Does your drinking water contain added fluoride? If so, keep it away from infants under the age of one. This directive was issued recently by an unlikely source: the American Dental Association (ADA).

In a November 9th email alert sent to all of its members, the ADA noted that “Infants less than one year old may be getting more than the optimal amount of fluoride if their primary source of nutrition is powdered or liquid infant formula mixed with water containing fluoride.” The ADA went on to advise: “If using a product that needs to be reconstituted, parents and caregivers should consider using water that has no or low levels of fluoride.”

The ADA issued this advice because babies exposed to fluoridated water are at high risk for developing dental fluorosis—a defect of the teeth which can result in staining and even corrosion of the enamel. In addition, on October 14th, the Food and Drug Administration stated that fluoridated water marketed to infants cannot claim to reduce the risk of cavities.

Dental fluorosis is not the only risk stemming from a baby’s exposure to fluoride. In the same week that ADA issued its advisory, an article in the British journal, The Lancet, reported that fluoride may damage a child’s developing brain. The Lancet review described fluoride, along with the rocket fuel additive perchlorate, as an “emerging neurotoxic substance” due to evidence linking fluoride to lower IQs in children, and brain damage in animals.

“Newborn babies have undeveloped brains, and exposure to fluoride, a suspected neurotoxin, should be avoided,” notes Hardy Limeback, a member of a 2006 National Research Council panel on fluoride toxicity, and former President of the Canadian Association of Dental Research.

Fluoride is linked with other health problems as well, including weakened bones, reduced thyroid activity, and possibly, bone cancer in boys, according to a recent report from a team of Harvard scientists, the US National Research Council and other recent studies.

While most of western Europe has abandoned the practice of adding fluoride to water, most US water supplies remain fluoridated. In addition, some brands of bottled water sold in the US, such as Nursery Water, specifically market fluoridated water for young babies.

A recent investigation by the Environmental Working Group (EWG) found that over-exposure to fluoride among infants is a widespread problem in most major American cities. EWG’s study found that, on any given day, up to 60% of formula-fed babies in US cities were exceeding the Institute of Medicine’s “upper tolerable” limit for fluoride.

“Water is supposed to be safe for everyone. Why add a chemical that makes it knowingly unfit for young children? The US should follow Europe’s lead and end fluoridation,” says Michael Connett, Project Director of the Fluoride Action Network.