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The Harmful Effects of Fluoride


Fluoride is a naturally occurring mineral that is added to water supplies and dental products for the purpose of preventing tooth decay. It has been used for many years as a public health measure to improve dental health. However, over the last few decades, debate has grown over the safety of fluoride. This has resulted in a growing body of scientific evidence that suggests that fluoride can have potentially harmful effects on human health.

In this article, we will examine the evidence for the health risks associated with the consumption of fluoride.


Fluoride in Drinking Water

Approximately three-quarters of the population of the United States consume water that has been artificially fluoridated. The addition of fluoride to both water and toothpaste is widely considered to be a beneficial public health measure, as it is considered to help reduce the incidence of dental decay by strengthening the enamel on the teeth.

Fluoride has been used in water supplies for over 70 years in many countries around the world, including the United States, Canada, Australia and the United Kingdom (McLaren & Waldbott, 1978). In the United States, the Centers for Disease Control and Prevention (CDC) recommends adding fluoride to public water supplies in order to reduce the incidence of cavities and deem that the fluoridation of water is one of the ten most significant public health accomplishments of the twentieth century.

People in countries that use fluoridated water do not necessarily have better dental health than those in countries that do not use fluoridated water. There has been a decrease in the prevalence of dental issues without the implementation of fluoride in their water supply.

Despite the widespread use of fluoride, it has been a topic of debate for many years with growing evidence that suggests that it does have negative health effects. Studies have linked fluoride exposure to a variety of health problems, including bone problems, neurological problems and hypothyroidism just to name a few.


Developmental Neurotoxin

One of the best reasons to consider avoiding adding fluoride is for the sake of of your brain because it is a developmental neurotoxin. Neurotoxins are substances that are poisonous, or otherwise destructive to the tissues in the brain, spinal cord and nervous system. In particular, developmental neurotoxins are those that affect the brain during the most vulnerable stages of life, such as before birth and during early childhood. This was highlighted in a systematic review of studies published in ‘The Lancet,’ one of the most prestigious medical journals, which recommended that fluoride be classified as a developmental neurotoxin.

Increased levels of neurotoxins have been linked to a range of cognitive impairments, including attention deficit disorder, a decrease in IQ points and disruptive behaviours.

Studies have found that fluoride exposure may be associated with an increased risk of lower IQ scores in children (Choi et al., 2012). In addition, fluoride exposure has been linked to an increased risk of neurobehavioral problems such as hyperactivity and attention deficit disorder (ADHD) (Guha-Thakurta et al., 2018).

Harvard School of Public Health and China Medical University conducted an analysis of 27 studies to evaluate the impact of fluoride on the intelligence quotient of children. It has been found that there is a direct relationship between the amount of fluoride present in the environment and its effects on the development of the brain. Children who resided in areas with high levels of fluoride in the water supply had IQ scores that were lower than those of children living in areas with low levels of fluoride.


Alzheimer’s Disease

The Fluoride Action Network, a registered non-profit organization, provides a list of studies which demonstrate that fluoride facilitates the entry of aluminum into the brain. This phenomenon was first discovered in the 1970s, when autopsies of Alzheimer's patients revealed higher than normal concentrations of neurotoxic aluminum in their brains.

Recent research has suggested that the potential relationship between aluminum and Alzheimer's disease may be linked to the presence of fluoride in the body. When aluminum comes into contact with fluoride, it is converted into aluminum fluoride, which is able to bypass the blood-brain barrier and enter the brain. The presence of aluminum fluoride in the brain strongly correlates to the potential risk of Alzheimer's disease.



Fluoridated drinking water nearly doubles the risk of developing hypothyroidism (underactive thyroid). Several studies have found that fluoride exposure may be associated with an increased risk of thyroid problems, particularly in postmenopausal women (Li et al., 2018).

The binding of fluoride with iodine receptors in the thyroid displaces iodine. When there is an insufficient amount of iodine available, the thyroid gland is unable to synthesize the thyroid hormones, which is certainly not good news for the brain and its functioning.

Thyroid disorders can cause a range of cognitive and mental health issues, such as brain fog, memory loss, lack of focus, depression and anxiety.

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Nervous System Degeneration

Furthermore, research has shown that fluoride when it crosses the blood-brain barrier, can lead to degeneration in certain regions of the brain, including the hippocampus, neocortex and cerebellum.

The hippocampus is critical for learning, emotional regulation and the deactivation of the stress response that is the area of the brain responsible for memory.

The neocortex is the most highly evolved area of the brain that is responsible for processing sensory perception, conscious thought and language abilities.

The cerebellum is responsible for coordinating movements and maintaining balance.


Bone Problems

Another area of concern is the potential for fluoride to damage the bones and teeth. Fluoride can accumulate in bones and teeth over time, and high levels of fluoride intake have been linked to an increased risk of skeletal fluorosis, a condition characterized by pain and stiffness in the bones and joints. Fluoride has also been shown to weaken bones and increase the risk of fractures, particularly in older adults.

Numerous studies have linked fluoride exposure to an increased risk of bone fractures and osteoporosis (Fomon et al., 1985; Danielson et al., 1992). One study even found that fluoride levels in drinking water were associated with an increased risk of hip fractures in elderly women (Danielson et al., 1992).

Lastly, fluoride exposure has been linked to an increased risk of bone diseases such as fluorosis. Fluorosis is a condition in which the bones become weak and brittle due to an excessive amount of fluoride in the body (U.S. Department of Health and Human Services, 1991). It can lead to pain and deformities in the bones and joints.


In conclusion, the evidence suggests that fluoride has a range of harmful effects on human health. It is important to carefully weigh these potential risks and consider alternative approaches to promoting dental health and overall well-being.


Choi, A. L., Sun, G., Zhang, Y., Grandjean, P., & et al. (2012). Developmental fluoride neurotoxicity: a systematic review and meta-analysis. Environmental Health Perspectives, 120(10), 1362–1368.

Danielson, C., Lyon, J. L., Egger, M., & Goodenough, G. K. (1992). Hip fractures and fluoridation in Utah’s elderly population. Journal of the American Medical Association, 268(4), 746–748.

Fomon, S. J., Ekstrand, J., Ziegler, E. E., Nelson, S. E., & et al. (1985). Fluoride intake and prevalence of dental fluorosis: trends in fluoride intake with special attention to infants. Journal of Dental Research, 64(1), 890–897.

Guha-Thakurta, N., Guha, M., & Mathur, K. (2018). The effect of fluoride on neurological development in children. Reviews in Environmental Health, 33(1), 1–11.

Li, X., Wang, X., Zhang, F., & Chen, S. (2018). Fluoride and its effects on human health. International Journal of Environmental Research and Public Health, 15(11), 2381.

McLaren, G. S., & Waldbott, G. L. (1978). Fluoridation: the great dilemma. Coronado Press, Lawrence, Kansas.

Environmental Health Perspectives. (2014). Fluoride in Drinking Water: A Scientific Review of EPA's Standards. Retrieved from

National Research Council. (2006). Fluoride in Drinking Water: A Scientific Review of EPA's Standards. Washington, DC: The National Academies Press.

World Health Organization. (2015). Fluoride and Oral Health. Retrieved from

U.S. Department of Health and Human Services. (1991). Review of fluoride benefits and risks. Report of the Ad Hoc Committee on Fluoride of the Council on Dental Therapeutics, American Dental Association.

This content is accurate and true to the best of the author’s knowledge and does not substitute for diagnosis, prognosis, treatment, prescription, and/or dietary advice from a licensed health professional. Drugs, supplements, and natural remedies may have dangerous side effects. If pregnant or nursing, consult with a qualified provider on an individual basis. Seek immediate help if you are experiencing a medical emergency.

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