Fluoride, a naturally occurring mineral, is commonly added to drinking water and dental products to prevent tooth decay. However, whether fluoride is a neurotoxin or not remains a contentious issue, with numerous studies highlighting potential risks, particularly in children and unborn babies. In this blog I explore the evidence surrounding fluoride neurotoxicity, examine various research findings and the ongoing debate over water fluoridation.
If this evidence is concerning to you, you may want to look at reducing your fluoride exposure, especially if you are pregnant, by using purified, fluoride-free drinking water, and fluoride-free dental products.
The Origins of Fluoride Use
Fluoride’s journey into public health began in the 1940s when scientists found it helped reduce cavities. Community water fluoridation in the USA became a standard practice, credited with significantly reducing dental caries. However, as fluoride use became widespread, concerns about its potential adverse effects also grew. (Some people claim that fluoridation began as a scheme to rid industry of a toxic waste.)
The Current State of Fluoridation
Currently most European countries do not fluoridate their water supplies. A few major metropolitan areas in the USA also do not fluoridate their water, of which Portland, OR is the most notable. About 73% of the people in the USA that live with access to community water systems have fluoridated water. Overall, 64% of the USA population has access to fluoridated water, with private wells making up most of the difference.
In other developed countries about 7% of the population has fluoridated water. Other countries that have more than half of their population with fluoridation are Australia (80%), Chile (70%), the Irish Republic (73%), Israel (70%), and New Zealand (61%). So, the USA and a handful of other countries have adopted fluoridation of public water supplies, while most of the global population goes without, including many developed countries that supply fluoride to their population through dental products. So, we see that water fluoridation is a still a contentious issue.
Research on Fluoride Neurotoxicity
Is fluoride a neurotoxin? That is a key research question that has been investigated in animals, in pregnancy-child studies, and other population studies. Here are some key research papers that indicate that fluoride indeed harms the brain and cognitive function of people.
1. Cognitive Impairment in Children in Canada:
A landmark study published in JAMA Pediatrics (2019) investigated the association between women’s fluoride exposure during pregnancy and IQ scores in their children. The study, which analyzed data from 512 mother-child pairs in Canada, found that higher fluoride levels in pregnant women were associated with lower IQ scores in their children, especially in boys. This research raised alarms about the potential developmental neurotoxicity of fluoride, particularly during critical periods of brain development during pregnancy.
2. Cognitive Impairment in Children in Los Angeles, USA:
From the same MADRES study as the landmark study above, but with the group in Los Angeles, 229 mother-child pairs were studied with the study just published in JAMA Network Open on May 20, 2024. An increase in maternal fluoride exposure lead to a doubling of the risk of the child having neurobehavioral problems that were in or near the clinical range when they were 3 years old.
3. Cognitive Impairment in Children in Mexico:
In the ELEMENT project 299 mother-child pairs were followed. An increase of 0.5 mg/L for the maternal fluoride exposure while pregnant was associated with a 2.5 point decline in IQ in their children when they were 6-12 years old.
What is especially important about these studies’ results is that the exposure range in which damage occurred to children was within the normal range of fluoride intake in pregnant women. So, these results together suggest there is a need to recommend limiting fluoride exposure during pregnancy.
4. Meta-Analysis of IQ Studies:
A meta-analysis published back in 2012 in Environmental Health Perspectives reviewed 27 studies on fluoride exposure and neurodevelopment. The analysis found a consistent association between high fluoride exposure and reduced IQ levels in children. These findings suggest that fluoride, even at low exposure levels commonly found in fluoridated water, may adversely affect children’s brain development. These finding, of course, do not include the more recent studies that confirm what was seen more than a decade ago.
5. Animal Studies:
Animal studies have also provided insights into fluoride’s neurotoxic potential. Research on animals showed that fluoride exposure can lead to brain changes and behavior problems in rats. It changes both the structure of the brain as well as functional deficits. These animal models help us figure out how fluoride might affect the human brain, such as oxidative stress and interference with neurotransmitter function. The levels of fluoride used in animal studies is much higher than what people are exposed to, in order to make the changes more obvious and easier to find.
Biological Mechanisms of Fluoride Neurotoxicity
Understanding how fluoride affects the brain is crucial to assessing its risks. Several mechanisms have been proposed:
Oxidative Stress:
Fluoride exposure has been linked to increased oxidative stress in the brain. This can damage neurons and impair their function, potentially leading to cognitive deficits. Studies have shown that antioxidants like selenium can reduce some of these harmful effects, suggesting that oxidative stress plays a significant role in fluoride neurotoxicity.
Disruption of Thyroid Function:
Fluoride can interfere with iodine uptake, which is essential for thyroid hormone production. Thyroid hormones are critical for brain development, and if they get disrupted during pregnancy and early childhood it can have long-lasting effects on cognitive function.
Inhibition of Enzymes:
Fluoride has been shown to inhibit several enzymes in the brain, including those involved in energy production and antioxidant defense. This inhibition can lead to cellular dysfunction and nerve degeneration.
Public Health and Policy Implications
Because of these potential risks, there is a big debate about adding fluoride to water. Some organizations, like the International Academy of Oral Medicine and Toxicology (IAOMT), oppose water fluoridation, saying it could be harmful. They argue that it’s hard to control how much fluoride people get from water. Babies, because of their small size, drinking formula from fluoridated water would get a large dose while adults would get a relatively small dose. People who drink a lot of water get way more fluoride than others.
In contrast, many public health agencies maintain that the benefits of water fluoridation for dental health outweigh the risks. They argue that the evidence for fluoride neurotoxicity is not conclusive and that current fluoride levels in drinking water are safe for most people.
Who do you trust? A lot of whose science you believe these days comes down to a question of trust. Who do you trust? Can you follow the money trail? Money seems to have a corrupting influence on much of society, including scientific findings.
The American Dental Association and other public health agencies have not condemned mercury amalgam fillings either, which calls their judgment of what is good for the people into question.
So.
Recommendations for Reducing Exposure
If you’re worried about fluoride, here are some steps you can take to reduce your exposure:
Use Fluoride-Free Water:
Consider drinking bottled water or installing a water filtration system that removes fluoride, especially if you are pregnant or have young children.
Limit Fluoride-Containing Dental Products:
Use fluoride-free toothpaste and mouthwash, particularly for children who might swallow these products. Consider using essential oils for cleaning your teeth and gums. Read this article for more on the benefits of this approach.
Stay Informed:
Keep up with the latest research on fluoride and its health effects. As scientists learn more, they may provide new insights into the risks and benefits of fluoride.
Conclusion
Fluoride’s possible harm to the brain is a complicated and debated topic. While fluoride may help prevent tooth decay, new research suggests it might also pose risks to brain development, especially in children. Balancing these benefits and risks is a challenge for health policy.
Understanding the evidence and how fluoride might affect the brain can help you make better choices about what water you drink and dental products you use. It is important for you to understand the risks and take action for yourself to mitigate the potential risks in your particular situation. If you are pregnant or responsible for infants and young children the risk of developmental damage is much greater, so greater caution should be exercised in such situations to protect brain health and development.
