fluoride

Is Fluoride Safe For Pregnant Women?

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What Does This Study Mean For You? 

Author: Dr. Stephen Chaney 

water faucetFluoridation of drinking water has always been controversial. On one side you have the dental and medical community who claim that fluoridation is a great public health advance. Their claim is that it strengthens teeth and prevents tooth decay with minimal risk to the public.

  • Although my dentist tells me that most of the “benefits” of fluoridation can be achieved with good dental hygiene. Fluoridation is just another example of the American public’s reliance on drugs and chemicals as a “quick fix” rather than taking the personal responsibility to make healthy lifestyle changes.

On the other side you have people who claim that fluoride is toxic at any level. Their claim is that there are many health issues with fluoridation that have been ignored by the dental and medical community. Their claims are that excess fluoride exposure increases the risk of:

  • Dental fluorosis (A discoloration of the teeth that is caused by overexposure to fluoride during childhood).
  • Bone fractures (Paradoxically, fluoride makes bones and teeth stronger, but it also makes them more fragile).
  • Arthritis.
  • Some types of cancer.

And in the middle are those who believe that fluoridation has both benefits and risks. They believe we should identify the risks, so we can advise people appropriately.

The study (AJ Main et al, JAMA Network Open, 2024; 7(5):e2411987) I will discuss today falls into this category. It also illustrates the difficulty in doing high-quality research on risks associated with fluoridation, which I will discuss.

How Was This Study Done?

clinical studyThe data for this study were obtained from the MADRES (Maternal and Developmental Risks from Environmental and Social Stressors) database. The women in this study were predominantly Hispanic women of low socioeconomic status who were recruited from prenatal clinics in Los Angeles serving predominantly medically underserved communities starting in 2015.

Maternal urinary fluoride (MUF) levels were measured during the third trimester of pregnancy between 2017 and 2020. The average MUF was 0.76 mg/dL, which is similar to the average MUF for women in this country. However, there was a broad range in MUF, so the women in this study were divided into quartiles based on their MUF score.

Their child’s score on the Preschool Behavior Checklist was measured at 36 months between 2020 and 2023. The Preschool Behavior Checklist is a 99-item questionnaire. The questionnaire measures 7 syndromes:

  • Emotionally reactive, anxious-depressed, somatic complaints (physical symptoms with no clear cause), withdrawal, sleep problems, attention problems, opposition-defiant problems, and aggressive behavior.

These symptoms are then used to calculate scores for two classes of problems:

  • Internalizing problems (anxiety, depression, somatic complaints, withdrawal, sleep problems).
  • Externalizing problems (attention problems, oppositional-defiant and aggressive behavior).

The questionnaire was also designed to provide scores for autism spectrum problems and ADHD problems.

Based on previous usage of the Preschool Behavior Checklist each of these scores can be divided into normal, borderline clinical problems, and clinical problems.

Is Fluoride Safe For Pregnant Women?

Pregnant CoupleWhen comparing women in the highest Maternal Urinary Fluoride (MUF) quartile in the third trimester to women in the lowest quartile, their children at age 36 months:

  • Were 83% more likely to have a combination of internalizing and externalizing behavior problems in the borderline clinical and clinical range.
  • Were 84% more likely to have a combination of internalizing and externalizing behavior problems in the clinical range.
  • Were 18.5% more likely to have symptoms characteristic of autism spectrum disorder.
  • Were 11.3% more likely to have anxiety symptoms.
  • Were 19.6% more likely to have somatic complaints (symptoms with no clear cause).

The authors concluded, “These findings suggest that prenatal fluoride exposure may increase risk of neurobehavioral problems among children living in optimally fluoridated areas in the US. These findings suggest there may be a need to establish recommendations for limiting exposure to fluoride during the prenatal period, a time when the developing brain is known to be especially vulnerable to injury from environmental insults.”

What Are The Strengths And Weaknesses Of This Study?

strengths and weaknessesThis is the first study of its kind in the United States. As such it should be regarded as a “proof of principle” study that needs to be confirmed by larger follow-up studies. However, it is fully consistent with two larger studies published in Canada and Mexico.

As a “proof of principle study, it does have some limitations, namely:

  • It was performed with a Hispanic population of low socioeconomic status and limited access to healthcare. It needs to be repeated with other population groups to see if it is generalizable to the general population. This is important because, if there is a need to make a recommendation to minimize fluoride intake during pregnancy, we need to know whether that recommendation applies to all women or just to certain high-risk groups.
  • It is an association study which does not prove cause and effect. Ideally, it should be followed by placebo-controlled intervention studies to prove cause and effect.
  • It is a very small study. Ideally, it should be followed by much larger studies.

However, it is unlikely that either of those follow-up studies will be done. It would cost hundreds of thousands of dollars to conduct large-scale studies – especially if they were placebo-controlled intervention studies. And with the dental and medical community fully convinced fluoridation has no risks, it would be very difficult to get that kind of money.

Even if that money were available, 73% of US communities have fluoridated water. Plus, most bottled beverages in the US are made with fluoridated water. So, it would not be easy to find a suitable control population for a placebo-controlled intervention study.

What Does This Study Mean For You?

water bottleAs I shared above, this is a “proof of principle” study. It suggests, but does not prove, fluoride exposure during pregnancy may increase the risk of neurobehavioral issues with your offspring.

However, I also realize that if you are pregnant or thinking of becoming pregnant and you spend any time on the internet, you are bombarded with all the things you must avoid if you want to have a healthy baby. I don’t want to add to your anxiety.

So, let’s assume the conclusions of this article might be true. What can you do?

With respect to drinking water, the answer is simple:

  • Drink filtered water or bottled water.
    • Most filtration systems remove fluoride (make sure yours does).
    • Many bottled waters do not contain fluoride. Read the label to be sure:
      • If it is bottled tap water, it probably contains fluoride.
      • If it is spring water, the fluoride would have to be added and would appear on the label.
      • If it is filtered or distilled water, it does not contain fluoride.
  • Since municipal water supplies often contain low levels of other contaminants, this is a good idea even if you aren’t pregnant.

With respect to bottled beverages, the answer is more complex.

  • The list of beverages made with fluoridated municipal water is a long one. It includes sodas, energy drinks, teas, fruit juices “made from concentrate”, and much more.
  • However, you already know that most of these beverages are bad for you because they contain added sugar and/or a long list of artificial ingredients. Substituting filtered water or fluoride-free bottled water for them is a good idea whether you are pregnant or not.

The Bottom Line

A recent study looked at the correlation between fluoride intake during pregnancy and neurobehavioral issues in the children at 36 months.

When comparing pregnant women with the highest fluoride intake to women with the lowest fluoride intake, their children at age 36 months:

  • Were 83% more likely to have behavior problems.
  • Were 18.5% more likely to have symptoms characteristic of autism spectrum disorder.
  • Were 11.3% more likely to have anxiety symptoms.
  • Were 19.6% more likely to have somatic complaints (symptoms with no clear cause).

The authors concluded, “These findings suggest that prenatal fluoride exposure may increase risk of neurobehavioral problems among children living in optimally fluoridated areas in the US. These findings suggest there may be a need to establish recommendations for limiting exposure to fluoride during the prenatal period, a time when the developing brain is known to be especially vulnerable to injury from environmental insults.”

For more details on this study and what it means for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

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About The Author 

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.

Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”.

Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

For the past 45 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

Are Toxic Chemicals Lowering Our IQ?

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Is Chemical Brain Drain A Pandemic?

 Author: Dr. Stephen Chaney

In a past issue of “Health Tips From the Professor” I examined the evidence suggesting that toxic chemicals in the home could cause childhood asthma. That is alarming because asthma can predispose individuals to other diseases and affects quality of life.

Confused ChildBut, what if that were only the tip of the iceberg? For example, a recent headline stated: “More Toxic Chemicals [In Our Environment] Are Damaging Children’s Brains”. If that headline is true, it’s downright scary.

The authors of this study suggested that toxic chemicals which are abundant in our environment can cause decreases in IQ and aggressive or hyperactive behavior in children – and that those changes may be permanent.

The Study Behind The Headlines

The paper that generated the headlines (Grandjean & Landrigan, The Lancet Neurology, 13: 330-338, 2014) was a review of the literature, not an actual clinical study.

Based on published clinical studies, the authors identified 12 chemicals commonly found in the environment as developmental neurotoxins (toxins that interfere with normal brain development) based. [If you would like to find out what those “Dirty Dozen” chemicals are and where they are found, click here.]

This finding compares with 6 developmental neurotoxins that they were able to identify in a similar study in 2006.

The authors were not claiming that the number or amount of toxic chemicals changed between 2006 and 2014. They were saying that science has advanced to the point where we can classify six more chemicals that have been in our environment for years as developmental neurotoxins.

Even more worrisome, the authors postulate that many more environmental neurotoxins remain undiscovered.

Are Toxic Chemicals Lowering Our IQ?

To answer that question, you need to look at some of the studies they cited in their review. For example:

  • Elevated blood lead levels in children are associated with as much as a 7 point decrease in IQ (Lamphear et al, Environmental Health Perspectives, 113: 894-899, 2005).
  • Elevated fluoride levels in drinking water are also associated with as much as a 7 point decrease in IQ (Choi et al, Environmental Health Perspectives, 120: 1362-1368, 2012).

The effects of many of the toxic chemicals on IQ were difficult to quantify, but the authors estimated that exposure of US children to just 3 of the chemicals (lead, methymercury and organophosphate pesticides) was sufficient to lower their average IQ by 1.6 points.

What Are The Potential Consequences?

The authors spoke of the environmental neurotoxins they identified as representing a “silent pandemic of a chemical brain drain” that could cost the US economy billions of dollars.

One of the blog posts I read on this topic summarized the consequences in a very graphic manner. It said:

If one child’s IQ is reduced by 5 points, it doesn’t appear to make a big difference.  For example, that child might be:

  • A little slower to learn
  • A little shorter of attention
  • A little less successful at tests and at work

That might result in $90,000 in lost lifetime earnings

However, if the average IQ of every child in the US were decreased by 5 points, the effect becomes significant:

  • Only half as many members of the next generation would be “intellectually gifted”.
  • Twice as many of the next generation would be “intellectually impaired”
  • Lost productivity could be in the billions

Of course, statements like that are a bit over the top. Drs. Grandjean and Landrigan did not claim that the net effect of the chemicals they identified was a 5 point drop in IQ. Nor did they claim that all US children were affected equally.

Still, it’s enough to make you think.

Are Toxic Chemicals Causing Behavior Problems?

Angry boy portraitThe authors cited numerous studies linking the chemical neurotoxins they identified to aggression and hyperactivity. But perhaps the most compelling reason to suspect that environmental chemicals may be affecting brain development is the spiraling incidence of developmental disorders such as autism and ADHD. For example:

  • Autism has increased by 78% since 2007 and now affects 1 of 88 eight year old children.
  • ADHD has increased by 43% since 2003 and now affects 11% of children age 4-17.

Some of this increase could be due to better diagnosis of these conditions, but nobody believes that all of it is due to improved diagnosis. The authors claim that much of this increase is likely due to environmental exposure to the kinds of developmental neurotoxins they identified.

Is The Science Solid?

This is a difficult area of research. You can’t do the gold standard double-blind, placebo-controlled clinical trial. Nobody in their right mind would give one group of children toxic chemicals and the other group a placebo.

The studies cited in this paper were mostly population studies. Basically this means that they compared children with exposure to certain toxic chemicals to a control group that was as similar as possible to the first group except that their exposure to the toxic chemicals was less.

The limitation of this kind of study is obvious. We are usually comparing children from different locations or of different backgrounds. We almost never know if we have controlled for all possible variables so that the groups are truly identical.

As a consequence it becomes important to ask how many studies come to the same conclusion. For some of the toxic chemicals, such as lead, methymercury and organophosphate pesticides, the weight of evidence is very strong. For some of the newer additions to their list of developmental neurotoxins, it is pretty clear that the chemicals have neurotoxic properties, but the significance of those effects on the developing human brain are hard to quantify at this point.

The Bottom Line:

1)     A recent review claims that there is a good scientific basis for classifying at least 12 environmental chemicals as developmental neurotoxins that are likely to reduce IQ and contribute to behavioral problems in US children. [If you would like to find out what those “Dirty Dozen” chemicals are and where they are found, click here.]

2)     The science behind the claims in this review is solid, but not iron-clad.

3)     However, there are times when we need to simply ask ourselves: “What if it were true?” The consequences of lowered IQ and developmental behavioral problems are so significant that it may not make sense to wait until we have unassailable scientific evidence before we act.

4)     We all need to be guardians of our personal environment. But, it is not easy. The “Dirty Dozen” chemicals identified in this study come from many sources:

  • Some are industrial pollutants. For those, we need lobby for better environmental regulation.
  • Some are persistent groundwater contaminants. For those we need to drink purified water whenever possible.
  • Some are insecticides and herbicides used in agriculture. For those we need to buy organic, locally grown produce when feasible.
  • Some are found in common household products and furnishings. For those we need to become educated label readers and use non-toxic products in our home whenever possible.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

The Dirty Dozen

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Environmental Toxins That Affect Brain Development

 Author: Dr. Stephen Chaney

 In a recent review, Drs. Grandjean and Landrigan (The Lancet Neurology, 13: 330-338, 2014) identified 12 toxic chemicals which are abundant in our environment and are developmental neurotoxins.

These are all chemicals that damage brain development. They can cause decreases in IQ and aggressive or hyperactive behavior in children – and that those changes may be permanent.

Let’s look at these developmental neurotoxins and where they are found.

The Dirty Dozen

In their review Grandjean & Landrigan identified 6 developmental neurotoxins that were known in 2006, and 6 more chemicals that have been confirmed to be developmental neurotoxins between 2006 and 2023.

Developmental Neurotoxins Known in 2006 and their sources:

  • Lead
    • Main Sources: paint, gasoline, solder and consumer products such as toys & jewelry
    • Current status: Lead has been banned in paint since 1978 and from gasoline since 1996. Millions of houses still contain lead paint. Other current sources are inexpensive toys and costume jewelry imported from China and other countries without tight regulations.
    • The EPA estimates that 1 million children in the US are affected by elevated lead levels.
  • Methylmercury
    • Main Sources: discharges into air & water from coal-burning power plants, mining, pulp & paper industries.
  • Polychorinated biphenyls (PCBs)
    • Main Sources: transformers and many commercial products
    • Current status: Banned in 1979, but continues to be a common environmental contaminant because this group of chemicals is very long-lived.
  • Arsenic:
    • Main Sources: extraction of metals from rock (smelting), algaecides, herbicides, pesticides and pressure-treated wood.
    • Current status: Pressure treated wood banned in 2003 for residential use. Still found in some playgrounds and older buildings.
  • Toluene:
    • Main Sources: gasoline. It is also a solvent for paints, paint thinners, spot removers, adhesives, antifreeze, & some consumer products like fingernail polish removers.
    • Current status: Common in consumer products. Read labels and make sure windows are open if you use.

Developmental Neurotoxins Identified Since 2006 and their sources:

  • Manganese
    • Main Sources: municipal wastewater discharge, emissions generated during alloy, steel & iron production, emissions from burning of fuel additives
  • Flouride
    • Main Sources: naturally elevated in groundwater in certain regions, added to municipal water supply, most bottled beverages and toothpaste.
    • The American Academy of Pediatrics has warned that children drinking fluoridated water, fluoridated beverages, using fluoridated toothpaste and receiving fluoride treatments for their teeth may be receiving excess fluoride.
  • Chlorpyrifos
    • Main Sources: insecticide
    • Current status: Banned for use in homes in 2001. Still one of the most widely used insecticides in agriculture.
  • DDT
    • Main Sources: insecticide
    • Current status: Banned for use in this country in 1972. DDT and its breakdown products still found in our water supply. DDT still in use in agriculture and insect control in some countries.
  • Trichloroethylene (TCE)
    • Main Sources: widely used in dry cleaning fabrics, the textile industry and metal degreasing
    • Current status: Found in groundwater due to discharge from factories and dry cleaners.
  • Polybrominated diphenyl ethers (PBDEs)
    • Main Sources: flame retardants – used in building materials, electronics, mattresses & household furniture, plastics, polyurethane foams & textiles.
    • Current status: Readily leached into the environment. Found in dust, water, food & human breast milk

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

 

Health Tips From The Professor