The pH Scale Explained
The pH scale is a measure of how acidic or alkaline a substance is, ranging from 0 to 14. A pH of 7 is considered neutral, like pure water. Any value below 7 indicates increasing acidity, while values above 7 indicate increasing alkalinity. Each whole number on the scale represents a tenfold change in acidity or alkalinity. For instance, a substance with a pH of 8 is ten times more alkaline than one with a pH of 7. In the context of water, alkalinity is often related to the presence of dissolved alkaline minerals like calcium, magnesium, and potassium. Naturally alkaline water, typically from springs, has a higher mineral content that raises its pH. In contrast, artificially alkaline water is created through electrolysis or by adding alkaline minerals.
Recommended pH for Drinking Water
Official Guidelines from the EPA and WHO
Both the U.S. Environmental Protection Agency (EPA) and the World Health Organization (WHO) recommend that drinking water maintain a pH level within the range of 6.5 to 8.5. This range strikes a balance that is both safe for human consumption and effective for municipal water treatment processes. Water within this spectrum is less likely to cause aesthetic issues like an unpleasant taste or odor, and it is less corrosive to plumbing infrastructure. Adhering to this established standard is the safest approach for regular, long-term hydration.
The Case for Slightly Higher pH Water
Despite the recommendations, a popular trend involves drinking alkaline water with a pH between 8.0 and 9.5. Proponents claim it offers health benefits like improved hydration or reduced acid reflux, and some preliminary studies have shown potential effects, such as a test-tube study suggesting pH 8.8 water might inactivate pepsin, an enzyme involved in reflux. However, the overall scientific evidence for these broad health claims is limited and often anecdotal. For example, a 2017 study found that a plant-based diet combined with alkaline water was as effective as medication for reflux, but the diet likely played a significant role. For most healthy individuals, drinking water within this moderately alkaline range is not harmful in moderation.
Risks and Concerns with Very High pH Water
While water up to a pH of around 9.5 is generally considered safe for occasional consumption by healthy individuals, exceeding this level or consuming large quantities consistently introduces notable risks.
Side Effects of Excessive Alkalinity
The human body has robust homeostatic mechanisms involving the kidneys and lungs to maintain a tightly regulated blood pH of 7.35–7.45. Overconsumption of highly alkaline substances can interfere with these natural processes, potentially leading to metabolic alkalosis. Symptoms of metabolic alkalosis can include nausea, vomiting, hand tremors, and confusion. Additionally, the very high pH can interfere with the stomach's natural acidity, which is crucial for killing bacteria and properly breaking down proteins.
Documented Dangers
More concerning are cases involving specific manufactured alkaline waters. In 2020, an outbreak of acute liver failure was reported in individuals who consumed a specific brand of highly alkaline water called "Re2al Alkalinized Water". This led to a voluntary recall of the product. This incident highlights the risks associated with certain manufacturing processes or added contaminants in artificially enhanced water, distinguishing it from naturally sourced alkaline water.
Comparison: Alkaline Water vs. Regular Water
| Feature | Regular Tap Water | Typical Bottled Alkaline Water |
|---|---|---|
| pH Range | 6.5–8.5 (EPA Recommended) | 8.0–9.5 (Commonly Marketed) |
| Mineral Content | Varies by location and source | Higher concentration of alkaline minerals (calcium, magnesium, potassium) |
| Cost | Much more affordable | Significantly higher cost |
| Regulation | Strictly regulated by local municipalities and federal agencies (EPA) | Often less regulated than municipal water; quality depends on the manufacturer |
| Taste | Generally neutral, can vary based on mineral content | Smoother or softer taste due to higher mineral content; can taste bitter at very high pH |
| Primary Purpose | Hydration | Hydration, plus unsubstantiated health claims |
How Your Body Manages pH
It's a common misconception that drinking alkaline water can significantly alter your body's overall pH balance. Your body is equipped with sophisticated systems, including the respiratory system and the kidneys, that work constantly to maintain the blood's pH within a narrow, life-sustaining range. The stomach, with its highly acidic environment (pH 1.5–3.5), neutralizes most of what you consume long before it can impact your blood's pH. The kidneys then excrete excess acid or alkali through urine. For most healthy people, the impact of alkaline water on systemic pH is minimal and temporary.
Conclusion: Finding the Right Balance
When considering what is the highest pH water you should drink, the safest and most reliable answer is water that falls within the EPA-recommended range of 6.5 to 8.5. This ensures safe, consistent hydration without risking the potential side effects of overconsumption. While moderately higher pH water (up to ~9.5) is generally safe for short-term, moderate use, the purported health benefits lack strong scientific evidence. The potential risks of very high pH water, coupled with the documented dangers of certain manufactured products, make extreme alkalinity a risky choice. For most people, focusing on clean, well-regulated water within the normal range is the healthiest and most effective strategy for hydration.
For more information on water safety and contaminants, please consult reliable sources like the Environmental Protection Agency (EPA) website.
This article is for informational purposes only and is not medical advice. Consult a healthcare professional before making significant changes to your diet or water consumption.
