Mineral water benefits and side effects

Mineral water vs. regular water

All living organisms need water to survive. Water supports essential physical functions, such as regulating body temperature, protecting joints, and eliminating waste.

While most people in the United States have access to clean drinking water, many people choose bottled mineral water for its perceived purity and potential health benefits.

How does mineral water compare with regular water? Based on the current evidence, the differences are not very significant.

Both types contain minerals and undergo some form of processing. However, by definition, mineral water must contain a certain amount of minerals, and the bottling process takes place at the source.

Tap water

The water in household taps comes either from surface or underground sources.

In the United States, tap water must meet the Safe Drinking Water Act standards established by the Environmental Protection Agency (EPA). These regulations limit the number of contaminants present in water supplied to homes.

Public water suppliers move water from its source to treatment plants, where it undergoes chemical disinfection. The clean water ultimately gets delivered to households through a system of underground pipes.

Tap water naturally contains some minerals, including calcium, magnesium, and potassium. Hard tap water has a higher mineral content, which some consider healthier. However, minerals in hard water form deposits that can corrode pipes or restrict the flow.

Also, despite the efforts of public water suppliers, contaminants from rusted or leaking pipes can pollute drinking water.

Mineral water

Mineral water comes from natural underground reservoirs and mineral springs, giving it a higher mineral content than tap water.

According to the Food and Drug Administration (FDA), mineral water must contain at least 250 parts per million of total dissolved solids. The FDA prohibits these manufacturers from adding minerals to their products.

Minerals that may be present in mineral water include:

• calcium
• magnesium
• potassium
• sodium
• bicarbonate
• iron
• zinc

Unlike tap water, mineral water is bottled at the source. Some people prefer mineral water due to its perceived purity and the lack of chemical disinfection treatments.

However, mineral water may undergo some processing. This can include adding or removing carbon dioxide (CO₂) gas or eliminating toxic substances, such as arsenic.

CO₂ helps prevent oxidation and limits bacterial growth in mineral water. Naturally carbonated water gets its CO₂ from the source. Manufacturers can also infuse their water with CO₂ after extraction.

Below are five potential benefits of mineral water.

1. A source of magnesium

Both bottled mineral water and tap water can be sources of magnesium. This nutrient plays essential roles in regulating blood pressure, blood glucose levels, and nerve function.

Some sources have more or less magnesium than others. The amount of magnesium in water can range from 1 milligram per liter (mg/l) to more than 120 mg/l, depending on the source.

The daily recommended allowance for magnesium ranges from 210 to 420 mg, depending on a person’s age and biological sex. Most people in the U.S. consume less than the recommended amount of magnesium.

Symptoms of magnesium deficiency include:

• loss of appetite
• fatigue
• muscle weakness
• nausea and vomiting
• numbness or tingling
• muscle cramps
• low calcium or potassium levels
• mood changes
• an irregular heartbeat
• seizures

2. Lowering heart disease risk

Having low levels of magnesium may contribute to high blood pressure, congestive heart failure, and conditions that cause irregular heartbeats.

Mineral water rich in magnesium may therefore help lower the risk of cardiovascular disease.

Older research in a 2016 review suggests an inverse link between magnesium levels in drinking water and the risk of death due to heart disease.

A 2022 population-based study from Denmark supports this, highlighting an association between low magnesium levels in drinking water and death due to a heart attack.

The study did not find a link between low magnesium and death due to cardiovascular disease or stroke.

3. Regulating blood pressure

Mineral water may contain large amounts of calcium, magnesium, and potassium, all of which help lower blood pressure.

Calcium is necessary for building and maintaining strong bones. It also regulates the rate and rhythm of the heartbeat.

4. Strengthening bones

Mineral water contains calcium, which helps promote bone strength. When bone tissue breaks down, the body deposits new bone in its place.

During adolescence, new bone is deposited faster than old bone breaks down. However, bone mass density tends to peak in a person’s mid- to late-twenties, which can lead to brittle, weak bones as people age.

Regular exercise and diets rich in calcium can strengthen bones and prevent bone loss.

A 2023 review suggests that calcium-rich mineral waters can promote bone health among other benefits, including promoting cardiovascular function and improving overall well-being.

5. Promoting digestive health

Getting enough magnesium in the diet can help prevent constipation and improve digestive health.

Magnesium draws water into the intestines, which improves stool consistency. It also relaxes the intestinal muscles, supporting regular bowel movements.

According to a 2020 review, drinking mineral water rich in magnesium sulfate may offer a natural treatment for functional constipation.

Risks of drinking mineral water

Mineral water is generally safe to drink. Very little research points to any immediate negative health impacts associated with drinking plain mineral water.

Carbonated mineral water contains carbonic acid, which can cause hiccups or bloating. Sparkling or carbonated water, particularly flavored varieties, can also damage tooth enamel. However, sparkling water may still cause less enamel damage than drinks such as energy drinks.

Although mineral water does not undergo the same disinfection process as tap water because it is bottled at the source, the FDA still requires bottled water companies to:

• protect bottled water sources from germs and chemicals
• test water before and after it is bottled
• follow water safety rules

Plastic toxicity

Many plastic containers contain bisphenol A, or BPA. This chemical can interfere with hormonal function.

Microplastics, tiny plastic particles, are another potential concern. Scientists have identified microplastics in foods and drinks, as well as seafood products, beer, and table salt.

However, scientists are continuing to develop tools to help them identify microplastics, which may lead to ways to reduce them in drinking water.

Environmental concerns

One major issue surrounding mineral water involves the container. The large-scale production of plastic bottles causes pollution and has serious consequences for the environment.

In an older 2016 study, researchers looked at the various environmental impacts of regular water treatment, mineral water in plastic bottles, and mineral water in glass bottles.

They found that tap water processing methods were the most favorable option. The scientists also noted that producing glass bottles consumed the largest amount of raw material and required the most energy.

Summary

Mineral water may contain significant quantities of magnesium, calcium, sodium, and other beneficial minerals. The specific amount and composition of minerals may vary from one type of mineral water to another.

Studies suggest that drinking mineral water may have health benefits, including improved cardiovascular and digestive health. However, little research directly suggests that it is better for a person’s health than tap water.

Drinking carbonated mineral water may cause some tooth erosion, and bottled carbonated water may increase a person’s risk of plastic ingestion.