on their mineral content and are regulated as such. The alkaline water market in places like the United States is far less standardized, which is partly why measured pH values so often fall short of what the label promises.