Understanding the pH Scale and Your Body's Balance
The pH scale, which ranges from 0 to 14, measures how acidic or alkaline (basic) a substance is. A pH of 7 is neutral, anything below 7 is acidic, and anything above 7 is alkaline. Our bodies maintain a very tightly controlled pH balance, particularly in the blood, which stays at a slightly alkaline pH of approximately 7.4.
When we drink water, it passes through the stomach, an extremely acidic environment with a pH of 1.5 to 3.5. This stomach acid is a vital part of the digestive and immune systems, designed to break down food and kill harmful bacteria. Therefore, any slightly alkaline water we consume is quickly neutralized by stomach acid, making it ineffective at altering the body's overall pH. The kidneys and lungs also play a significant role in regulating the body's pH, making it highly resistant to change from external sources like drinking water.
The Safe Range vs. Highly Alkaline Water
Both the World Health Organization (WHO) and the U.S. Environmental Protection Agency (EPA) have guidelines for the ideal pH range of drinking water.
Guidelines and Recommendations:
- Safe Range: Most health organizations recommend that drinking water stay within a pH range of 6.5 to 8.5. Water within this range is considered safe, palatable, and does not pose a risk to health or infrastructure.
- Higher pH Levels (8-9.5): Some commercially available alkaline water brands are intentionally produced with a pH of 8 to 9.5. While generally considered safe for moderate consumption, there is limited evidence to support the broad health claims often associated with these products, such as slowing the aging process or preventing chronic disease.
- Extremely High pH (Above 10): Consuming water with a pH significantly higher than 9.5 is ill-advised and could potentially be harmful. The WHO has noted that extremely high pH water (above 11 in animal studies) can cause skin and eye irritation, and a pH above 10 may cause gastrointestinal irritation in sensitive individuals. Water with a pH above 9 has also been linked to potential issues for those with kidney disease, as it can interfere with blood mineral levels.
Risks of Consuming Water with Extremely High pH
While the human body is remarkably resilient, drinking very highly alkaline water on a regular basis carries potential health risks:
- Metabolic Alkalosis: Overconsumption of alkaline substances can potentially lead to metabolic alkalosis, a condition that disrupts the body's pH balance and can result in nausea, vomiting, tremors, and confusion.
- Digestive Disruption: A very high pH can neutralize the stomach's natural acidity, disrupting digestion and potentially impairing the absorption of essential nutrients. It can also interfere with pepsin, an enzyme needed to break down proteins.
- Mineral and Electrolyte Imbalance: The extra alkaline minerals in some of these products can strain the kidneys as they work to regulate the body's pH. This can be particularly risky for individuals with pre-existing kidney conditions.
- Contaminant Exposure: In 2020, an alkaline bottled water product was linked to an outbreak of acute nonviral hepatitis, leading to a recall. The cause was traced to a toxicant introduced during the manufacturing process, highlighting the potential for contamination in unregulated products.
Natural vs. Artificial Alkaline Water
It is important to differentiate between naturally and artificially produced alkaline water, as their mineral content and effects on the body can differ.
How Alkaline Water is Created
- Natural Alkaline Water: This occurs when water naturally passes over rocks, such as springs, absorbing minerals like calcium, magnesium, and potassium that increase its pH. This process is natural and the water's mineral content can offer some benefits.
- Artificial Alkaline Water (Ionized): Produced using an ionizing process, which runs an electric current through the water to separate acidic and alkaline compounds. This method can produce water with a very high pH, sometimes exceeding natural levels. It does not necessarily add beneficial minerals and can concentrate harmful contaminants if not properly filtered beforehand.
Comparison Table: Common Drinking Water pH Levels
| Type of Water | Typical pH Range | Safety Considerations | Key Characteristics |
|---|---|---|---|
| Tap Water | 6.5–8.5 | Safe for consumption, regulated by EPA/WHO | Varies by source, can be slightly acidic or alkaline |
| Neutral Water (Pure/Distilled) | 7.0 | Safe for consumption, lacks minerals | No dissolved minerals or buffers; becomes slightly acidic when exposed to air |
| Commercial Alkaline Water | 8.0–9.5 | Safe in moderation; benefits unproven; risk of contaminants | Often artificially ionized; some contain added minerals |
| Extremely High pH Water | >9.5 | Potential health risks, particularly with prolonged use | Not recommended for consumption; can cause irritation and metabolic issues |
| Acidic Beverages (e.g., Soda, Juice) | 2.5–4.5 | Safe for consumption but highly acidic to the body | High sugar and acidity content; does not impact overall blood pH |
Conclusion
While marketing for alkaline water can be enticing, the highest pH water you can safely drink is typically around 9.5, and even that should be done in moderation. The optimal and safest pH range for daily drinking water remains between 6.5 and 8.5, as recommended by major health organizations. Your body is fully equipped to manage its own pH balance, and introducing excessively alkaline water offers little to no proven health benefits while potentially introducing risks. For most individuals, regular, properly filtered water provides the safest and most effective hydration. For those seeking true nutritional balance, focusing on a healthy diet rich in whole foods and consulting a healthcare professional is a more effective approach than relying on expensive alkaline water.
Mayo Clinic offers an expert-answered FAQ that further addresses the topic of alkaline water.
