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Harvard Study: Fluoride Lowers Children’s Intelligence By 7 IQ Points

The study [click for abstract] was published online in Environmental Health Perspectives on July 20, 2012. Environmental Health Perspectives is a publication of the United States National Institutes of Health’s National Institute of Environmental Health Sciences.

In a meta-analysis, researchers from Harvard School of Public Health (HSPH) and China Medical University in Shenyang [funded by the National Institutes of Health (NIH)] for the first time combined 27 studies and found strong indications that fluoride adversely affects cognitive development in children. 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.

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.

And as the International Business Times noted on the newest Chinese study on fluoride:

Exposure to fluoride may lower children’s intelligence, says a study published in Environmental Health Perspectives, a publication of the National Institute of Environmental Health Sciences. Fluoride is added to 70 percent of U.S. public drinking water supplies.


About 28 percent of the children in the low-fluoride area scored as bright, normal or higher intelligence compared to only 8 percent in the “high” fluoride area of Wamaio.

In the high-fluoride city, 15 percent had scores indicating mental retardation and only 6 percent in the low-fluoride city. The authors of the study eliminated both lead exposure and iodine deficiency as possible causes for the lowered IQs.

Studies Have Repeatedly Linked Fluoride to Reduced IQ and Brain Damage

fuoride-01There 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 is amazing 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 …

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.

Studies have shown that fluoride toxicity can lead to a wide variety of health problems, including:

  • Increased lead absorption
  • Disrupts synthesis of collagen
  • Hyperactivity and/or lethargy
  • Muscle disorders
  • Thyroid disease
  • Arthritis
  • Dementia
  • 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.

Indeed, the following video interviewing National Research Council scientists, a Nobel laureate in medicine, a professor of dentistry and other professionals summarizes the evidence fairly succinctly … and makes the case that our understanding of the damage fluoride can cause to our brains is like our growing understanding in the 1970s of the dangers of lead:

(We started the video at 18 minutes in; but the whole video is worth watching.)

Numerous other government reports have shown fluoride’s adverse impacts on intelligence:

[A] 2006 National Academy of Science [report] reviews the scientific studies which have been performed on fluoride, and concludes:

It is apparent that fluorides have the ability to interfere with the functions of the brain and the body by direct and indirect means. (bottom of page 222).

The NAS report also notes that fluoride may actually impair intelligence, and that more testing should be done in this regard.

Indeed, studies from around the world continue to find that exposure to sodium fluoride – especially in the very young – lowers IQ. See this and this. The same is true for rats exposed to fluoride. See this and this. And see the studies listed here.

Dr. Vyvyan Howard – a PhD fetal pathologist, who is a professor of developmental toxico-pathology at the University of Liverpool and University of Ulster, president of the International Society of Doctors for the Environment and former president of the Royal Microscopical Society and the International Society for Stereology, and general editor of the Journal of Microscopy – said in a 2008 Canadian television interview (short, worthwhile video at the link) that studies done in several countries show that children’s IQ are likely to be lower in high natural water fluoride areas.

He said that these studies are plausible because fluoride is known to affect the thyroid hormone which affects intelligence and fluoride is also a known neurotoxicant. Such studies have not been conducted in countries that artificially fluoridate the water such as the US, UK and Canada, but should be, he said.


One scientist – Jennifer Luke – alleged in a 2001 scientific article that fluoride accumulates in the brain (specifically, in the structure of the pineal gland) more than it accumulates in our bones. In other words, she implies that fluoride may accumulate more in the brain than in the teeth, doing more harm than good (here’s Luke’s 1997 PhD dissertation on the topic.)

The 2006 National Academy of Sciences report corroborates some of Luke’s allegations:

As with other calcifying tissues, the pineal glands can accumulate fluoride (Luke 1997, 2001). Fluoride has been shown to be present in the pineal glands of older people (14-875 mg of fluoride per kg of gland in persons aged 72-100 years), with the fluoride concentrations being positively related to the calcium concentrations in the pineal gland, but not to the bone fluoride, suggesting that pineal fluoride is not necessarily a function of cumulative fluoride exposure of the individual (Luke 1997, 2001). Fluoride has not been measured in the pineal glands of children or young adults, nor has there been any investigation of the relationship between pineal fluoride concentrations and either recent or cumulative fluoride intakes.

Donald Miller – cardiac surgeon and Professor of Surgery at the University of Washington – alleges:

Fluoride … inhibits the enzyme acetylcholinesterase in the brain, which is involved in transmitting signals along nerve cells.


Fluoride also damages the brain, both directly and indirectly. Rats given fluoridated water at a dose of 4 ppm develop symptoms resembling attention deficit-hyperactivity disorder. High concentrations of fluoride accumulate in the pineal gland, which produces serotonin and melatonin.


People with Alzheimer’s disease have high levels of aluminum in their brains. Fluoride combines with aluminum in drinking water and takes it through the blood-brain barrier into the brain. Dr. Russell Blaylock, MD, a neurosurgeon, spells out in chilling detail the danger fluoride poses to one’s brain and health in general in his book Health and Nutrition Secrets that can Save Your Life (2002).

Time Magazine notes:

What has also changed is how much toxicologists know about the harmful effects of fluoride compounds. Ingested in high doses, fluoride is indisputably toxic; it was once commonly used in rat poison. Hydrogen fluoride is regulated as a hazardous pollutant in emissions from chemical plants and has been linked to respiratory illness. Even in toothpaste, sodium fluoride is a health concern. In 1997 the Food and Drug Administration toughened the warning on every tube to read, “If more than used for brushing is accidentally swallowed, get medical help or contact a poison-control center right away.”

ABC News from Raleigh-Durham reports:

Study after study dating back to the 80s from respected academic and scientific institutions that connect fluoride to health dangers. Some of the studies were funded by the government. They  suggest fluoride can be linked to brain, blood and bone deficiencies in humans.


“EPA’s drinking water standards are supposed to protect all persons against anticipated adverse health effects of the contaminant in question,” explained Kathleen Thiessen – one of the scientists who worked on the 400-page study. “And we concluded after three years worth of work that the drinking water standard for fluoride was not protected and cannot be assumed to be safe for humans.”

Thiessen  said the EPA was warned about potential fluoride health dangers by one of its own chemists more than a decade ago. Dr. William Hirzy testified before a Senate subcommittee in 2000.  He was representing the views of EPA scientists and staff who analyze hazards in the environment.

“In 1997, we voted to oppose fluoridation, and our opposition has grown stronger as more adverse data on the practice has come in,” said Hirzy.

“The CDC and others say whatever beneficial effect there is from fluoride is from topical use. It’s not from swallowing it. It never has been from swallowing it,” said Thiessen.

The I-Team discovered most western countries do not fluoridate their water. Dental records kept by the World Health Organization show tooth decay in those countries has declined at the same rate as here in the United States – where we do fluoridate our water.

Indeed, an overwhelming number of scientific studies conclude that cavity levels are falling worldwide … even in countries which don’t fluoridate water.  Specifically, the scientific literature shows that – when fluoridation of water supplies is stopped – cavities do not increase (but may in some cases actually decrease).  See this, this, this, this, this and this.

World Health Organization Data (2004) – 
Tooth Decay Trends (12 year olds) in Fluoridated vs. Unfluoridated Countries:


No wonder more and more countries are stopping fluoridation.

In fact, many prominent leaders of the pro-water fluoridation movement have recently admitted publicly that they were wrong. That includes:

  • John Colquhoun, DDS, Principal Dental Officer for Auckland, New Zealand and chair of that country’s Fluoridation Promotion Committee, reviewed New Zealand’s dental statistics in an effort to convince skeptics that fluoridation was beneficial and found that tooth decay rates were the same in fluoridated and nonfluoridated places, which prompted him to re-examine the classic fluoridation studies. He withdrew his support for it in “Why I Changed my Mind About Water Fluoridation” (Perspectives in Biology and Medicine 1997;41:29—44).
  • Richard G. Foulkes, MD, a health care administrator and former assistant professor in the Department of Health Care and Epidemiology at the University of British Columbia also switched from pro to anti-water fluoridation after studying the issue.
  • And Dr. Hardy Limeback PhD, DDS – one of the 12 scientists who served on the 2006 National Academy of Sciences review of fluoride, and Head of Preventive Dentistry at University of Toronto – wrote “Why I am Now Officially Opposed to Adding Fluoride to Drinking Water
  • Dr. Bill Osmunson DDS – “I promoted fluoridation for 25 years,” Dr. Osmunson admits. But then his patients began questioning it and urging him to review the science once again.

    “One of the earlier gentlemen that worked with me… said, “Bill, what about the freedom of allowing people to choose fluoride or not?” I remember my mouth opening up to respond and nothing came out, because I’m very much in favor of freedom. I want people to have the freedom to choose the chemicals, the drugs, whatever they’re doing. Fluoridation removes that freedom.
    … I was certain fluoride was beneficial. I could see it in my patients’ teeth. I was just absolutely certain that it was. When you have a tooth that’s really hard and shiny and looking good, and no decay, that’s the one that’s had fluoride, right?
    Well, I found out I was wrong. I thought I was seeing the effects of fluoride when it really wasn’t…Based on the science, people who have a higher socioeconomic bracket, people who are eating better, they have better teeth. I was looking at it and guessing, “well, this person is benefiting from fluoride” when they really weren’t.”
    “They tell me not to swallow a quarter milligram of fluoride in my toothpaste, but they are forcing me to swallow a quarter milligram in just one glass of water. … It’s unbelievable. We know that we’re getting some neurologic damage at very low levels. However, the latest research is even worse than that. We’re finding an 8-point IQ drop when the serum blood level of fluoride goes from 0.04 to 0.08.
    … The American Dental Association recommends that a woman have about 3 mg per day of fluoride as optimal and men about 4 mg per day as optimal. That is the same amount that causes between a 0.8 and a 0.12 level of fluoride in the blood. The same level showing an 8-point IQ drop!”

What Does a 7-8 point IQ Drop Mean?

Let me first point out that these statistics are based on normal levels found in drinking water. Unfortunately, we get ample fluoride naturally, but we have been adding it to our water and toothpaste; it’s in the pesticides and fumigants of the food we eat (unless you’re eating organic), the teflon pans we cook with, the medicines, etc. Did you know the safe amount of toothpaste based on fluoride levels is a ‘pea size’ amount. Not an adult sized pea, but a baby pea – half the size of the pea you might be thinking about. So, basically, with these fluoride levels added to the amounts we get from drinking tap water, our actual levels may be dropping our IQ in excess of 10 IQ points!

While IQ level doesn’t give the full story behind someone’s income level, based on studies there is certainly some correlation. Based on the numbers below (Source), a 7-8 point drop in IQ points could mean a significant drop in earnings:

  • Three figure income (i.e. homeless):  Average IQ 84
  • Four figure income (i.e. part-time minimum wage worker): Average IQ 92
  • Five figure income (i.e. middle class): Average IQ 100
  • Six figure income (i.e. potential self-made millionaire): Average IQ 108
  • Seven figure income (i.e. potential self-made decamillionaire): Average IQ 116
  • Eight figure income (i.e. potential self-made centimillionaire): Average IQ 124
  • Nine figure income (i.e. potential self-made billionaire): Average IQ 132
  • Ten figure income (i.e. potential self-made decabillionaire): Average IQ 140

Another study confirms these numbers are probably fair, as this study estimates a 2.5% raise in income with a 1 point raise in IQ. Thus, a 10 percent IQ drop could mean a 25% decline in pay.

Fluoride: A Neurotoxin That Damages Your Pineal Gland

If you’ve never heard of the pineal gland, know it’s got a pretty important job. Located in the center of the brain, it’s responsible for melatonin synthesis (which plays a role in maintaining normal rhythms and sleep cycles), and also helps convert signals between our nervous and endocrine systems. Something about melatonin: it’s thought to act as a neuro-protector that could play a role in the aging process and Alzheimer’s, so when it’s messed up by things like fluoride, you can guess what happens. [1] Unfortunately, the pineal gland can develop problems because it can also absorb a lot of fluoride—even more than our bones.

Our bones are exposed to toxic fluoride much more than we might think. The World Health Organization (WHO) suggests: ”Fluoride levels above 1.5 mg per liter cause pitting of tooth enamel and deposits in bones.” [2] And because so much of the water supply in the U.S. is still fluoridated, we’re exposed to levels in the 2 to 5 mg range. This doesn’t even account for the fluoride in dental products.

Back to the pineal gland… Fluoride can accumulate and calcify on the gland, blocking its effectiveness, and these deposits can get worse as we age. [3] A blocked pineal gland could lead to things like trouble sleeping or weight gain. One study even suggests toxic calcification could lead to early onset of puberty in girls. [4]

How to Detoxify the Pineal Gland

If you want to detox and decalcify your pineal gland from fluoride, there are some easy things you can do! First, stop drinking fluoridated water; this means you should probably steer clear of tap water, choosing alkaline or distilled water instead. Another thing you could do is try fluoride-free dental products. Iodine may be another helpful tool to use for detoxifying your pineal gland from excessive fluoride.

Damage to the pineal gland barely scratches the surface when you really get into the dangers of fluoride. I recommend you check out the documentary, Fluoride: Poison on Tap. It explains the magnitude of the fluoride situation and I was even fortunate enough to be a part of it.

So, now that you know a little bit about how fluoride can damage pineal gland health and significantly lower your IQ level, what will you do to avoid it?

Resources: Mercola.com, GlobalHealingCenter.com, HuffingtonPost.com

Recommended Books:


You’re about to discover the shocking truth about how fluoride ended up in your drinking water and how it is really affecting today’s population. Many people aren’t even aware that large amounts of fluoride are being added to the vast majority of the public water supply, and many of those who do know are terribly misinformed about why it’s there and the true effect that it has on our bodies.

When you look at the primary people who were initially involved in mandating water fluoridation, it starts to become quite clear that there is much more to it than trying to strengthen children’s teeth. This book goes into detail about how fluoride ended up in our water, who was involved, the terrifying potential health risks of consuming fluoride in your water, and what you can do to avoid it. Many people have suffered and even died because of fluoride consumption, and my hope is that this book will help the rest of the world wake up to the truth before it’s too late.


  • In a devastating exposé in the tradition of Silent Spring and Fast Food Nation, investigative journalist Randall Fitzgerald warns how thousands of man-made chemicals in our food, water, medicine, and environment are making humans the most polluted species on the planet. A century ago in 1906, when Congress enacted the Pure Food and Drug Act, Americans were promised “better living through chemistry.” Fitzgerald provides overwhelming evidence to shatter this myth, and many others perpetrated by the chemical, pharmaceutical, and processed foods industries. In the face of this national health crisis, Fitzgerald also presents informed and practical suggestions for what we can do to turn the tide and live healthier lives.Consider this:
  • The average American carries a ‘body burden’ of 700 synthetic chemicals
  • Chemicals in tap water can cause reproductive abnormalities and hermaphroditic birth
  • A 2005 study of lactating women in eighteen U.S. states found perchlorate (a toxic component of rocket fuel) in practically every mother’s breast milk


The water you are drinking may be hazardous to your health! Water is the key to all body functions: Digestion; Assimilation; Muscles; Sex; Senses. This book allows you to examine the facts and learn about the best water for your health. Learn what water is safe to drink and use.

“This Bragg book is a shocker and should be required reading in medical schools, health-related fields, high schools and colleges. It should be read by everyone!”
– Chris Linville, M.D.

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