Water is fundamental to human health, driving cellular functions and regulating body temperature. The pursuit of the “best” water stems from a desire for safety, better taste, and maximizing hydration benefits. With numerous options available, understanding the differences in regulation, treatment, and composition is necessary to make an informed choice for daily consumption.
Municipal Water and Basic Filtration
Public tap water represents the baseline for safety, as it is regulated by the U.S. Environmental Protection Agency (EPA) under the Safe Drinking Water Act. This federal oversight mandates treatment processes, including filtration and disinfection, to protect against microbial pathogens like Giardia and Cryptosporidium. Public water systems are required to regularly test for over 90 contaminants, including heavy metals, and make their results public in annual Consumer Confidence Reports (CCRs).
The most common form of household treatment is basic filtration, often using pitchers or faucet attachments containing activated carbon. These filters improve the aesthetics of water by removing compounds that cause unpleasant tastes and odors. Activated carbon works through a process called adsorption, where contaminants like residual chlorine and certain Volatile Organic Compounds (VOCs) adhere to the carbon’s porous surface.
Simple carbon filters are effective at addressing taste concerns and removing specific disinfection byproducts without stripping the water of beneficial naturally occurring minerals. However, they are not designed to remove all contaminants, particularly dissolved solids or certain heavy metals, which often requires more advanced technology.
Commercial and Specialty Water
Bottled Water
Bottled water is regulated by the Food and Drug Administration (FDA) as a packaged food product, and its standards must be at least as protective of public health as the EPA’s tap water standards. The source of bottled water varies significantly, ranging from protected springs to municipal water that has been further purified, which must be indicated on the label. A major concern with bottled products is the packaging material itself, which can introduce microplastic particles into the water.
Consumers who rely on bottled water ingest an estimated 90,000 more microplastic particles annually compared to those who primarily drink tap water. These microscopic plastic fragments can shed from the bottle during production and storage, raising questions about potential long-term health effects related to chronic inflammation and cellular stress. The cost and environmental impact of single-use plastic bottles are also important considerations when assessing this commercial option.
Distilled Water
Distilled water is created by boiling water into steam and then condensing it back into a liquid, a process that removes all impurities, including both harmful contaminants and beneficial minerals. Because it contains virtually no dissolved solids, it has a flat, bland taste that many people find unappealing for daily drinking. While safe to consume, distilled water is often used for specific applications like medical devices (e.g., CPAP machines) and steam irons to prevent mineral buildup.
Drinking distilled water is not inherently unsafe, provided an individual receives adequate minerals from a balanced diet. However, it lacks naturally occurring electrolytes and may increase urine output, requiring a greater focus on mineral intake from other sources.
Alkaline Water
Alkaline water is marketed based on its higher pH level, which is typically above 7.0, compared to the neutral pH of most tap water. Proponents claim that its higher alkalinity can neutralize acid in the body or offer other broad health advantages. Current scientific evidence, however, does not widely support these claims for the general healthy population.
Some limited studies suggest that alkaline water may help relieve symptoms of acid reflux by neutralizing pepsin, an enzyme in the stomach, and may offer slight benefits for bone density in certain populations. For most people, alkaline water is not substantially better than regular water, and the high cost is primarily due to marketing rather than proven health benefits.
Assessing Quality: Purity and Mineral Content
The best water for daily drinking should be defined by two key metrics: high purity and balanced mineral content. Achieving high purity means removing contaminants that can pose health risks, such as lead and emerging compounds like PFAS (Per- and poly-fluoroalkyl substances). These specific contaminants are not always fully addressed by standard municipal treatment or basic carbon filters.
To target these smaller, persistent contaminants, advanced systems like Reverse Osmosis (RO) or specialized ion exchange resins are necessary. RO systems push water through a semi-permeable membrane, effectively removing up to 99% of dissolved solids, including lead and PFAS. This high degree of purification, however, removes all minerals, which is not ideal for long-term consumption.
Naturally occurring minerals like calcium and magnesium are beneficial to health, contributing to bone strength, muscle function, and a lower risk of cardiovascular disease. Water that is extremely pure but demineralized, such as water treated solely by RO or distillation, can be supplemented with a balanced diet or through a remineralization step after filtration. The most advantageous water employs advanced filtration to remove harmful contaminants while retaining or reintroducing these essential minerals.