Alkaline water side effects may include impaired digestion, worsening of a kidney disorder and dry, itchy skin. Generally, experts consider it safe, but research on the long-term effects is extremely limited.
Maintaining hydration is important for health. However, because evidence supporting the wellness advantages and safety of alkaline water is lacking, it's better to drink plain water.
Possible side effects of alkaline water may include worsening of a kidney condition, impaired digestion and dry skin.
Body Acidity and Alkalinity
The pH scale, which runs from 0 to 14, is a measure of acidity and alkalinity. A pH of 7.0 denotes neutrality, a pH below 7.0 denotes acidity and a pH above 7.0 denotes alkalinity.
Unless lung or kidney disease is present, pH is regulated regardless of the beverages or foods you consume. When you drink water that is a little alkaline, the acid in the stomach neutralizes it before it enters the bloodstream.
While proponents of alkaline water say it increases fat burning, neutralizes acidic blood, acts as an antioxidant, slows the aging process and cures disease, studies don't support the claims, states NKFH.
The typical American diet is very acidic due to its high content of protein and processed foods. However, the best way to reduce the acidic load on the body doesn't involve drinking alkaline water: Instead, it consists of eating a diet rich in plant-based foods such as whole grains, fruits and vegetables.
Alkaline Water Side Effects
Since the body strives to maintain pH neutrality, extremes in either alkalinity or acidity can result in adverse health effects, according to the Cleveland Clinic. Elevating the pH too much on the alkaline side can cause problems over time by impairing the digestion process.
Elements in alkaline water might be harmful for anyone with kidney disease or anyone on a medication that affects kidney function, says NKFH. Highly alkaline water can also cause the skin to become itchy, dry and irritated, notes UCLA Health.
The American Council on Science and Health reports that stomach acidity is vital for digestion and nutrient extraction. In addition, many enzymes aren't activated until they have contact with the acidity of the stomach and intestines. With these factors in mind, if alkaline water does, indeed, raise body pH, which would reduce stomach acidity, it could be very harmful for health. To date, no studies have investigated whether the water has this effect on the stomach.
A study published in the International Journal of Experimental Pathology in August 2001 raises questions about the long-term safety of drinking alkaline water. Although the investigation isn't recent and was conducted with rats rather than people, it merits notice because it casts doubt on the notion that the water is harmless. The authors concluded that long-term use of the water appeared to result in systemic effects that were evident in noticeably retarded growth.
In a December 1998 study featured in the Journal of Toxicological Sciences, rats given alkaline water developed fibrosis of the heart. While the investigation is quite old and doesn't involve human participants, it's worth mentioning because it suggests some effects of the water are unknown and may be harmful.
Possible Alkaline Water Benefits
Some studies indicate alkaline water may slow bone loss. More research is needed to see whether the water improves bone mineral density and if the effect is maintained over time, says the Mayo Clinic.
What about alkaline water and cancer? Some proponents say an acidic diet causes cancer and that eating more alkaline foods kills cancer cells: No evidence supports these beliefs, notes the American Council on Science and Health.
One of the most-studied claims of alkaline water involves its use for acid reflux. The Center for Science in the Public Interest states that evidence supporting this benefit is skimpy. A July 2012 study featured in The Annals of Otology, Rhinology and Laryngology found the water raised the alkalinity of material in a test tube, which inactivated pepsin, an enzyme linked to tissue damage in reflux. This test-tube effect would be hard to duplicate in the human stomach, asserts CSPI.
Another claim is that alkaline water hydrates better than plain water. A study published in the Journal of the International Society of Sports Nutrition in November 2016 compared the hydration effects of alkaline water with plain water on dehydrated participants. The alkaline water reduced blood thickness more than plain water.
Because CSPI considers evidence in the above two studies extremely weak, it advises consumers not to waste their money on alkaline water.
Is the Alkaline Diet Beneficial?
Proponents of the alkaline diet claim it can help prevent many maladies by increasing body pH. It's based on the premise that eating acidic foods raises body acidity, which leads to health problems.
The alkaline diet also advocates limiting the intake of meat, eggs, cheese and other dairy foods, which are considered acidic. Because these foods are part of a healthy balanced diet, they shouldn't be excluded.
Although it's true that certain foods produce acidic compounds and others produce alkaline compounds during digestion, they don't affect blood pH. In contrast, some foods change the pH of the urine slightly. The International Food Information Council Foundation notes that only people with chronic kidney disease might benefit from the small increases in alkalinity associated with the alkaline diet.
Despite alkaline foods not changing body pH, they are extremely nutritious. They should be eaten because they're important in a healthy diet rather than for their alkaline effect.
- National Kidney Foundation of Hawaii: "The Buzz on Alkaline Water"
- Cleveland Clinic: "Alkaline Water: Don’t Believe the Marketing Hype"
- UCLA Health: "Ask the Doctors – Is Water With a High pH Safe to Drink?"
- American Council on Science and Health: "Fact Checking PHony Water"
- International Journal of Experimental Pathology: "Systemic and Local Effects of Long-Term Exposure to Alkaline Drinking Water in Rats"
- Journal of Toxicological Sciences: "Histopathological Influence of Alkaline Ionized Water on Myocardial Muscle of Mother Rats"
- Mayo Clinic: "Is Alkaline Water Better for You Than Plain Water?"
- Center for Science in the Public Interest: "Alkaline Water — Find or Fraud?"
- Annals of Otology, Rhinology and Laryngology: "Potential Benefits of pH 8.8 Alkaline Drinking Water as an Adjunct in the Treatment of Reflux Disease"
- Journal of the International Society of Sports Nutrition: "Effect of Electrolyzed High-pH Alkaline Water on Blood Viscosity in Healthy Adults"
- International Food Information Council Foundation: "A 'Basic' Examination of the Alkaline Diet"