A leading doctor has urged pregnant and lactating women to avoid drinking tap water containing fluoride because the mineral could damage the unborn baby’s brain.
Dr. Michael Greger, author of the How Not to Die series, said even parents who feed their children formula should avoid mixing it with fluoride-treated water, which he called a “presumed developmental neurotoxin.”
Speaking to DailyMail.com, she said: “Pregnant and lactating women and those with babies who have water mixed with infant formula should try to use unfluoridated water.”
His comments come days after a federal judge warned that fluoride, added to water systems to strengthen teeth and reduce cavities, posed an “unreasonable risk” to children’s brains.
And just a month after a 320-page government report found that fluoride in high concentrations could cause children’s IQs to drop by up to five points.
The map above shows states that do and do not participate in CDC’s My Water fluoride monitoring system.
The above shows the most recently known fluoride levels in U.S. county water systems.
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Fluoride is a naturally occurring mineral found in water, soil, and various foods. It has been added to public water systems since 1945 for its protective qualities, with the goal of reducing cavities and promoting overall good oral health.
The issue of fluoride in tap water is controversial because its introduction is considered one of the greatest public health achievements due to its effectiveness in reducing cavities in children.
About 80 years ago, scientists discovered that people whose water supplies naturally contained more fluoride also had fewer cavities. They determined that it was replacing minerals in teeth that were lost due to cavities and wear.
This triggered a push for more Americans to use fluoride, found in toothpaste, and to add the mineral to national drinking water supplies.
More than 200 million Americans drink water containing fluoride, or 75 percent of the population, more than any other country in the world.
And the CDC estimates it could reduce cavities by 25 percent and save about $6.5 billion each year in dental costs.
Most tap water in the U.S. contains fluoride at a level of about 0.7 milligrams per liter (mg/L), which is considered the “optimal” level.
But this figure is almost double what experts and studies have determined is the safe limit for pregnant women and babies: 0.4 mg/L.
The Environmental Protection Agency (EPA) says fluoride levels should not exceed 4 mg/L in water, warning that any higher level increases the risk of skeletal fluorosis or skeletal deformities.
The World Health Organization has established a limit of 1.5 mg/L.
An EPA spokesperson said the agency was reviewing how fluoride is regulated following a California court ruling this week that found fluoride posed a “hazard” to children’s health and said the EPA should conduct an investigation.
In his ruling, Judge Edward Chen said: ‘The scientific literature contained in the record provides a high level of certainty that a danger exists; Fluoride is associated with reduced IQ.
There has been controversy over fluoride in the water supply for years, with hundreds of communities voting against its use (above is a campaign sign from Kennebunk, Maine).
In an interview with this website, Dr. Greger urged the United States to follow the example of European countries like Germany, which do not fluoridate tap water.
But other nations, like the United Kingdom, are actually pressing ahead with plans to add more fluoride to tap water, making it available to millions more Britons.
British officials have said the scheme should be expanded to reduce the prevalence of cavities and improve dental health across the country.
Dr. Michael Greger warned pregnant women not to drink water that contains fluoride.
Filter pitchers and filter systems that claim to filter out fluoride are available online for up to $250. Manufacturers say they are up to 97 percent effective.
Experts say that when someone drinks water containing fluoride, the chemical enters the bloodstream and can then travel to the brain.
Hypotheses suggest that fluoride could interfere with the brain during development, causing children to have lower IQs.
It is also possible that it crosses the placental barrier and reaches the fetus, where it could also disrupt brain development.
Additionally, experts say it is possible for fluoride to enter breast milk and be transferred to the baby.
Dr. Greger said it was also possible that fluoride was affecting brain health in adults, but more studies were needed to determine this.
A study published this year in Open JAMA Network found that fluoride exposure during pregnancy was linked to increased behavioral problems in children.
The paper, which followed 229 pregnant women and their children, found that a 0.68 mg/L increase in urinary fluoride concentrations during pregnancy was associated with babies being almost twice as likely to have problems behavior, such as internalizing or externalizing problems.
And a report from the National Toxicology Program (NTP) warned of lower IQ among children exposed to high levels of fluoride based on 19 high-quality studies.
Many more counties in the US fluoridate their water than in any other country in the world, National Population Review data for 2024 reveals.
Dr Greger told DailyMail.com: ‘This is really about protecting pregnant mothers, breastfeeding mothers and babies who receive water mixed with infant formula.
‘The ideal would be to stop fluoridation to protect these vulnerable communities.
“They should just drink that purified water during pregnancy, breastfeeding and then when they mix formula, to get the best of both worlds until we (researchers) have figured out what’s going on.”
Dr. Greger said he had previously supported the consensus on adding fluoride to drinking water, and even considered those who argued otherwise “crazy.”
But while researching his latest book, published in 2020, he read a series of studies that convinced him that fluoridation might not be as safe as initially thought.
Dr. Greger, who lives in Virginia, still drinks local tap water that contains fluoride. It has a filter installed at home, but it serves to remove carbon and “improve the taste of the water.”
But he said whenever he meets a pregnant woman or a woman with a very young child, he urges them to avoid drinking tap water that contains fluoride.
The American Dental Association has been at the forefront of calls proclaiming that fluoride is safe and pushing for it to be added to local water supplies.
Advocacy groups like the Fluoride Action Network have been at the other end of the scale, arguing that claims that fluoride is safe have been exaggerated.
