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

Government and Top University Studies: Fluoride Lowers IQ and Causes Other Health Problems

The Harvard School for Public Health reports:

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 [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.

Harvard’s announcement continues:

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.”

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.

And as the International Business Times noted last month 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.

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 gland 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:

who dmft An Overwhelming Number of Scientific Studies Conclude That Cavity Levels are Falling Worldwide ... Even In Countries Which Dont Fluoridate Water

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.
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  • Michael McNew

    Here John Whitehead of the Rutherford Institute warns of the impending techno police state: http://www.youtube.com/watch?v=8muZAn7yKMg&feature=youtube_gdata What does this have to do with putting these chemicals in the water? Simple, if a population is dumbed down then it is far easier to control them. Wasn’t it in Brave New World that chemicals were used to make sure each genetic strata was kept under control?

  • Carl Crenshaw

    Going to Harvard lowers your CSQ,common sense quotient,AMDG

    • r0llinlacs

      Did you even go to elementary school?

  • Mike Knox

    Hitler fluoridated the water in the Nazi concentration camps. I seriously doubt that he was concerned about tooth decay.

  • Conspiracy Crap

    You know what else lowers IQ? Conspiracy theories and the fringe right spin machine that creates them:

    Conspiracy theories
    involving fluoridation are common, and include claims that fluoridation
    was motivated by protecting the U.S. atomic bomb program from
    litigation, that (as famously parodied in the film Dr. Strangelove, where a deranged U.S. Army general claimed that it would “sap and impurify all of our precious bodily fluids”) it is part of a Communist or New World Order
    plot to take over the world, that it was pioneered by a German chemical
    company to make people submissive to those in power, that behind the
    scenes it is promoted by the sugary food or phosphate fertilizer or
    aluminum industries, or that it is a smokescreen to cover failure to
    provide dental care to the poor.[28] One such theory is that fluoridation was a public-relations ruse sponsored by fluoride polluters such as the aluminum maker Alcoa and the Manhattan Project, with conspirators that included industrialist Andrew Mellon and the Mellon Institute’s researcher Gerald J. Cox, the Kettering Laboratory of the University of Cincinnati, the Federal Security Agency’s administrator Oscar R. Ewing, and public-relations strategist Edward Bernays.[96] Specific antifluoridation arguments change to match the spirit of the time.[97]


    I have to agree with Yobol and Ronz. Many of the studies included in
    Choi’s meta-analysis (Table 1) reported fluoride levels of 0.5-1.0 ppm
    (mg/L) in their “reference” populations—the same level of fluoride
    recommended by WHO guidelines for artificially fluoridated water. The
    “high fluoride” populations typically reported drinking water fluoride
    concentrations significantly higher, most coming in far in excess of WHO
    recommended levels. At best, Choi’s meta lends moderate support to the
    hypothesis that extremely high fluoride levels may have neurotoxic
    effects. It says nothing about the effects of artificial water
    fluoridation to recommended levels; as such, it is potentially a
    worthwhile source for our article on fluoride toxicity, but isn’t really relevant to this article. TenOfAllTrades(talk) 00:37, 24 July 2013 (UTC)

    • marxmarv

      I have only one cite with which to answer that: “Dangerous Machinery: Conspiracy Theory as a Transpersonal Strategy of Exclusion” http://onlinelibrary.wiley.com/doi/10.1525/si.2007.30.2.127/abstract

    • nancy weaver

      You could be shown facts over and over again, but you are one of the people that can’t or won’t see the truth of what is happening in America. I pray you wake up before it’s too late.

      • Frank Durkan

        What you are describing is known as “Cognitive dissonance” and you’re right, this man has a huge case of it. Unfortunately, as a result, I think your prayer has little chance of being answered …

      • RealityCheck131

        You could be shown facts over and over again, but you are one of the people that can’t or won’t see that the garbage you agree with is unscientific nonsense. I pray you wake up before it’s too late.

    • Don Mega

      u’re the one bringing conspiracies into it. this fluoride in drinking water is nothing but a financial choice. it’s a toxic byproduct which these companies want to get rid of. they just thought let’s make it appear something beneficial and we can sell it to people instead of paying for it’s destruction. it’s typical greed. leave conspiracies out of it fool. simply because u see some conspiracy theorists supporting all these ideas about fluoride doesn’t mean u have to choose the opposing view. that’s just classic divide and conquer u’re falling for. opt out of it and choose ur own path. then u’ll end up blaming the right people behind it, rather than some boogey men.

    • G Fresh

      Conspiracy Crap wrote:”At best, Choi’s meta lends moderate support to the hypothesis that extremely high fluoride levels may have neurotoxic
      effects. ”
      Extremely high fluoride levels will KILL a human. Do you not know that?

    • G Fresh

      The kind of fluoride that was originally found to be good for teeth was a naturally occurring calcium fluoride. Calcium is used to treat fluoride poisoning. Fluoride with calcium is far less toxic. What’s been used largely was sodium fluoride, which I’ve read may be up to 80 times more toxic than calcium fluoride.
      Now most of the stuff used in the U.S. is untested and seems to be connected with a higher uptake of lead in children.
      Here’s some info from a University of Dartmouth study:
      “Untested Type of Fluoride Used in the Overwhelming Majority of U.S. Water Supplies”


    • b berker

      quoting wiki? LMAO

  • kjuhler .

    9 out of 10 Antidepressants have, you guessed it, Fluoride.

  • michiganpatriot

    Key words many here seem to have missed….

    strong indication
    more research
    may not
    seems to
    may seem
    can be
    may actually
    more testing
    are likely
    may lower
    possible causes
    she implies
    ingested in high doses

    All words taken from the article. Not too awfully positive now is it? Nothing I love more than reading words such as these and then seeing how panic stricken some become on something that is no where near proven…..panic based on assumptions.

    And the best absolute part of the article?

    “Such studies have not been conducted in countries that artificially fluoridate the water such as US, UK, and Canada but should be, he said.”

    lol! Watch out for the boogeyman!

    • Don Mega

      u’re funny, because in scientific method there is very little that can be absolutely proven. most of the best studies out there use these very same words. that’s because scientific mind always leaves room for improvement. not everything here is associated with those words so some things are pretty much guaranteed even. brushing with fluoride makes little sense but to drink fluoride is just stupid, it won’t even touch ur teeth to make any difference. it barely touches some of the front teeth, that’s not effective in any way so it’s pretty stupid idea in the first place. and in case u didn’t know ingesting fluoride provides zero benefits, only harm, so it really comes down to the teeth. and i’ve seen pretty damned nice teeth for people who used fluoride free toothpaste, so it’s not a must at all.

  • KrustyLovesYou

    So, Fluoride generates liberals….

  • RayEstonSmithJr

    is referring (obliquely and misleadingly) to naturally occurring high
    fluoride levels from ground water – levels higher than municipal
    fluoridated water. Any substance (including pure water) is toxic in
    high enough doses.

    “most of the epidemiological information available on associations with
    children’s neurodevelopment is from China, where fluoride generally
    occurs in drinking water as a natural contaminant, and the concentration
    depends on local geological conditions. In many rural communities in
    China, populations with high exposure to fluoride in local
    drinking-water sources may reside in close proximity to populations
    without high exposure NRC 2006).

    Opportunities for epidemiological studies depend on the existence of comparable
    population groups exposed to different levels of fluoride from drinking
    water. Such circumstances are difficult to find in many industrialized
    countries, because fluoride concentrations in community water are
    usually no higher than 1 mg/L, even when fluoride is added to water
    supplies as a public health measure to reduce tooth decay. Multiple
    epidemiological studies of developmental fluoride neurotoxicity were
    conducted in China because of the high fluoride concentrations that are
    substantially above 1 mg/L in well water in many rural communities,”

    • j from columbus

      The naturally occurring fluoride in water isn’t any comparison to the toxic waste bought from china and other manufacturing industries that contain over 300 other toxic chemicals that are by volume dumped in our clean drinking water.I’d don’t want to get into the forced medication aspect of mass fluoridation nor the combination of lead and mercury compounds that are also added with the water treatment process. It hasn’t been proven that fluoride will prevent tooth decay but it is a good anti-bacteria agent because of it’s toxicity. The dosages that are given in the water are not measured weather you are an infant or elderly so toxicity levels can not be accurately measured. The fluoride is a toxic poison, that has been in rat poison. The combination of fluoride in your drinking water, toothpaste, food, mouthwash and even SSRI’s such as ant-depressants could lead for severe neurological dysfunction and reduced I.Q. levels of the people that ingest over-intoxicating levels. After detoxification I dropped using fluoride products and filtered my well water and now I think clearly, have less headaches, test scores went up one grade level, and my overall heath is improving substantially.

  • hostage707

    I always love how when they get a bad indication from a series of tests and experiments that go against policy, they always say “we need to run more tests”. How freaking stupid are scientists. Its very simple. There is no legitimate use for a poison like fluoride in something humans consume. It is bad for you. No one is making fluoride vitamins ! It is that simple !

  • billstampede

    FLOURIDE attacks the pineal gland in the brain. dumbing down America is the agenda believe that its a fact. our vaccines have thymerisol (a derivative of mercury) and aluminum. flu shots don’t prevent flu but they push it everywhere,foods have gmo’s, aspartame, silicone in nuggets growth hormones in cows and chickens i can go on and on. its unbelievable how cancer rates have gone up by thousands %%% autism was 1 out of 25000 20 years ago now its 1 i around 60 really. its a fact we are being targeted the sooner we face that, the quicker we can do something about it. fact:::: fluoride is toxic. WAKE UP AMERICA

  • sideswiped

    One week after this article came out I was poisoned by 4 tablets of a Fluoride antibiotic Levaquin. First my tendons nearly ruptured, then my pineal gland went haywire. There is no known cure.

  • BriPalm

    This is exactly why I invested in a LINX
    drinking water system years ago! Too many scary facts about drinking water
    contamination. I don’t trust fluoride in my water. A couple of years ago, buying that system was the best decision I had ever made. Not only does it filter fluoride and tons of other tap water contaminants, but it has virtually NO water waste so I think that is really important too. They can test and test and test my water but the risks just aren’t worth it to my family (not just with fluoride but the many contaminants out there). I highly recommend LINX filters to anyone in my situation. Their site has tons of info (www.linxwater.com) and can really help anyone out who wants to filter their water from fluoride and other contaminants.

  • Hi! Thank you for your article. It has been truly amazing. I think these researchers are very interesting, especially the fact that the adversely affect cognitive development in children and teenagers and the point that the investigators speculate that dangerous toxics effects on brain development may have happened earlier, and that the brain may not be fully capable of compensating for the toxicity.
    I would like share with you another link (is in Spanish) very interesting about this topic. I hope it will be usefull for you. http://www.dentistaenvalencia.net/que-son-las-infecciones-bucales-y-como-tratarlas/