Understanding the pH Scale
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 distilled water. Anything below 7 is acidic, and anything above 7 is alkaline, or basic. This scale is logarithmic, meaning each whole number increase or decrease represents a tenfold change in acidity or alkalinity. For instance, a liquid with a pH of 6 is ten times more acidic than one with a pH of 7. Alkaline water stands apart from regular drinking water because of its higher pH level, which is typically between 8 and 9.5 for commercially sold products.
What is Alkaline Water?
Alkaline water is more than just a liquid with a high pH. For water to be truly alkaline, it must also contain alkaline minerals such as calcium, magnesium, and potassium. These minerals contribute to the water's alkalinity and are often a key factor in how people perceive its taste and benefits. Additionally, some proponents discuss the importance of a negative oxidation-reduction potential (ORP), suggesting it gives the water antioxidant properties, though more research is needed on these claims.
The Source of Alkaline Water: Natural vs. Artificial
Naturally Alkaline Water
Natural alkaline water is a result of geological processes. As water flows over mineral-rich rocks, such as springs and aquifers containing limestone and calcium, it naturally picks up alkaline minerals. This infusion of minerals is what increases the water's pH level and contributes to its distinct taste. This type of alkaline water is often considered safe and beneficial due to its natural mineral content. Notable natural alkaline spring sources exist around the world, like in the Himalayas or from certain springs in the US.
Artificially Alkaline Water
Artificially alkaline water is created through various human-made processes. These methods manipulate water's properties to achieve a higher pH. Common techniques include:
- Electrolysis (Ionizers): This method uses an electrical current to separate the acidic and alkaline components of water. The acidic water is funneled away, leaving the alkaline water behind. Some scientists are skeptical of the health claims related to this process, and it does not guarantee a high mineral content without further enrichment.
- Mineral Infusion: Producers can add alkaline minerals, like calcium and magnesium compounds, to purified water to raise its pH. This is a common method for many bottled alkaline waters on the market.
- Home Additives: For a cost-effective alternative, people can add a small amount of baking soda (sodium bicarbonate) or special pH drops to regular water. While this does increase the pH, it doesn't replicate the full mineral profile of naturally sourced alkaline water and can add sodium to your diet.
Benefits and Controversies
The marketing surrounding alkaline water often focuses on a range of potential health benefits, but scientific evidence is often limited or inconclusive.
Purported Benefits (Limited Evidence):
- Better Hydration: Some studies suggest alkaline water molecules are absorbed more efficiently, particularly after exercise. However, the primary factor for hydration is still the total volume of water consumed.
- Acid Reflux Relief: A 2017 study suggested that alkaline water with a pH of 8.8 could deactivate pepsin, an enzyme involved in acid reflux, in a lab setting. Larger human studies are still needed.
- Mineral Supplementation: Natural alkaline water inherently contains beneficial minerals like calcium, which could contribute to overall health.
Scientific Scrutiny and Myths:
- Neutralizing Body Acid: Many claims suggest alkaline water can neutralize the body's acidity and regulate blood pH. In reality, the kidneys and lungs tightly regulate blood pH, and diet has minimal impact on these levels.
- Disease Prevention: Claims that alkaline water can prevent cancer or slow aging lack substantial scientific backing and should be viewed with extreme skepticism.
Potential Risks and Who Should Avoid It
While generally safe for most healthy individuals, excessive consumption of alkaline water can lead to certain risks, and some people should avoid it altogether.
- Disruption of Stomach Acidity: The stomach relies on a highly acidic environment to properly digest food and kill pathogens. Drinking large amounts of alkaline water can disrupt this natural balance.
- Metabolic Alkalosis: Overconsumption can potentially lead to alkalosis, a condition where the body's pH becomes too alkaline. Symptoms can include nausea, muscle twitches, and confusion.
- Mineral Imbalance: Consuming too much of specific minerals can interfere with the absorption of others, leading to imbalances. This is a particular concern with some artificial alkaline products.
- Kidney Concerns: Individuals with pre-existing kidney conditions should be cautious and consult a doctor before drinking alkaline water, as the kidneys are responsible for regulating the body's pH. Excessive mineral intake can put added strain on the kidneys.
- Medication Interference: Alkaline water can react with certain medications, potentially reducing their effectiveness or creating dangerous byproducts. Consult a doctor if you are on medication.
Comparison of Natural vs. Artificial Alkaline Water
| Feature | Natural Alkaline Water | Artificial Alkaline Water |
|---|---|---|
| Source | Underground springs, mineral-rich aquifers | Tap water, purified water treated with electricity or additives |
| pH Level | Naturally occurring, typically 8-8.5 | Can be precisely controlled, often pH 9 or higher |
| Mineral Content | Rich in naturally dissolved minerals (Calcium, Magnesium) | Minerals added post-filtration, potentially less balanced |
| Purity | Dependent on the source; often filtered but retains natural properties | Dependent on the initial water source and filtration method (e.g., RO before ionization) |
| Cost | Varies, but often premium priced bottled water | Ranges from expensive countertop ionizers to cheap pH drops |
| Potential Risks | Low risk for most people due to lower pH | Higher risk of metabolic alkalosis if overconsumed, especially at higher pH |
| Sustainability | Variable, depends on bottling practices; may involve plastic bottles | Potential for reducing plastic waste with home filtration systems |
Conclusion
When considering which water is alkaline, it's clear there are several sources, both natural and artificial, with distinct characteristics. For most healthy people, regular filtered tap water is perfectly sufficient for hydration. While some studies show potential benefits for specific conditions like acid reflux, many health claims for alkaline water are not yet supported by strong scientific evidence. Naturally sourced alkaline water, rich in minerals, is generally considered safer than artificially treated, highly concentrated versions. However, individuals with kidney conditions or those taking medication should consult a healthcare professional before making alkaline water a regular part of their diet. Ultimately, the best choice is often a personal one based on taste, cost, and health considerations. For further reading, Harvard Health provides an expert perspective on whether alkaline water is truly better than plain water.
