“DRINK MORE WATER” is a repeated refrain. It comes with a few caveats, notably regarding the source. For health, the best option is usually municipal water, which gets high ratings in the DC area.
Before a meal, or when feeling hungry, water can help you feel fuller and improve digestion. Before a workout and before bed, water can protect against dehydration; first thing in the morning, it can jump-start the digestive system; and when feeling fatigued, which can be a sign of dehydration, it can give a quick boost to the brain.
The tide continues to turn away from bottled water—and not just in individual plastic bottles, which are an environmental scourge. It also might not be the healthiest source. At least 25% of bottled water is simply filtered municipal tap water, according to the National Resources Defense Council (NRDC), with labels like “purified” and “distilled” meaning safe—but not necessarily safer than tap water. True “spring water” must use those words on the label.
Tap water is monitored by the EPA—with strict regulations and standards under the Safe Drinking Water Act—and testing performed often hundreds of times a month. Only the FDA regulates bottled water, which doesn’t require lab testing. Looking at 10 popular bottled water brands, the Environmental Working Group found 38 contaminants.
High or low measurements of pH can indicate problems with any water. While “pure” water has a pH of 7, tap water with a pH lower than 5 is likely to be polluted; and more alkaline than 9, it may have an unpleasant smell or taste. Slightly alkaline water with a pH between 8 and 9 has become popular for its potential to help with acid reflux and high blood pressure, and with dehydration caused by exercise.
Water with a pH lower than 5.5 can dissolve enamel, the protective outer layer of teeth. The pH of bottled waters varies among brands due to different filtering processes. In a study at the University of Alabama School of Dentistry, the four bottled brands with pH and fluoride levels safest for teeth were Fiji, Just Water, Deer Park and Evamor.
Carbonated water can also erode tooth enamel, traced to the carbon dioxide added to make bubbles, which leaves weak carbonic acid in the water that increases acidity. Some experts argue, however, that added flavorings are the real villain in bringing pH too low. In addition, carbon dioxide can trigger the hunger hormone ghrelin, blamed for weight gain. In one study, people who drank sparkling water had six times the ghrelin level of those drinking still water.
Choosing bottled water, people have learned to avoid BPA, bisphenol A, which is thought to increase risk factors contributing to heart disease, such as high blood pressure. In a 2015 study of adults drinking from containers tainted with BPA, blood pressure rose almost immediately. Softer bottles can also contain estrogen-like compounds with an array of harmful effects.
Bottled water samples sent to be tested in the film “Tapped” contained phthalates—used to make plastic more flexible—and styrene, both risking harmful health effects. New bottles overheated during shipping had the highest levels. And plastic bottles that are refilled and used repeatedly break down, creating small cracks that can harbor bacteria causing colds and flu.
A German study sampling 20 brands of bottled water found 78% of water in plastic bottles had high amounts of “endocrine-disrupting” chemicals. But 33% of those in glass did as well—traced to water sources contaminated with medications like birth control pills that contain hormones.
Microplastics (tiny pieces of plastic), found in more than 90% of bottled water samples in a 2018 study at the State University of New York in Fredonia, are worrisome for their accumulated pollutants, such as polychlorinated biphenyls (PCBs). While these can be absorbed by the gut, health consequences for humans are not known and might depend on the quantity ingested and how quickly they pass through the body.
The most commonly occurring microplastic found was polypropylene, used to make bottle caps. In one bottle of Nestle Pure Life, microplastic concentrations were as high as 10,000 plastic particles/ liter of water. Even the brand “Boxed Water,” which comes in a box, contained high levels of plastic fibers.
The main objections to tap water concern odor and taste—from chlorine added to remove contaminants—as well as occasional local upsurges in lead levels. Microplastics in tap water are traced to airborne microfibers, notably from factories manufacturing synthetic fabrics for clothes. And despite frequent testing, a recent study found Chromium-6 in water from all 50 states—though the risk of cancer, explained in the film “Erin Brockovich,” from the levels measured may be very low. The worst location for unsafe tap water is Florida, where “boil-only” warnings have become a regular occurrence.
For those concerned about contaminants as well as disagreeable tastes and odors, water filters come in “pour through” pitchers, tap attachments, and whole-house systems, with different brands filtering different contaminants. The most popular pitcher-filter brands are Brita for best taste and PUR for more complete removal of contaminants. Consult evaluation review sites—which don’t always agree—before making a choice.
Water for other uses than drinking often needs special treatment as well. In a neti pot (a container designed to rinse debris or mucus from your nasal cavity), for example, water should be either distilled or cooled after boiling for one minute. The next best option is a filter that includes cyst reduction or removal, or that reads NSF53 or NSF58. More than one person has died from brain-eating amoeba after using a neti pot, one after using a Brita Purifier.
For a personal filter purchase, I will rely on my sister, who works with water and environmental issues, and uses a PUR pitcher filter. Until then, what has worked well for our family for decades is Deer Park water, in three- to five-gallon plastic bottles, chilled by a dispenser. While clearly marked “spring water,” with an acceptable acidity of 6.3 and on lists of water unlikely to destroy tooth enamel, Deer Park may be filtered less well than highly rated DC water and may contain microplastics. For convenience, but maybe more for nostalgic reasons or sheer inertia, I am not yet ready to move on.
Every Tuesday in this space, well-being editor Mary Carpenter reports on health news you can use.