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Thread: Drinking fluoridated water during pregnancy may lower IQ in sons, controversial study says

  1. #1

    Drinking fluoridated water during pregnancy may lower IQ in sons, controversial study says

    Drinking fluoridated water during pregnancy may lower IQ in sons, controversial study says
    By Michael PriceAug. 19, 2019 , 11:20 AM

    First piloted as an experiment to reduce dental cavities in Grand Rapids, Michigan, in 1945, fluoridated drinking water has since been hailed by the U.S. Centers for Disease Control and Prevention in Atlanta as “one of public health’s greatest success stories.” Today, about two-thirds of people in the United States receive fluoridated tap water, as do many people in Australia, Brazil, Canada, New Zealand, Spain, and the United Kingdom. Now, a controversial new study links fluoridation to lower IQ in young children, especially boys whose mothers drank fluoridated water while pregnant.

    Longtime fluoridation critics are lauding the study, but other researchers say it suffers from numerous flaws that undercut its credibility. Either way, “It’s a potential bombshell,” says Philippe Grandjean, an environmental health researcher at Harvard University who wasn’t involved in the work.

    Fluoride is well-known for protecting teeth against cavities by strengthening tooth enamel. It’s found naturally in low concentrations in both freshwater and seawater, as well as in plant material, especially tea leaves. Throughout the 1940s and ’50s, public health researchers and government officials in cities around the world experimentally added fluoride to public drinking water; they found it reduced the prevalence of cavities by about 60%. Today, fluoridated water flows through the taps of about 5% of the world’s population, including 66% of Americans and 38% of Canadians.

    Yet skepticism has dogged the practice for as long as it has existed. Some have blamed fluoridated water for a wide range of illnesses including cancer, but most criticism has been dismissed as pseudoscience. Over the years, though, a small number of scientists have published meta-analyses casting doubt on the efficacy of water fluoridation in preventing cavities. More recently, scientists have published small-scale studies that appear to link prenatal fluoride exposure to lower IQ, although dental research groups were quick to challenge them.

    A study out today in JAMA Pediatrics offers perhaps the highest profile critique to date. Psychologists and public health researchers looked at data from Canada’s federally funded Maternal-Infant Research on Environmental Chemicals program, a long-term study of pregnant women and their children in six Canadian cities that started to collect data in 2008 on everything from diet to education levels to traces of lead and arsenic in the urine.

    About 40% of the nearly 600 women lived in cities with fluoridated drinking water; they had an average urinary fluoride level of 0.69 milligrams per liter, compared with 0.4 milligrams for women living in cities without fluoridated water. Three to 4 years after the women gave birth, researchers gave their children an age-appropriate IQ test. After controlling for variables such as parental education level, birth weight, prenatal alcohol consumption, and household income, as well as exposure to environmental toxicants such as lead, mercury, and arsenic, they found that if a mother’s urinary fluoride levels increased by 1 milligram per liter, her son’s (but not her daughter’s) IQ score dropped by about 4.5 points. That effect is on par with the other recent studies looking at childhood IQ and low-level lead exposure.

    Using a secondary method for measuring fluoride intake—mothers’ self-reports of how much tap water and fluoride-rich tea they drank throughout pregnancy—they found a 1-milligram-per-liter increase in fluoride was associated with a 3.7-point IQ score drop in both boys and girls. Self-reporting is a less widely accepted method because it’s considered less reliable and prone to inaccurate recall. The researchers admit they aren’t sure why there’s a sex discrepancy between the two methods, though they say it could arise from the different ways in which boys and girls absorb environmental toxins in utero. For both findings, the authors declined to speculate on the exact mechanism at work.

    If the work holds up—a big “if,” as the paper’s findings are already coming under heavy scrutiny—it could hold serious implications for public policy. According to recommendations from the U.S. Department of Health and Human Services, drinking a liter of fluoridated water should provide about 0.7 milligrams of fluoride. “If you just drink 1 liter [of tap water] and then in addition have a couple mugs of tea, then the fluoride concentration in the tea is enough to get you over the limit proposed,” Grandjean notes.

    The authors are fully aware of the controversial nature of their work, and one of them—Rivka Green, a neuropsychology doctoral candidate at York University in Toronto, Canada—says she hopes the study will jump-start further research. “We tried to be as cautious and careful as possible,” she says. “We’re not coming in saying that fluoride is poison or anything like that. We’re just … letting the data tell the story.”

    Aware that the study’s findings were likely to make waves, JAMA Pediatrics took the unusual step of publishing an editor’s note accompanying the paper. “This decision to publish this article was not easy,” writes the journal’s editor, pediatrician and epidemiologist Dimitri Christakis of Seattle Children’s Hospital in Washington. He adds that the paper was “subjected [to] additional scrutiny for its methods and the presentation of its findings.”

    Despite that, several researchers argue that the paper’s methodological shortcomings undercut its importance. In a statement to the Science Media Centre in London, an independent organization that sources expert opinions on science in the news, psychologist Thom Baguley of Nottingham Trent University in the United Kingdom noted the data “are very noisy,” meaning they contain a lot of other factors that could easily lead to false positives. Psychologist Stuart Ritchie at King’s College London added that the findings are just barely statistically significant, calling them “pretty weak and borderline.” By itself, the study “shouldn’t move the needle much at all on the question of the safety of fluoride,” he wrote.

    Lindsay McLaren, a public health researcher at the University of Calgary in Canada, disagrees. She tells Science that the study appears both credible and methodologically sound—but she agrees it’s too early to change fluoridation practices. “Public policy is ideally informed not by any one study, but by the best available evidence as a whole,” she says. “It will be important to continue to review and appraise new research on fluoride and fluoridation.”
    https://www.sciencemag.org/news/2019...zen.yandex.com
    My website: https://www.theherbsofthefield.com/

    "No one is useless in this world who lightens the burdens of another.” ~ Charles Dickens



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  3. #2
    Hopefully soon all vaccinations can be administered via drinking water. Fluoride has done wonders for teeth! I bet you won't find any decayed teeth in a fetus.

  4. #3
    Using a secondary method for measuring fluoride intake—mothers’ self-reports of how much tap water and fluoride-rich tea they drank throughout pregnancy—they found a 1-milligram-per-liter increase in fluoride was associated with a 3.7-point IQ score drop in both boys and girls.
    Margin of error on an IQ test is +/- five points- your score may actually be five points higher or five points lower than reported results- so the survey was well within that margin.

    If the work holds up—a big “if,” as the paper’s findings are already coming under heavy scrutiny—
    The authors are fully aware of the controversial nature of their work,
    Quote Originally Posted by Swordsmyth View Post
    The quality seems to have dropped significantly since I came here, I guess you get what you pay for.
    "There is always a tweet. That has become accepted fact in the Trump presidency: For every pronouncement the President makes, there is at least one tweet from his past that directly contradicts his current view." -CNN

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  5. #4
    Fluoride levels and osteosarcoma
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3876610/

    CANCER
    https://fluoridealert.org/issues/health/cancer/


    What are the long-term effects of ingesting fluoride on our bones?
    http://fluoridation.com/bones.htm
    My website: https://www.theherbsofthefield.com/

    "No one is useless in this world who lightens the burdens of another.” ~ Charles Dickens

  6. #5
    https://www.webmd.com/oral-health/ne...-teeth-bones#1

    Researchers found that drinking fluoridated tap water slightly improved bone density in women and reduced their risk of hip and spine fractures.

    The study focused on more than 7,000 Midwestern women -- all at least 65 years old -- and found that "community water fluoridation slightly decreased risk of fractures at both hip and spine in older white women," says study author Kathy Phipps, PhD, an epidemiologist, bone and mineral expert, and associate professor at Oregon Health Sciences University. "This is the first comprehensive study of this issue," says Phipps, whose study was published in the British Medical Journal.
    Quote Originally Posted by Swordsmyth View Post
    The quality seems to have dropped significantly since I came here, I guess you get what you pay for.
    "There is always a tweet. That has become accepted fact in the Trump presidency: For every pronouncement the President makes, there is at least one tweet from his past that directly contradicts his current view." -CNN

    I am Zippy and I approve of this post. But you don't have to.

  7. #6
    Yes I heard it is also very good for teeth! I bet you never seen a fetus with bad teeth.

  8. #7
    Quote Originally Posted by Zippyjuan View Post
    Margin of error on an IQ test is +/- five points- your score may actually be five points higher or five points lower than reported results- so the survey was well within that margin.
    If the margin of error is +/- five points, is it possible that fluoride actually raises IQ?

  9. #8
    Quote Originally Posted by Schifference View Post
    If the margin of error is +/- five points, is it possible that fluoride actually raises IQ?
    The difference was insignificant in either direction.
    Quote Originally Posted by Swordsmyth View Post
    The quality seems to have dropped significantly since I came here, I guess you get what you pay for.
    "There is always a tweet. That has become accepted fact in the Trump presidency: For every pronouncement the President makes, there is at least one tweet from his past that directly contradicts his current view." -CNN

    I am Zippy and I approve of this post. But you don't have to.



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  11. #9
    Quote Originally Posted by Zippyjuan View Post
    Margin of error on an IQ test is +/- five points- your score may actually be five points higher or five points lower than reported results- so the survey was well within that margin.
    The nonsense just keeps coming; anything to defend big pharma, right?!?

    Following is the definition of the standard deviation. As you can see the standard deviation becomes less with increasing N (divide by N-1)...
    When you divide the 5 IQ points with the square root of 599 (for nearly 600 women), this becomes 0.2.

    This isn´t the SD of course, which is (mostly) defined by the normal distribution (which would be higher than 0.2), also in the picture below.
    Last edited by Firestarter; 08-20-2019 at 09:23 AM.
    Do NOT ever read my posts.
    Google and Yahoo wouldn’t block them without a very good reason: http://www.ronpaulforums.com/showthr...he-world/page3

  12. #10
    The following literature review by Peckham an Awofeso from 2014 is not so positive about the health effects of fluoride.

    In a meta-analysis of 27 mostly China-based studies on fluoride and neurotoxicity, researchers from Harvard School of Public Health and China Medical University in Shenyang found strong indications that fluoride may adversely affect cognitive development in children [50]. All but one study suggested that high fluoride content in water may negatively affect cognitive development. The average loss in intelligence quotient (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 [50]. While fluoride's effect on IQ in this meta-analysis did not reach statistical significance, the combined effect at population level is remarkable. A particular concern of the NRC committee was the impact of ingested fluoride on the thyroid gland [49]. In a 2005 study, it was found that 47% of children living in a New Delhi neighbourhood with average water fluoride level of 4.37 ppm have evidence of clinical hypothyroidism attributable to fluoride. They found borderline low FT3levels among all children exposed to fluoridated water [51].
    Water Fluoridation: A Critical Review of the Physiological Effects of Ingested Fluoride as a Public Health Intervention” (2014): https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3956646/


    A “scientific” report that was published in September 2017 shows that higher prenatal fluoride exposure was associated with lower scores on IQ tests in children from age 4 to 12.
    In Mexico, where this study was conducted, fluoride isn’t added to water, but to table salt instead.

    A total of 299 mother–child pairs had data on either GCI (at 4 years old) or IQ (at 6 years or older), and 199 mother–child pairs had data on both GCI and IQ.
    At age 4 year, neurocognitive outcomes (GCI) were measured using the McCarthy Scales of Children’s Abilities (MSCA).
    For children 6–12 year old, the Wechsler Abbreviated Scale of Intelligence (WASI) was administered (IQ).
    The children’s IQ wasn’t only compared to the prenatal fluoride exposure, but was also corrected for lead exposure, maternal IQ and the quality of the children’s individual home environments.

    Figure 2, shows the (adjusted) correlation between urinary fluoride level (MUF) and General Cognitive Index (GCI) scores in children at age 4. You can see that averagely the children score lower with higher prenatal fluoride exposure.


    Figure 3, shows the (adjusted) correlation between urinary fluoride level (MUF) and IQ at age 6–12. It looks like only fluoride levels higher than 1 mg/l prenatal are associated with a lower IQ.


    M. Bashash et al “Prenatal Fluoride Exposure and Cognitive Outcomes in Children at 4 and 6–12 Years of Age in Mexico (2017): https://ehp.niehs.nih.gov/ehp655/
    (archived here: http://archive.is/Ue2SU)
    Do NOT ever read my posts.
    Google and Yahoo wouldn’t block them without a very good reason: http://www.ronpaulforums.com/showthr...he-world/page3

  13. #11
    Quote Originally Posted by Firestarter View Post
    The nonsense just keeps coming; anything to defend big pharma, right?!?

    Following is the definition of the standard deviation. As you can see the standard deviation becomes less with increasing N (divide by N-1)...
    When you divide the 5 IQ points with the square root of 599 (for nearly 600 women), this becomes 0.2.

    This isn´t the SD of course, which is (mostly) defined by the normal distribution (which would be higher than 0.2), also in the picture below.
    Standard deviation on IQ tests is 20 which is roughly five points margin of error.
    Quote Originally Posted by Swordsmyth View Post
    The quality seems to have dropped significantly since I came here, I guess you get what you pay for.
    "There is always a tweet. That has become accepted fact in the Trump presidency: For every pronouncement the President makes, there is at least one tweet from his past that directly contradicts his current view." -CNN

    I am Zippy and I approve of this post. But you don't have to.

  14. #12
    Quote Originally Posted by Zippyjuan View Post
    Margin of error on an IQ test is +/- five points- your score may actually be five points higher or five points lower than reported results- so the survey was well within that margin.
    So you first made a ridiculous comment and now continue with another ridiculous comment that contradicts you earlier foolishness...
    Quote Originally Posted by Zippyjuan View Post
    Standard deviation on IQ tests is 20 which is roughly five points margin of error.
    For a large sample, like we have here, the standard deviation is determined by the "normal distribution".
    Not by the "error" in the individual "estimates" of IQ (unless of course there's a systematic error)...
    Quote Originally Posted by Firestarter
    Do NOT ever read my posts.
    Google and Yahoo wouldn’t block them without a very good reason: http://www.ronpaulforums.com/showthr...he-world/page3

  15. #13
    Zip's not a math genius. Lol.



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