April 10, 2000 (Atlanta) -- Raise a glass of good, old-fashioned tap water to toast this news: when it comes to water, bottled may not be better. Bottled water frequently contains less than the recommended levels of fluoride, which could cause a rise in tooth decay among children. And bottled water is not as pure as many people think, according to a recent report.
Experts writing in the March issue of the journal Archives of Family Medicine say the same standards should apply to both tap and bottled water, because bottled water is more and more often used as a substitute for tap water.
For the study, researchers took tap water samples from four processing plants in Cleveland and compared them with five types of bottled water samples, measuring fluoride and bacteria levels in both.
Only 5% of the bottled water purchased in Cleveland fell within the fluoride range recommended by the state, and nearly 90% of the bottled water samples contained less than a third of the fluoride recommended.
Not only did 100% of the tap water samples fall within the recommended range, but all of it was within 0.04% of hitting the state's optimal fluoride level mark -- 1.0 mg of fluoride per liter.
And while two-thirds of the bottled water samples did indeed have a lower bacterial count than the tap water samples, 25% had a whopping 10 times more bacteria. Bacteria in tap water samples varied only slightly.
Even though the EPA recently required that local water systems regularly report the quality of the local tap water to the community, no similar proposals requiring bottled water to report its quality on its label are on the table, researchers note.
"Bottled water should have to meet the same standards as tap water," says James Lalumandier, DDS, MPH, a professor of dentistry at Case Western Reserve University in Cleveland. "But the U.S. Food and Drug Administration doesn't require bottled water to contain enough fluoride to prevent tooth decay." Lalumandier says this could cause tooth decay to increase, particularly among children.
"Even though sugar consumption is rising, tooth decay is decreasing," he continues. "And most researchers credit fluoride for the decline. But if more people replace tap water with bottled water, tooth decay is likely to increase."
Lalumandier also says bacterial contamination can cause serious illness, and doctors agree. "In 1993, contaminated city water sickened over 400,000 local citizens," says Fernando Carballo, MD, a gastroenterologist in Milwaukee. "Now it's the first thing people think of if they get cramps or diarrhea. A lot of children and older adults were affected."
Home water filtering systems may be an option if you're worried about bacteria in your tap water but still want the fluoride, although some systems may filter out the fluoride, Carballo tells WebMD.
"Distilled water filtration systems remove a lot of fluoride, but charcoal or carbon systems don't," says Lalumandier. And he says because fluoride supplements are recommended for kids without fluoridated tap water, "supplements may be a good idea for kids who drink mostly bottled water."
- Fluoride and bacteria content of bottled water varies widely.
- Producers of bottled water are not required to meet the same standards that are applied to tap water.
- In some cases, bottled water was found to contain 10 times the level of bacteria found in tap water.