Twenty years ago the idea of eating raw food was brave and adventurous, but nowadays preteens are noshing on tuna sashimi at the mall and the ‘raw food movement’ has an ever-growing membership.

Just when we were getting really used to the idea of tossing our pots and pans, however, a new raw trend had emerged: drinking raw water.  In the wake of the Flint, Michigan crisis and with watchdog groups like the Environmental Working Group raising questions about harmful contaminants in tap water across the country, raw water companies like Live Spring Water and Tourmaline Spring claim to offer a bottled-at-the-source alternative that’s so pure it doesn’t need to be treated or filtered—basically the next best thing to dipping your cup into a bubbling mountain stream.

Any water that’s untouched, directly from its natural source—be it a spring or the rain—is technically raw water. Drinking water this way was normal practice throughout most of human history, but companies marketing it to the public in the age of widespread water treatment? That’s something different.

These new raw waters—sometimes also called ‘live’ or ‘living’—are said to taste better and contain beneficial compounds like minerals or probiotics that are often removed from treated water. They are also marketed as free of sewage remnants, antibiotic and medication residue, and other undesirable substances that can leach into the tap water.

These waters also don’t contain chlorine and fluoride, which are added to public drinking water to kill bacteria and prevent cavities, respectively. (Despite the CDC’s assurances that the amounts of chlorine and fluoride in drinking water are safe for human consumption—and data confirming the widespread benefits of fluoride—there are still skeptics out there, which makes raw water appealing to these groups). Raw water companies even promote the fact that their H20 doesn’t pass through lead pipes, which, despite being banned in 1986, have again become a major concern in recent years.

But is it all too good to be true? In a word: yes.

Sure, raw water, with all the claims of its beneficial nutrients and probiotics, sounds great in theory, but it can actually be pretty dangerous, says Christine Moe, Ph.D., the Eugene J. Gangarosa Professor of Safe Water and Sanitation at the Rollins School of Public Health at Emory University. Water treatment (which includes multiple steps to filter out any potentially-harmful components and disinfect the water that reaches our sinks), though not perfect, has a long history of preventing diseases like cholera and typhoid, and protecting people from pathogens like E.coli. These diseases are still significantly more common in parts of the world that lack this infrastructure, explains Moe.

“Raw water is a huge question mark in terms of its contaminants and supposed benefits,” Moe says. It’s very possible that straight-from-the-source water contains substances like soil, microorganisms, and even remnants of animal feces (yes, poop) that can be dangerous—especially for people with compromised immune systems, she adds.

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The bottom line: It’s much more important for your drinking water to be free of contaminants than it is for it to contain extra minerals and come from an exotically-named spring. If you see bottled water labeled ‘raw’ on your supermarket shelf, though, consider it a marketing ploy, since bottled water is regulated by the FDA and has to undergo testing and whatever treatment necessary to ensure the water is safe.

If you’re concerned about drinking your local tap water, Moe recommends using a reverse osmosis filter system—which pushes water through a semi-permeable membrane that filters out potential contaminant particles—instead of turning to raw water.