Dr. Joseph Mercola
A recently-published Harvard University meta-analysis funded by the National Institutes of Health (NIH) has concluded that children who live in areas with highly fluoridated water have "significantly lower" IQ scores than those who live in low fluoride areas.
In a 32-page report that can be downloaded free of charge from Environmental Health Perspectives, the researchers said:
A recent report from the U.S. National Research Council (NRC 2006) concluded that adverse effects of high fluoride concentrations in drinking water may be of concern and that additional research is warranted. Fluoride may cause neurotoxicity in laboratory animals, including effects on learning and memory ...
To summarize the available literature, we performed a systematic review and meta-analysis of published studies on increased fluoride exposure in drinking water and neurodevelopmental delays. We specifically targeted studies carried out in rural China that have not been widely disseminated, thus complementing the studies that have been included in previous reviews and risk assessment reports ...
Findings from our meta-analyses of 27 studies published over 22 years suggest an inverse association between high fluoride exposure and children's intelligence ... The results suggest that fluoride may be a developmental neurotoxicant that affects brain development at exposures much below those that can cause toxicity in adults ...
Serum-fluoride concentrations associated with high intakes from drinking-water may exceed 1 mg/L, or 50 Smol/L, thus more than 1000-times the levels of some other neurotoxicants that cause neurodevelopmental damage. Supporting the plausibility of our findings, rats exposed to 1 ppm (50 Smol/L) of water-fluoride for one year showed morphological alterations in the brain and increased levels of aluminum in brain tissue compared with controls ...
In conclusion, our results support the possibility of adverse effects of fluoride exposures on children's neurodevelopment. Future research should formally evaluate dose-response relations based on individual-level measures of exposure over time, including more precise prenatal exposure assessment and more extensive standardized measures of neurobehavioral performance, in addition to improving assessment and control of potential confounders.
Studies Have Repeatedly Linked Fluoride to Reduced IQ and Brain Damage
There are so many scientific studies showing the direct, toxic effects of fluoride on your body, it's truly remarkable that it's NOT considered a scientific consensus by now. Despite the evidence against it, fluoride is still added to 70 percent of U.S. public drinking water supplies.
It amazes me that the medical (and dental) communities are so stubbornly resistant to connect the dots when it comes to the skyrocketing increase of cognitive decline in adults and behavioral issues in children (ADD, ADHD, depression and learning disabilities of all kinds). In fact, there have been more than 23 human studies and 100 animal studies linking fluoride to brain damage. Fluoride can also increase manganese absorption, compounding problems, since manganese in drinking water has also been linked to lower IQ in children.
Reported effects of fluoride on your brain include:
• Reduction in nicotinic acetylcholine receptors
• Damage to your hippocampus
• Formation of beta-amyloid plaques (the classic brain abnormality in Alzheimer's disease)
• Reduction in lipid content
• Damage to purkinje cells
• Exacerbation of lesions induced by iodine deficiency
• Impaired antioxidant defense systems
• Increased uptake of aluminum
• Accumulation of fluoride in your pineal gland
Six Facts You Need to Know About Water Fluoridation
Harmful Effects Have Been Known for Half a Century
What is perhaps most surprising is that the harmful effects of fluoride have been known by conventional medical organizations for over half a century. For example, the Journal of the American Medical Association (JAMA) stated in their Sept. 18, 1943 issue that fluorides are general protoplasmic poisons that change the permeability of the cell membrane by certain enzymes. And, an editorial published in the Journal of the American Dental Association on Oct. 1, 1944, stated:
Drinking water containing as little as 1.2 ppm fluoride will cause developmental disturbances. We cannot run the risk of producing such serious systemic disturbances. The potentialities for harm outweigh those for good.Part of the problem is that it's an accumulative toxin that, over time, can lead to significant health problems that are not immediately linked to fluoride over-exposure. In a 2005 paper entitled "Fluoride -- A Modern Toxic Waste," Lita Lee, Ph.D. writes:
Yiamouyiannis' book, Fluoride, The Aging Factor, documents the cumulative effect of tissue damage by fluoride, commonly seen as aging (collagen damage), skin rashes and acne, gastrointestinal disorders, and many other conditions, including osteoporosis. The U.S. Center for Disease Control and the Safe Water Foundation reported that 30,000 to 50,000 excess deaths occur in the United States each year in areas in which the water contains only one ppm fluoride ...Studies have shown that fluoride toxicity can lead to a wide variety of health problems, including:
Fluoride suppresses the immune system: Fluoride inhibits the movement of white blood cells by 70 percent, thereby decreasing their ability to reach their target. Yiamouyiannis cites 15 references in his pamphlet, Lifesavers Guide to Fluoridation, that document immunosuppressive effects of as little as 10 percent of the amount of fluoride used in fluoridated water ... Immunosuppressive effects run the gamut, from a cold that won't go away to increased risk of cancer and other infectious diseases.
• Increased lead absorption
• Disrupts synthesis of collagen
• Hyperactivity and/or lethargy
• Muscle disorders
• Thyroid disease
• Bone fractures
• Lowered thyroid function
• Bone cancer (osteosarcoma)
• Inactivates 62 enzymes and inhibits more than 100
• Inhibited formation of antibodies
• Genetic damage and cell death
• Increased tumor and cancer rate
• Disrupted immune system
• Damaged sperm and increased infertility
Suppressed Science: Fluoride Link to Cancer
Long-lost research linking fluoride to cancer has resurfaced in a Dutch film clip featuring Dr. Dean Burk, who in 1937 cofounded the U.S. National Cancer Institute (NCI) and headed its cytochemistry department for more than 30 years. In the taped interview, he equates water fluoridation to "public murder," referring to a study that had been done on the 10 largest U.S. cities with fluoridation compared to the 10 largest without it. The study demonstrated that deaths from cancer abruptly rose in as little as a year or two after fluoridation began. This and other studies linking fluoride to cancer were government-ordered but were quickly buried once fluoride was found to be linked to dramatic increases in cancer.
Impact of fluoride on neurological development in childrenJuly 25, 2012 — For years health experts have been unable to agree on whether fluoride in the drinking water may be toxic to the developing human brain. Extremely high levels of fluoride are known to cause neurotoxicity in adults, and negative impacts on memory and learning have been reported in rodent studies, but little is known about the substance’s impact on children’s neurodevelopment. In a meta-analysis, researchers from Harvard School of Public Health (HSPH) and China Medical University in Shenyang for the first time combined 27 studies and found strong indications that fluoride may adversely affect cognitive development in children. Based on the findings, the authors say that this risk should not be ignored, and that more research on fluoride’s impact on the developing brain is warranted.
The study was published online in Environmental Health Perspectives on July 20, 2012.
The researchers conducted a systematic review of studies, almost all of which are from China where risks from fluoride are well-established. Fluoride is a naturally occurring substance in groundwater, and exposures to the chemical are increased in some parts of China. Virtually no human studies in this field have been conducted in the U.S., said lead author Anna Choi, research scientist in the Department of Environmental Health at HSPH.
Even though many of the studies on children in China differed in many ways or were incomplete, the authors consider the data compilation and joint analysis an important first step in evaluating the potential risk. “For the first time we have been able to do a comprehensive meta-analysis that has the potential for helping us plan better studies. We want to make sure that cognitive development is considered as a possible target for fluoride toxicity,” Choi said.
Choi and senior author Philippe Grandjean, adjunct professor of environmental health at HSPH, and their colleagues collated the epidemiological studies of children exposed to fluoride from drinking water. The China National Knowledge Infrastructure database also was included to locate studies published in Chinese journals. They then analyzed possible associations with IQ measures in more than 8,000 children of school age; all but one study suggested that high fluoride content in water may negatively affect cognitive development.
The average loss in IQ was reported as a standardized weighted mean difference of 0.45, which would be approximately equivalent to seven IQ points for commonly used IQ scores with a standard deviation of 15.* Some studies suggested that even slightly increased fluoride exposure could be toxic to the brain. Thus, children in high-fluoride areas had significantly lower IQ scores than those who lived in low-fluoride areas. The children studied were up to 14 years of age, but the investigators speculate that any toxic effect on brain development may have happened earlier, and that the brain may not be fully capable of compensating for the toxicity.
“Fluoride seems to fit in with lead, mercury, and other poisons that cause chemical brain drain,” Grandjean says. “The effect of each toxicant may seem small, but the combined damage on a population scale can be serious, especially because the brain power of the next generation is crucial to all of us.”
* This sentence was updated on September 5, 2012.
Read a September 2012 statement by the authors.
** Learn more about the IQ measurements by HSPH’s Anna L. Choi and Philippe Grandjean in response to a letter to the journal published in the March 2013 (Vol. 121, No. 3) Environmental Health Perspectives.
– Marge Dwyer