7 ms·

Association Between Maternal Fluoride Exposure During Pregnancy and IQ Scores

36 points by rgrieselhuber 4y ago

giantg2 4y ago
Interesting. Is it odd that the IQ scores were over 100? For example, population IQ is supposed to be 100. So a score of 105 for boys with a 5 point drop would give us the expected result of average intelligence, right?
- InitialLastName 4y ago
  This could just a) be Flynn effect in action (although I would think that would take longer) [0], or b) there are other factors in the sample group (Canadians) that shift them slightly higher in baseline IQ (nutrition? educational exposure?). [0] https://en.wikipedia.org/wiki/Flynn_effect https://en.wikipedia.org/wiki/Flynn_effect
  - rory 4y ago
    > these children were recruited from 6 of 10 cities included in the original cohort: Vancouver, Montreal, Kingston, Toronto, Hamilton, and Halifax Probably just the difference between this cohort vs. all Canadians (urban and rural).
- weberer 4y ago
  >Between 2008 and 2011, the Maternal-Infant Research on Environmental Chemicals (MIREC) program recruited 2001 pregnant women from 10 cities across Canada. Women who could communicate in English or French, were older than 18 years, and were within the first 14 weeks of pregnancy were recruited from prenatal clinics. Participants were not recruited if there was a known fetal abnormality, if they had any medical complications, or if there was illicit drug use during pregnancy. Additional details are in the cohort profile description. Seems like that would filter out the lower end of the bell curve, especially regarding drug use.
devmor 4y ago
IQ scores? Really? Should we look at the correlation to phrenology reports and the subjects balance of humours as well?
- AbrahamParangi 4y ago
  Are you under the impression that IQ scores don’t measure anything?
  - mjburgess 4y ago
    very low IQ scores correlate with ordinary measures of mental performance. Above 100, they're randomly correlated with generic extrinsic measures of performance, and have little test-retest consistency. You can differ as much in your test-retest score as would be the gap between mental retardation and "normal". Above 100, they're mostly a measure of proficiency at taking written tests. In any case, there is no theory of what IQ measures other than by assertion that it measures "intelligence", so there's nothing actually to be said about it. It's a means of extracting apparent patterns in some test answers; there is no scientific theory of what those patterns mean.
    - AbrahamParangi 4y ago
      Extracting apparent patterns in [test answers] is a cognitively difficult task, and is thus a reasonable metric of performing cognitively difficult tasks. Given that this is what we are attempting to measure, it seems completely fine. Pointing out flaws in the test (lack of generality, non-deterministic behavior) is not actually a counter-argument so long as the test correlates with at least some outcomes that we care about. And it does! And this is very reproducible!
      - mjburgess 4y ago
        No no, i mean the psychometrist is the person superstitiously using the fact that answers to their choice of questions correlate, as some measure of something. The claim that IQ tests are "cognitively difficult" is either trivial or unevidenced. Its trivial in the sense that most tasks are "cognitively difficult", that doesnt make them valid measures of cognitive difficulty. It is unevidenced in the sense that there is no theory of what "cognitive difficulty" means that can be tested. My apologies, but IQ tests really are actually pseudoscience. They're a product of a discipline which superstitiously uses GUI-statistical tooling without understanding anything abotu the scientific method, nor the statistical metrics that these tools report. An animal, and its intelligence, is a complex chaotic system whose "cognitition" or "intelligence" is by no means measured by an IQ test. And such a claim is prima fascie ridiculous from any actual biological (ie., theory-building, scientific) study of intelligence.
heliodor 4y ago
The wording in the summary could have been done better. Read casually, it comes across as suggesting causation instead of correlation: Findings -- In this prospective birth cohort study, fluoride exposure during pregnancy was associated with lower IQ scores in children aged 3 to 4 years. Meaning -- Fluoride exposure during pregnancy may be associated with adverse effects on child intellectual development, indicating the possible need to reduce fluoride intake during pregnancy.
- PuppyTailWags 4y ago
  *only in boys, according to the study this reads like cherry-picking to me.
streptomycin 4y ago
https://www.sciencemediacentre.org/expert-reaction-to-study-looking-at-maternal-exposure-to-fluoride-and-iq-in-children/ https://www.sciencemediacentre.org/expert-reaction-to-study-... are some skeptical comments from other scientists in the field.
- Wadajot 4y ago
- saalweachter 4y ago
  The chief complaint seems to be that they only found statistical significance on one measure for one subpopulation (boys), and other measures were not significant (and while the correlation for girls was not statistically significant, it was leaning the opposite direction!). Sure, maybe there's a correlation purely centered around boy's non-verbal IQ scores, but it smells a lot like a "if you look for enough correlations you'll eventually find one".
hirundo 4y ago
If flouride indeed both strengthens teeth and bones and lowers IQ, it becomes even more challenging to pick an optimum level. I think that the more complex a question is, the more important it is for the answers to be decentralized so that we can experiment with many of them. If fluoride does have significant negative as well as positive effects, that's an argument toward removing it from water supplies and making it a choice. Reasonable people could decide that they prefer weaker bones than minds, or visa versa.
- thebigspacefuck 4y ago
  The “Nursery” water (sold at Walmart, Walgreens, etc) for mixing with formula has fluoride added to it. It’s nonsensical. Example: https://i5.walmartimages.com/asr/d45b6df1-099b-4568-b2a9-5ddacc30740a_1.f4728a42877aeb18ca73056cc4a891a4.jpeg https://i5.walmartimages.com/asr/d45b6df1-099b-4568-b2a9-5dd... What purpose does it serve? We can all get behind breastfeeding raising IQ (https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(15)01024-7.pdf https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736...) but maybe it’s the fluoride in the formula lowering IQ.
  - deleted 4y ago
    [deleted]
  - PlsDntBan 4y ago
    So, medicated water for children? 10 years ago I chose to have my kids in a community that does not fluoridate the water because there has LONG been an association with IQ and ingesting fluoride. But, MOST insanely, fluoride is by all account a medicine, we are one of the ONLY countries in the world that medicates our water supply. Just think about it, why do we medicate our ENTIRE water supply? There is something terrible behind the fluoridation of the American water supply, I have no idea what but I do know that as a scientist what we are doing makes no sense and is VASTLY more harmful then beneficial.
  - wil421 4y ago
    Those are supposed to have lower fluorine than tap water. According to the CDC, babies who only drink formula with tap water can develop dental fluorosis, faint white lines on the teeth.[1]. It’s not always possible to breastfeed. [1] https://www.cdc.gov/fluoridation/faqs/infant-formula.html https://www.cdc.gov/fluoridation/faqs/infant-formula.html
mminer237 4y ago
Previous discussions: - https://news.ycombinator.com/item?id=20742682 https://news.ycombinator.com/item?id=20742682 - https://news.ycombinator.com/item?id=20739540 https://news.ycombinator.com/item?id=20739540
civilized 4y ago
This study has a lot of the hallmarks of pure noise that won't replicate. - Small sample size (601 kids) - Effect has opposite sign in girls and boys - Negative association in boys was barely statistically significant - Positive association in girls barely missed statistical significance Not to mention we're testing IQ in 4-year-olds.
bell-cot 4y ago
Insert the obligatory USAF General Jack T. Ripper quote, about the Soviets fluoridating our water supplies, to pollute the "precious bodily fluids" of American men. [ https://en.wikipedia.org/wiki/Dr._Strangelove#Plot https://en.wikipedia.org/wiki/Dr._Strangelove#Plot ] (No, I am not a public health professional, to know if their study's design or other research would rule out paternal exposure to fluorine as a cause. However, I have a very strong impression that both public opinion and most medical professionals are strongly sexist about problems with pregnancy and young children - "anything wrong is the mother's fault".)

36 points by rgrieselhuber 4y ago

Interesting. Is it odd that the IQ scores were over 100? For example, population IQ is supposed to be 100. So a score of 105 for boys with a 5 point drop would give us the expected result of average intelligence, right?

InitialLastName 4y ago
This could just a) be Flynn effect in action (although I would think that would take longer) [0], or b) there are other factors in the sample group (Canadians) that shift them slightly higher in baseline IQ (nutrition? educational exposure?). [0] https://en.wikipedia.org/wiki/Flynn_effect https://en.wikipedia.org/wiki/Flynn_effect
- rory 4y ago
  > these children were recruited from 6 of 10 cities included in the original cohort: Vancouver, Montreal, Kingston, Toronto, Hamilton, and Halifax Probably just the difference between this cohort vs. all Canadians (urban and rural).
weberer 4y ago
>Between 2008 and 2011, the Maternal-Infant Research on Environmental Chemicals (MIREC) program recruited 2001 pregnant women from 10 cities across Canada. Women who could communicate in English or French, were older than 18 years, and were within the first 14 weeks of pregnancy were recruited from prenatal clinics. Participants were not recruited if there was a known fetal abnormality, if they had any medical complications, or if there was illicit drug use during pregnancy. Additional details are in the cohort profile description. Seems like that would filter out the lower end of the bell curve, especially regarding drug use.

devmor 4y ago

IQ scores? Really? Should we look at the correlation to phrenology reports and the subjects balance of humours as well?

AbrahamParangi 4y ago
Are you under the impression that IQ scores don’t measure anything?
- mjburgess 4y ago
  very low IQ scores correlate with ordinary measures of mental performance. Above 100, they're randomly correlated with generic extrinsic measures of performance, and have little test-retest consistency. You can differ as much in your test-retest score as would be the gap between mental retardation and "normal". Above 100, they're mostly a measure of proficiency at taking written tests. In any case, there is no theory of what IQ measures other than by assertion that it measures "intelligence", so there's nothing actually to be said about it. It's a means of extracting apparent patterns in some test answers; there is no scientific theory of what those patterns mean.
  - AbrahamParangi 4y ago
    Extracting apparent patterns in [test answers] is a cognitively difficult task, and is thus a reasonable metric of performing cognitively difficult tasks. Given that this is what we are attempting to measure, it seems completely fine. Pointing out flaws in the test (lack of generality, non-deterministic behavior) is not actually a counter-argument so long as the test correlates with at least some outcomes that we care about. And it does! And this is very reproducible!
    - mjburgess 4y ago
      No no, i mean the psychometrist is the person superstitiously using the fact that answers to their choice of questions correlate, as some measure of something. The claim that IQ tests are "cognitively difficult" is either trivial or unevidenced. Its trivial in the sense that most tasks are "cognitively difficult", that doesnt make them valid measures of cognitive difficulty. It is unevidenced in the sense that there is no theory of what "cognitive difficulty" means that can be tested. My apologies, but IQ tests really are actually pseudoscience. They're a product of a discipline which superstitiously uses GUI-statistical tooling without understanding anything abotu the scientific method, nor the statistical metrics that these tools report. An animal, and its intelligence, is a complex chaotic system whose "cognitition" or "intelligence" is by no means measured by an IQ test. And such a claim is prima fascie ridiculous from any actual biological (ie., theory-building, scientific) study of intelligence.

heliodor 4y ago

The wording in the summary could have been done better. Read casually, it comes across as suggesting causation instead of correlation: Findings -- In this prospective birth cohort study, fluoride exposure during pregnancy was associated with lower IQ scores in children aged 3 to 4 years. Meaning -- Fluoride exposure during pregnancy may be associated with adverse effects on child intellectual development, indicating the possible need to reduce fluoride intake during pregnancy.

PuppyTailWags 4y ago
*only in boys, according to the study this reads like cherry-picking to me.

streptomycin 4y ago

https://www.sciencemediacentre.org/expert-reaction-to-study-looking-at-maternal-exposure-to-fluoride-and-iq-in-children/ https://www.sciencemediacentre.org/expert-reaction-to-study-... are some skeptical comments from other scientists in the field.

Wadajot 4y ago
saalweachter 4y ago
The chief complaint seems to be that they only found statistical significance on one measure for one subpopulation (boys), and other measures were not significant (and while the correlation for girls was not statistically significant, it was leaning the opposite direction!). Sure, maybe there's a correlation purely centered around boy's non-verbal IQ scores, but it smells a lot like a "if you look for enough correlations you'll eventually find one".

hirundo 4y ago

If flouride indeed both strengthens teeth and bones and lowers IQ, it becomes even more challenging to pick an optimum level. I think that the more complex a question is, the more important it is for the answers to be decentralized so that we can experiment with many of them. If fluoride does have significant negative as well as positive effects, that's an argument toward removing it from water supplies and making it a choice. Reasonable people could decide that they prefer weaker bones than minds, or visa versa.

thebigspacefuck 4y ago
The “Nursery” water (sold at Walmart, Walgreens, etc) for mixing with formula has fluoride added to it. It’s nonsensical. Example: https://i5.walmartimages.com/asr/d45b6df1-099b-4568-b2a9-5ddacc30740a_1.f4728a42877aeb18ca73056cc4a891a4.jpeg https://i5.walmartimages.com/asr/d45b6df1-099b-4568-b2a9-5dd... What purpose does it serve? We can all get behind breastfeeding raising IQ (https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(15)01024-7.pdf https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736...) but maybe it’s the fluoride in the formula lowering IQ.
- deleted 4y ago
  [deleted]
- PlsDntBan 4y ago
  So, medicated water for children? 10 years ago I chose to have my kids in a community that does not fluoridate the water because there has LONG been an association with IQ and ingesting fluoride. But, MOST insanely, fluoride is by all account a medicine, we are one of the ONLY countries in the world that medicates our water supply. Just think about it, why do we medicate our ENTIRE water supply? There is something terrible behind the fluoridation of the American water supply, I have no idea what but I do know that as a scientist what we are doing makes no sense and is VASTLY more harmful then beneficial.
- wil421 4y ago
  Those are supposed to have lower fluorine than tap water. According to the CDC, babies who only drink formula with tap water can develop dental fluorosis, faint white lines on the teeth.[1]. It’s not always possible to breastfeed. [1] https://www.cdc.gov/fluoridation/faqs/infant-formula.html https://www.cdc.gov/fluoridation/faqs/infant-formula.html

mminer237 4y ago

Previous discussions: - https://news.ycombinator.com/item?id=20742682 https://news.ycombinator.com/item?id=20742682 - https://news.ycombinator.com/item?id=20739540 https://news.ycombinator.com/item?id=20739540

civilized 4y ago

This study has a lot of the hallmarks of pure noise that won't replicate. - Small sample size (601 kids) - Effect has opposite sign in girls and boys - Negative association in boys was barely statistically significant - Positive association in girls barely missed statistical significance Not to mention we're testing IQ in 4-year-olds.

bell-cot 4y ago

Insert the obligatory USAF General Jack T. Ripper quote, about the Soviets fluoridating our water supplies, to pollute the "precious bodily fluids" of American men. [ https://en.wikipedia.org/wiki/Dr._Strangelove#Plot https://en.wikipedia.org/wiki/Dr._Strangelove#Plot ] (No, I am not a public health professional, to know if their study's design or other research would rule out paternal exposure to fluorine as a cause. However, I have a very strong impression that both public opinion and most medical professionals are strongly sexist about problems with pregnancy and young children - "anything wrong is the mother's fault".)