Health & Medicine

‘Raw water’ is the latest health craze. Here’s why drinking it may be a bad idea.

Drinking untreated water, or “raw water,” could expose you to dangerous bacteria, viruses and parasites that can make you sick.
Drinking untreated water, or “raw water,” could expose you to dangerous bacteria, viruses and parasites that can make you sick. Getty Images/Vetta

Hold your canteen under a natural spring and you’ll come away with crystal clear water, brimming with beneficial bacteria as well as minerals from the earth.

That’s what proponents of the “raw water” movement are banking on — selling people on the idea of drinking water that contains the things they say nature intended without the chemicals, such as chlorine, often used in urban water treatment processes. In some areas of the country, it has become a high-dollar commodity, water captured in glass bottles and sold straight to you.

But by shunning recommended water safety practices, experts warn, raw water purveyors may also be selling things you don’t want to drink, like dangerous bacteria, viruses and parasites that can make you sick.

“We’re glad people are so interested in water quality and the value they’re placing in safe water,” said Vince Hill, who heads the Waterborne Disease Prevention Branch at the Centers for Disease Control and Prevention. “But I think it’s also important for people to know where their water comes from, what’s in it, how it’s delivered and whether it’s safe to drink.”

Water — where it comes from, how its treated and what it’s bottled in — has long been the subject of heated debates. Could demineralized water be bad for you in some circumstances? What about using plastic bottles? Do some water systems have dangerous levels of lead? Some communities reject adding fluoride to drinking water, even though it strengthens teeth and is safe at low doses.

But all in all, “we have an incredibly safe and reliable water supply” in the United States, said David Jones, professor of history of medicine at Harvard Medical School.

Federal law requires the Environmental Protection Agency to set standards that ensure tap water is safe to drink. The Food and Drug Administration regulates water that is bottled and sold to consumers.

But raw water is up to you.

“In some respects,” Jones said, “the fact that people are worried filtration is removing necessary minerals is really an extreme case of one of these First World problems.”

Experts say raw water may contain minerals, but a healthful diet will provide those same minerals, and the risk of harmful bacteria, viruses and parasites is not worth any benefit from trace minerals.

Michelle Francl, who chairs the chemistry department at Bryn Mawr College in Pennsylvania, said raw water is fine to drink as long as it’s clean, which is the issue.

“Water pulled from a spring or water that comes out of the tap — the water molecules are identical,” she said. “So the only difference is what else is in there, and some of those things might be innocuous like the minerals, some of them might be not so innocuous. Things like Giardia and bacteria have been found in springs.”

The cleanliness of the water depends on things you can’t see — whether animals have relieved themselves in a stream and left it full of parasites. Or whether there has been groundwater contamination from naturally occurring elements such as arsenic, radon or uranium, or from agricultural pesticides, herbicides and other chemicals.

“The lack of clean water kills hundreds of thousands of children a year,” said Francl. “So this notion of raw water is crazy.”

Water treatment removes harmful bacteria such as E.coli, Salmonella and Giardia, a common parasite that causes diarrhea.

Until a couple of centuries ago, waterborne illnesses were common, before people separated sewage from drinking water. Jones said that in the late 19th century, cities made massive investments in water treatment processes, including sand filtration, in response to epidemics of cholera, a bacterial disease that spreads in water.

“These kinds of changes are likely largely responsible for huge improvements in human life expectancy,” Jones said. He added that life expectancy increased by some 30 years from 1900 to 1970.

Doug Evans, who said he subsists on an organic, plant-based diet, said he has been drinking raw water for nearly two decades.

“If you have heavily processed water with chemicals in it that are designed to kill bacteria, then I think it can really materially alter the body,” he said. “The springs that I will drink from have all been tested, and the closer you’re drinking it to the source, the safer it is. So I think that if you’re drinking from a natural spring at the source, it tastes better. And I feel good drinking it.”

Evans said others should make their own decision about what to drink.

“You want to drink tap water, drink tap water. You want to go buy water that’s been filtered and put in a plastic bottle, I think that has environmental consequences, but I’m not going to protest,” he said.