My worst string of dental caries happened when I lived in an area without fluoridated water! I wish I had known it wasn't fluoridated so I could have been doing fluoride rinses back then. Expensive and painful personal lesson!
Dear, Dr. Steir & Nina Munoz. Well done. At first I had thought "Who drinks from the tap these days" . But of course the answer is all of those folks who can't afford alternatives. The ones most likely to not get proper dental care.
Google experts strike again! I am grateful for knowledgeable people like you who help to explain results in an understandable and meaningful way instead of fear-mongering. Thank you!
First off, shouldn't the burden of proof for a health intervention be on the pro-intervention side? Are you not arguing that water fluoridation does not need to be studied in high quality expensive trials because the quality of these studies showing damage is questionable? How can you make this argument? It is precisely people like you who are trying to guarantee that no one ever does a high quality study of the issue at hand.
Nonetheless, let's dig into some of your 'refutations'. I selected a few at random and skimmed through the papers.
1. Khan et al (2015)
>>The study's design cannot establish causation<<
As you know, it is not feasible to establish causation within a single study of this scope. The study is not seeking to do so. Your invocation of this fact only serves to misrepresent the actual findings of the study to your audience.
>>the researchers failed to control for essential variables like socioeconomic status, parental education, and other environmental exposures.<<
How so? Because it's not a double blind RCT with careful sample selection? Are you not specifically advocating against carrying out such a trial in a developed country with this article you've written? The authors appear to be doing the best they can with the resources feasibly available to them. The authors selected two sample groups with "similar socio-economic status, standards of living, quality of education, medical facilities, and cultural status". It would have been nice to see this characterized more scientifically, but it's a bold misrepresentation of the study to say "they failed" to control for these things.
>>With only 429 children and measurements taken at a single time point, the study cannot account for historical exposure variations or demonstrate a clear causal relationship.<<
OK. I don't know who you're reading that is citing this paper in this way, but the paper raises valid concerns about the effect of fluorosis on childhood IQ. You did not effectively debunk this citation at all.
3. Yu et al. (2018)
>>The researchers reported a peculiar fluoride-IQ relationship that only appeared within a narrow exposure window (1.60-2.50 mg/L), with no effects at either lower or higher concentrations. <<
I don't understand where you are pulling these results from. Table 3 which shows effect size and confidence intervals for which a urinary fluoride level is correlated with IQ decrease. The concentration range of 1.60 - 2.50mg/L is only used with regards to urinary fluoride levels in the study write-up, maybe I missed it on my skim though.
>>This non-monotonic relationship contradicts fundamental dose-response principles and suggests either methodological flaws or the presence of uncontrolled confounding variables.<<
Maybe I'm just simple-minded but are you using a bunch of fancy words here to steamroll your audience into believing chemicals will always exhibit a linear relationship between exposure level and harm level? You must hate the non-monotonic relationship between health and table salt consumption.
>>This unusual pattern doesn't make biological sense and suggests problems with the study's methods.<<
An incredibly bold way to throw out a study you don't like. If I could throw out any study which didn't make intuitive sense to me, the field of theoretical physics will be decimated overnight.
5. Rocha-Amador et al. (2007)
>>This Mexican study stands out for several methodological strengths in examining both fluoride and arsenic exposure. <<
We agree here.
>>In plain terms: This study was well-designed and controlled for many important factors, but because fluoride and arsenic levels were so closely linked in the water supply, it's impossible to tell which substance might be affecting IQ scores.<<
You say this knowing an uninformed audience thinks arsenic is bad. The correlation between IQ and arsenic at those concentrations of arsenic is even less established than the correlation between IQ and fluoride. While it is a significant consideration when evaluating the study results, it does not at all invalidate the study! You are misrepresenting this study to your audience.
My city located in a red county in Oregon recently voted to remove fluoride from its municipal water supply. Numerous public comments to city councilors from citizens who’ve done their own research using biased sources based on the faulty results you’ve highlighted here were used to put the question on the ‘24 ballot. Politics played a big part in higher Covid-19 mortality rates in red states and the fluoridation of municipal water seems to be following a similar trend to the detriment of public health as well.
My worst string of dental caries happened when I lived in an area without fluoridated water! I wish I had known it wasn't fluoridated so I could have been doing fluoride rinses back then. Expensive and painful personal lesson!
Dear, Dr. Steir & Nina Munoz. Well done. At first I had thought "Who drinks from the tap these days" . But of course the answer is all of those folks who can't afford alternatives. The ones most likely to not get proper dental care.
Thanks for the thoroughness of your article.
When will the madness end?
Please keep up the good work.
With much respect, HELENLOUISE J.
Dear Dr. Steier, please excuse my error on spelling of your name. My maiden name is similar. Stolmeier. Not many folks have eier in their last name.
Google experts strike again! I am grateful for knowledgeable people like you who help to explain results in an understandable and meaningful way instead of fear-mongering. Thank you!
First off, shouldn't the burden of proof for a health intervention be on the pro-intervention side? Are you not arguing that water fluoridation does not need to be studied in high quality expensive trials because the quality of these studies showing damage is questionable? How can you make this argument? It is precisely people like you who are trying to guarantee that no one ever does a high quality study of the issue at hand.
Nonetheless, let's dig into some of your 'refutations'. I selected a few at random and skimmed through the papers.
1. Khan et al (2015)
>>The study's design cannot establish causation<<
As you know, it is not feasible to establish causation within a single study of this scope. The study is not seeking to do so. Your invocation of this fact only serves to misrepresent the actual findings of the study to your audience.
>>the researchers failed to control for essential variables like socioeconomic status, parental education, and other environmental exposures.<<
How so? Because it's not a double blind RCT with careful sample selection? Are you not specifically advocating against carrying out such a trial in a developed country with this article you've written? The authors appear to be doing the best they can with the resources feasibly available to them. The authors selected two sample groups with "similar socio-economic status, standards of living, quality of education, medical facilities, and cultural status". It would have been nice to see this characterized more scientifically, but it's a bold misrepresentation of the study to say "they failed" to control for these things.
>>With only 429 children and measurements taken at a single time point, the study cannot account for historical exposure variations or demonstrate a clear causal relationship.<<
OK. I don't know who you're reading that is citing this paper in this way, but the paper raises valid concerns about the effect of fluorosis on childhood IQ. You did not effectively debunk this citation at all.
3. Yu et al. (2018)
>>The researchers reported a peculiar fluoride-IQ relationship that only appeared within a narrow exposure window (1.60-2.50 mg/L), with no effects at either lower or higher concentrations. <<
I don't understand where you are pulling these results from. Table 3 which shows effect size and confidence intervals for which a urinary fluoride level is correlated with IQ decrease. The concentration range of 1.60 - 2.50mg/L is only used with regards to urinary fluoride levels in the study write-up, maybe I missed it on my skim though.
>>This non-monotonic relationship contradicts fundamental dose-response principles and suggests either methodological flaws or the presence of uncontrolled confounding variables.<<
Maybe I'm just simple-minded but are you using a bunch of fancy words here to steamroll your audience into believing chemicals will always exhibit a linear relationship between exposure level and harm level? You must hate the non-monotonic relationship between health and table salt consumption.
>>This unusual pattern doesn't make biological sense and suggests problems with the study's methods.<<
An incredibly bold way to throw out a study you don't like. If I could throw out any study which didn't make intuitive sense to me, the field of theoretical physics will be decimated overnight.
5. Rocha-Amador et al. (2007)
>>This Mexican study stands out for several methodological strengths in examining both fluoride and arsenic exposure. <<
We agree here.
>>In plain terms: This study was well-designed and controlled for many important factors, but because fluoride and arsenic levels were so closely linked in the water supply, it's impossible to tell which substance might be affecting IQ scores.<<
You say this knowing an uninformed audience thinks arsenic is bad. The correlation between IQ and arsenic at those concentrations of arsenic is even less established than the correlation between IQ and fluoride. While it is a significant consideration when evaluating the study results, it does not at all invalidate the study! You are misrepresenting this study to your audience.
My city located in a red county in Oregon recently voted to remove fluoride from its municipal water supply. Numerous public comments to city councilors from citizens who’ve done their own research using biased sources based on the faulty results you’ve highlighted here were used to put the question on the ‘24 ballot. Politics played a big part in higher Covid-19 mortality rates in red states and the fluoridation of municipal water seems to be following a similar trend to the detriment of public health as well.