Perhaps. But given that we have several candidate mechanisms, and experiments showing that fluoride really does cause hyperactivity in rats, I wouldn't write this off too quickly.
Correlation link only at this point. From the abstract:
> Overall state water fluoridation prevalence (not distinguishing between fluoridation types) was also significantly positively correlated with state prevalence of ADHD for all but one year examined. [...] The relationship between fluoride exposure and ADHD warrants future study.
Still, it will be interesting to see what more comes out of this.
After reading the title and the paper's abstract, this seems to me like just one more instance of the many, many statistics that are strongly correlated with overall economic development of a society, and hence strongly correlated with each other without any causal link. In this case, the relevant factors would be "water fluoridation prevalence" and "capacity of doctors to diagnose ADHD", which are both almost certainly correlated with the overall economic status of a society (not of individuals).
It is naive postulation to dismiss the paper for not addressing a variable, when you have not even read the paper to know whether they addressed the variable.
Further, your cursory read of the abstract somehow missed the clause "after controlling for socioeconomic status"
I think the 'controlling for socioeconomic status" was just between the states, not an all encompassing control of economic status. Two states with a similar rise in economic activity and ADHD wouldn't fail afoul of the control. Maybe.
This article might hold up, but my past experience with statistics in medical papers does not give me great hope. For a while, my job was to review the math in interesting papers (well, interesting to who ever flagged it) from medical journals. In the three years that I did this, I encountered exactly zero that didn't commit some grave statistical sin.
It would be a statistical sin to determine that after seeing N papers with an error, that the N+1th would certainly have an error. Extrapolating the specific error without even seeing the paper is closer to rhetoric than science.
I was bothered by this study, and particularly this bit:
"After adjusting for sociodemographics, other drug use and childhood depression, we found no significant associations between lifetime use of psychedelics and increased likelihood of past year serious psychological distress, mental health treatment, suicidal thoughts, suicidal plans and suicide attempt, depression and anxiety."
It seems they test life time usage, yet only "past year" serious psychological distress, mental health treatment, suicidal thoughts, suicidal plans and suicide attempt, depression and anxiety.
Can I get your opinion on whether that "past year" applies to just "serious psychological distress" or all the terms, including: "mental health treatment, suicidal thoughts, suicidal plans and suicide attempt, depression and anxiety".
It would seem to me that "past year" applies to all of the terms. In my opinion the study misses the rather obvious problems that cause somebody to quit psychedelics permanently, allowing them to recover. Those that quit long ago would not report issues because they didn't happen in the immediate 12 month period previous.
Also acquaintances of mine who have ended up permanently hospitalised, are obviously not going to be part of a survey like this.
>Past year mental health indicators new to this study were suicide thoughts, suicide plan...[etc]
So, it looks like 'past year' applies to all of the terms. I think the study was looking at the long term effects, so if people who quit long ago didn't report any issues, that would support the thesis that 'taking psychedelics doesn't affect long term mental health'. I'm generally not a fan of studies about illegal activity that use voluntary surveys, but this one doesn't look poorly run. However, once you start putting maths to psychology, things get weird very quickly and it's difficult to tell what's valid and what isn't.
Thank you for taking the time. I disagree, I don't think they mention "long term" mental health anywhere. They just say mental health without qualifying it. In fact they only mention "long-term" benefits.
I find it really objectionable that it's titled:
"Psychedelics not linked to mental health problems or suicidal behavior: A population study"
while looking at whole lifetime usage and comparing with past year effects.
If there was suicidal behaviour("successful" or otherwise) and mental health problems in the immediate aftermath of taking psychedelics over a lifetime, they don't really have any way of capturing that information unless it's happened in the last 12 months. We agree that the "past year" applies to all of the terms.
Just seems really irresponsible to me, but I'm clearly biased.
no it wouldn't. it would be a good guess based on his experience. not a statistical sin at all, the events are related, the guys doing the work make mistakes all the time and the odds they get it right this time are low.
"Hierarchical and multivariate regression analyses were conducted to examine the relationship between artificial water fluoridation prevalence and ADHD prevalence after controlling for natural water fluoridation prevalence and SES, and SES respectively."
...
"Moreover, results did not appear to be confounded by
socioeconomic status because they remained consistent after controlling for this variable."
...
"Moreover, artificial water fluoridation prevalence [compared with SES] even appeared to be the more robust predictor."
Even if you have a problem with the stat analysis (i don't), The fact that it's a stronger predictor than SES is quite damning regardless of controls.
But socioeconomic status might not be the confounding variable. It could be something more like "civilization" or "the amount of pro-health resources in the community". Fluoride and child doctors are both things that contribute to health, and different communities make different decisions about how much importance they want to place on childhood health.
I also suspect that fluoridation does not track with socioeconomic status. I mean, look at how Portland Oregon's got rid of fluoridation.
Nevertheless, reading the article, it does look like they have rat studies that show that fluoride in rats causes mental impariment.
Things to note: they soaked cultures of rat hippocampus neurons in various concentrations of sodium fluoride. They didn't make the rats drink fluorinated water. It's difficult for fluoride to cross the blood brain barrier.
> Fluoride can readily cross the placenta, accumulate in the infant brain and easily exert
neurotoxic effects, such as decreasing norepinephrine in the parietal and occipital lobes,
decreasing serotonin in the parietal lobe and increasing serotonin in the frontal and occipital
lobes [42-45].
So maybe it passes the blood-brain barrier more easily in infants or in utero?
Also if you search for "rats' in the original article, http://www.ehjournal.net/content/pdf/s12940-015-0003-1.pdf then you'll see them referencing studies that has rats drink or be injected with fluoride. They weren't referencing the study you linked.
You don't have to wonder. You can follow the link right there in the Newsweek article, and find it's a different study. Here it is for your convenience: http://www.ncbi.nlm.nih.gov/pubmed/7760776
From the abstract: "For prenatal exposures, dams received injections (SC) of 0.13 mg/kg NaF or saline on gestational days 14-18 or 17-19. Weanlings received drinking water containing 0, 75, 100, or 125 ppm F for 6 or 20 weeks, and 3 month-old adults received water containing 100 ppm F for 6 weeks."
I didn't miss that clause. Controlling for SES is not trivial. And they only controlled for it at the state level. I'm just saying that the variables they measured seem like the kind of ones that are strongly correlated with economic development, so looking for a week association between the variables themselves is like looking for a needle in a haystack. Even if you eliminate 90% of the haystack (i.e. control for most, but not all, of SES effects), finding the needle doesn't get much easier.
Or looking at it another way, my point is that since most correlations like this turn out to both have economic development as a common cause rather than being themselves causally related, I require extraordinary evidence to the contrary before I believe it.
Not to mention that ADHD can't be diagnosed in the same manner as, say, a broken bone since it is (to make a simplification) a bunch of behaviors that suggest that maybe this individual's dopamine response is flatter than normal, sometimes aided in diagnosis with motor / memory tests.
I would guess that this would make it difficult to control for misdiagnosis, and I would also guess that there are a fair number of misdiagnosed kids with ADHD seeing as about 2/3 of them "grow out" of it last time I checked.
(Note: I have ADHD. It was obvious as a kid, but I wasn't diagnosed until I was 24 due to my parents religiosity. I know there are valid childhood diagnoses, and that we've made quite a lot of progress with understanding and being able to diagnose neuropsychiatric disorders. There also seem to be quite a few "social pressure" and "fad" diagnoses of ADHD in the USA -- if this study wants to be taken seriously, they might consider repeating it in other countries.)
It's been a while since I read up on the subject for personal reasons, but wasn't one of the problems with ADHD for a long time that getting accurate numbers was hard because of frequent misdiagnosis (actually just diagnosing a depression instead). Especially, because the symptoms were still considered debatable at that time? So maybe, diagnosis shifted dramatically during that time as well?
Hearsay/conspiracy theory... but I heard that fluoride doesn't help your teeth and that a general increase in hygiene occurred the same time that fluoride.
I also heard that it is a byproduct of processing aluminium and they coaxed the government to put it into water rather than disposing of it responsibly.
Pure bullshit. Fluoride (F-) is a weak base. Dental plaque produces acid (H+) which is one cause of tooth decay. F- + H+ <-> HF. The Fluoride neutralizes some of the acid to reduce tooth decay.
That's not the main way it protects the teeth. If you just wanted to neutralize the acids, you could rinse/drink with a buffer such as milk. Flouride works by integrating with your teeth. It forms a mineral that it is more resistant to acid attack than the mineral teeth are made of naturally.
Yes, the biggest benefit is when the tooth is forming. It's like boro-silicate glass (pyrex) or steel; some atoms in the crystalline structure of the base material are replaced with others, which improves the overall strength of the result. So, like boron improves glass and carbon improves iron (to make steel) then fluoride improves the tooth structure.
Ugh. I hate to think of all of the "I told you so's" from the misguided people in Portland who continually vote against fluoridating the water with no actual scientific basis for doing so.
Or think more broadly. Fluoridation of water carries a massive public health benefit, particularly to poorer families. Given the frequency of exposure across locations and generations, what negative effect it has appears to be extraordinarily very mild at best, while the benefit it provides is significant.
Whoops. I guess I'm uninformed on this one, but I thought the whole "Flouridation is bad" thing had some basis in truth? There have been a few other articles about it on HN.
Well, four votes within 60 years isn't exactly "continually", but I'll cede that point. Lots of Portlanders believe that fluoride is just fine, thank you (though the most recent vote was 60%-40%, sadly.)
Studies showing that fluoride causes hyperactivity in rats go back to the 90s, according to the article. Maybe the people in Portland should be given the benefit of the doubt.
I understand the whole fluoride issue has been tainted by conspiracy theories, but honestly, it's not that unscientific to think that ingesting a known endocrine disruptor might have a biological effect.
Out of curiosity, do you have references on fluoride and endocrine disruption?
Further, I disagree regarding whether anyone should receive 'the benefit of the doubt'; we should defer to the many public health studies on the benefits of fluoride.
It's in the Newsweek article, which discusses several possible biological mechanisms for problems from fluoridation, complete with sources, many of which are direct links to studies. Perhaps read it?
It's in the Newsweek article, which discusses several posible biological mechanisms
for problems from fluoridation, complete with sources, many of which are direct links
to studies. Perhaps read it?
No need to be rude here. I was curious about what the mechanism would be - even the reference pointed out in the Newsweek article[1] doesn't propose a model for how fluoride might disrupt endocrine levels.
I guess you have the results of a detailed poll which checked the Portland public's knowledge of the issues or are you being a tad patronizing in your assumptions?
I think science articles should be banned from HN. The userbase is clearly not educated well enough to deal with the issues. It only produces comments from armchair scientists conjuring up whatever pet theory they can explain away the results with. Comments like the classic freshman stats quote "correlation does not equal causation", or the standard response starting with "Judging from the abstract", or the always informative "I didn't read the paper, but what if they forgot to control for X?"
The only topic that gets worse comments than science on HN is gender issues.
Edit: and killed by mods. From +25 at the top to the bottom
A healthy dose of skepticism is the reason I DO read Hacker News. There's no limit to the studies trumpeted in the news with inaccurate titles/conclusions. HN calls them out. Notwithstanding posts from folks with fashionably cynical attitudes.
I think so too.
I'm not as smart as you guys,community college.
I usually lurk and look forward to spin deconstruction here.
its one of the reasons I love reading comments here
The only topic that gets worse comments than science on HN is gender issues.
I think you're unfair there. If you want to see a diversity of opinions, that's exactly what we have--the fact that you disagree with one side or the other is quite your own problem.
> For all the intellectual firepower of people in the tech community, there is a curious strain of anti-intellectualism that comes forth in projects like this; an eagerness to discount the expertise of people who have studied a subject for their entire lives, just because they weren't CS majors. It's like trying to send a man to the moon without working with any aerospace engineers. I honestly do not understand it.
Some members of the userbase even commit sins like generalizing from a few cases to the entire population or even make assumptions about unattested facts like, say, the educational qualifications of hypothetical people who haven't even commented yet. If only there were some sort of mechanism which would allow us to vote on which comments we felt were insightful and showed expertise with the subject matter...
Absolutely not!! This would be a blatant act of censorship--and to what end? You'll see the same junk science on Reddit anyway.
The feedback from the HN community on science articles is some of the best on the web. It honestly comprises about a third of the reason I visit. I wouldn't know where else to get that.
Granted, I may have a different perspective given that I did a biochem undergrad and can read primary literature. Some of my experience and frustration with the popular media coverage and editorial behavior has given me a lens with which to evaluate coverage of other disciplines. But shouldn't we expect everyone here to have or develop a similar critical thinking patten? Why do we need to treat our community with baby gloves?
Obviously we can't ban science articles, but the point you're raising is important. Reductionist dismissal of new work based on partial understanding of the marginally related is a tell-tale sign of the middlebrow. It is epidemic in communities like this. I don't think there's anything more vital to intellectual maturity than learning to recognize those dismissive reflexes in oneself and inhibit them. That is the essence of an open mind.
There's an analogy to startup investing here. The habit of dismissing the easily dismissable—the obviously lame, the obviously bad idea—guarantees failure even though it's almost always right. This is what the masters of the art keep trying to tell us.
I marked this subthread as off-topic because it's off topic; it doesn't mean we don't agree.
The post has been hammered by both the flamewar detector and a ton of user flags. We turned the former off, but not the latter. Doing more would probably make things worse.
Speaking personally, I think on average it takes me about 30 to 80 articles from a divergent field to get a grasp of what's going on.
At the same time, when I go into forums like these, I'm aware of what kind of crowd I'm going to get: while most people give their off-handed dismissal "Omg, that n size. 120 is way too small for something so important."
What we might need is a general and informal rule that science-based posts should have at least several studies in good standing.
Yeah, in the same sense that Satoshi Nakamoto's name correlates strongly with that of a randomly-chosen 64-year-old engineer trying to enjoy a modest, quiet retirement in the Bay Area.
The "truthiness" factor of anything published in Newsweek lies somewhere between Mother Goose and the Brothers Grimm.
The existence is generally accepted, it's included in any larger medical catalog[1], there are standard tests (UTAH test), there's a wide array of literature, but management seems to be a problem.
[1]: it's classified with critieria since ICD-9, which was defined in 1978.
The most interesting tidbit in the article was this:
About 90 percent of the fluoride that is added to the water takes the form not of pharmaceutical grade sodium fluoride but ... fluorosilicic acid ... This material is a byproduct of phosphate fertilizer manufacturing ... several studies have suggested that this form of fluoride can leach lead from pipes. ...other work shows that children in fluoridated areas have elevated blood lead levels, and fluoride may also increase the absorption of lead into the body... Lead itself is a potent neurotoxin and has been shown to play a role in ADHD.
What is the likelihood that in areas with lower spending on municipal water that lead pipes are still used and they use the cheapest for of fluoridation available?
The concern over lead in the water system is largely focused on lead-based solder in copper pipes. That is restricted largely to postwar homes up until the emergence of PVC and PEX plumbing in the 80's.
Plastic pipes can put endocrine disruptors like BPA/BPS and other nasties in the water. It's pretty common for new piping to leave noticable odor/taste for a while.
72 comments
[ 3.5 ms ] story [ 135 ms ] thread> Overall state water fluoridation prevalence (not distinguishing between fluoridation types) was also significantly positively correlated with state prevalence of ADHD for all but one year examined. [...] The relationship between fluoride exposure and ADHD warrants future study.
Still, it will be interesting to see what more comes out of this.
Further, your cursory read of the abstract somehow missed the clause "after controlling for socioeconomic status"
This article might hold up, but my past experience with statistics in medical papers does not give me great hope. For a while, my job was to review the math in interesting papers (well, interesting to who ever flagged it) from medical journals. In the three years that I did this, I encountered exactly zero that didn't commit some grave statistical sin.
Again: the paper might be correct, but past experience has taught me to be skeptical.
I was bothered by this study, and particularly this bit:
"After adjusting for sociodemographics, other drug use and childhood depression, we found no significant associations between lifetime use of psychedelics and increased likelihood of past year serious psychological distress, mental health treatment, suicidal thoughts, suicidal plans and suicide attempt, depression and anxiety."
It seems they test life time usage, yet only "past year" serious psychological distress, mental health treatment, suicidal thoughts, suicidal plans and suicide attempt, depression and anxiety.
Can I get your opinion on whether that "past year" applies to just "serious psychological distress" or all the terms, including: "mental health treatment, suicidal thoughts, suicidal plans and suicide attempt, depression and anxiety".
It would seem to me that "past year" applies to all of the terms. In my opinion the study misses the rather obvious problems that cause somebody to quit psychedelics permanently, allowing them to recover. Those that quit long ago would not report issues because they didn't happen in the immediate 12 month period previous.
Also acquaintances of mine who have ended up permanently hospitalised, are obviously not going to be part of a survey like this.
Do you agree or disagree with any of that?
>Past year mental health indicators new to this study were suicide thoughts, suicide plan...[etc]
So, it looks like 'past year' applies to all of the terms. I think the study was looking at the long term effects, so if people who quit long ago didn't report any issues, that would support the thesis that 'taking psychedelics doesn't affect long term mental health'. I'm generally not a fan of studies about illegal activity that use voluntary surveys, but this one doesn't look poorly run. However, once you start putting maths to psychology, things get weird very quickly and it's difficult to tell what's valid and what isn't.
I find it really objectionable that it's titled:
"Psychedelics not linked to mental health problems or suicidal behavior: A population study"
while looking at whole lifetime usage and comparing with past year effects.
If there was suicidal behaviour("successful" or otherwise) and mental health problems in the immediate aftermath of taking psychedelics over a lifetime, they don't really have any way of capturing that information unless it's happened in the last 12 months. We agree that the "past year" applies to all of the terms.
Just seems really irresponsible to me, but I'm clearly biased.
Even if you have a problem with the stat analysis (i don't), The fact that it's a stronger predictor than SES is quite damning regardless of controls.
I also suspect that fluoridation does not track with socioeconomic status. I mean, look at how Portland Oregon's got rid of fluoridation.
Nevertheless, reading the article, it does look like they have rat studies that show that fluoride in rats causes mental impariment.
Things to note: they soaked cultures of rat hippocampus neurons in various concentrations of sodium fluoride. They didn't make the rats drink fluorinated water. It's difficult for fluoride to cross the blood brain barrier.
> Fluoride can readily cross the placenta, accumulate in the infant brain and easily exert neurotoxic effects, such as decreasing norepinephrine in the parietal and occipital lobes, decreasing serotonin in the parietal lobe and increasing serotonin in the frontal and occipital lobes [42-45].
So maybe it passes the blood-brain barrier more easily in infants or in utero?
Also if you search for "rats' in the original article, http://www.ehjournal.net/content/pdf/s12940-015-0003-1.pdf then you'll see them referencing studies that has rats drink or be injected with fluoride. They weren't referencing the study you linked.
From the abstract: "For prenatal exposures, dams received injections (SC) of 0.13 mg/kg NaF or saline on gestational days 14-18 or 17-19. Weanlings received drinking water containing 0, 75, 100, or 125 ppm F for 6 or 20 weeks, and 3 month-old adults received water containing 100 ppm F for 6 weeks."
So...
Or looking at it another way, my point is that since most correlations like this turn out to both have economic development as a common cause rather than being themselves causally related, I require extraordinary evidence to the contrary before I believe it.
I would guess that this would make it difficult to control for misdiagnosis, and I would also guess that there are a fair number of misdiagnosed kids with ADHD seeing as about 2/3 of them "grow out" of it last time I checked.
(Note: I have ADHD. It was obvious as a kid, but I wasn't diagnosed until I was 24 due to my parents religiosity. I know there are valid childhood diagnoses, and that we've made quite a lot of progress with understanding and being able to diagnose neuropsychiatric disorders. There also seem to be quite a few "social pressure" and "fad" diagnoses of ADHD in the USA -- if this study wants to be taken seriously, they might consider repeating it in other countries.)
Any chance I can get a more elaborate correction?
http://www.portlandmercury.com/portland/the-sanest-arguments...
I understand the whole fluoride issue has been tainted by conspiracy theories, but honestly, it's not that unscientific to think that ingesting a known endocrine disruptor might have a biological effect.
Further, I disagree regarding whether anyone should receive 'the benefit of the doubt'; we should defer to the many public health studies on the benefits of fluoride.
[1] http://www.nap.edu/openbook.php?record_id=11571&page=265
The only topic that gets worse comments than science on HN is gender issues.
Edit: and killed by mods. From +25 at the top to the bottom
I think you're unfair there. If you want to see a diversity of opinions, that's exactly what we have--the fact that you disagree with one side or the other is quite your own problem.
> For all the intellectual firepower of people in the tech community, there is a curious strain of anti-intellectualism that comes forth in projects like this; an eagerness to discount the expertise of people who have studied a subject for their entire lives, just because they weren't CS majors. It's like trying to send a man to the moon without working with any aerospace engineers. I honestly do not understand it.
The feedback from the HN community on science articles is some of the best on the web. It honestly comprises about a third of the reason I visit. I wouldn't know where else to get that.
Granted, I may have a different perspective given that I did a biochem undergrad and can read primary literature. Some of my experience and frustration with the popular media coverage and editorial behavior has given me a lens with which to evaluate coverage of other disciplines. But shouldn't we expect everyone here to have or develop a similar critical thinking patten? Why do we need to treat our community with baby gloves?
There's an analogy to startup investing here. The habit of dismissing the easily dismissable—the obviously lame, the obviously bad idea—guarantees failure even though it's almost always right. This is what the masters of the art keep trying to tell us.
I marked this subthread as off-topic because it's off topic; it doesn't mean we don't agree.
The post has been hammered by both the flamewar detector and a ton of user flags. We turned the former off, but not the latter. Doing more would probably make things worse.
At the same time, when I go into forums like these, I'm aware of what kind of crowd I'm going to get: while most people give their off-handed dismissal "Omg, that n size. 120 is way too small for something so important."
What we might need is a general and informal rule that science-based posts should have at least several studies in good standing.
The "truthiness" factor of anything published in Newsweek lies somewhere between Mother Goose and the Brothers Grimm.
[1]: it's classified with critieria since ICD-9, which was defined in 1978.
About 90 percent of the fluoride that is added to the water takes the form not of pharmaceutical grade sodium fluoride but ... fluorosilicic acid ... This material is a byproduct of phosphate fertilizer manufacturing ... several studies have suggested that this form of fluoride can leach lead from pipes. ...other work shows that children in fluoridated areas have elevated blood lead levels, and fluoride may also increase the absorption of lead into the body... Lead itself is a potent neurotoxin and has been shown to play a role in ADHD.
What is the likelihood that in areas with lower spending on municipal water that lead pipes are still used and they use the cheapest for of fluoridation available?
This freaks me out a little.
For "other nasties" see http://grist.org/living/is-it-safe-to-drink-water-out-of-pla... "Some of the latest research coming out of the NSF project tested several brands of PEX tubing for chemical leaching – and found it."