"And finally fluoride supplement from the family can easily tip the scale dramatically in total consumption which make the comparison pointless."
In groups of 100? What's the percentage of people that routinely consume toxic levels of fluoride from dental supplements (that study ran four months)? People don't generally eat toothpaste or drink mouthwash but I'm sure it happens. I just wouldn't assume that it would happen often enough to give you poison data.
" Like with many other minerals, too little is actually harmful, there is a right dosage and too much is again showing toxicity."
This is where I'm at on tap water...I assert that LOW-DOSAGE exposure over extended periods of time is bad and I assert that in the US there are area's that have incredibly high-doses of fluoride in tap water (at least 6 parts per million). Which is bad all around. Water is controlled at the jurisdiction level and there's NO guarantee that you're getting below the recommended dose of fluoride. I'm of the opinion that it's completely nuts to put this stuff in the drinking water and the Indian, Harvard, and recent NIH papers appear to back this up.
"Why do the papers against do not mention this, do not mention any theorical model to explain their findings, do not correct for socio-demographics factors when we know that intelligence is generally very poorly related to any other variables except those ones which disproportionately explain it?"
I agree with this...In the first study I could not tell if they controlled for socio-economic status. They identified villages with varying levels of fluoride and called it a day. The Harvard study did though. And the American study I linked to seemed to control for this as well...And they all came back with results that were similar...Repeated low-doses of fluoride have detrimental effects to development health.
Form the harvard study:
"We carried out a pilot study of 51 first-grade children in southern Sichuan, China, using the fluoride concentration in morning urine after an exposure-free night; fluoride in well-water source; and dental fluorosis status as indices of past fluoride exposure. We administered a battery of age-appropriate, relatively culture-independent tests that reflect different functional domains: the Wide Range Assessment of Memory and Learning (WRAML), Wechsler Intelligence Scale for Children-Revised (WISC-IV) digit span and block design; finger tapping and grooved pegboard. Confounder-adjusted associations between exposure indicators and test scores were assessed using multiple regression models. "
In groups of 100? What's the percentage of people that routinely consume toxic levels of fluoride from dental supplements (that study ran four months)? People don't generally eat toothpaste or drink mouthwash but I'm sure it happens. I just wouldn't assume that it would happen often enough to give you poison data.
" Like with many other minerals, too little is actually harmful, there is a right dosage and too much is again showing toxicity."
This is where I'm at on tap water...I assert that LOW-DOSAGE exposure over extended periods of time is bad and I assert that in the US there are area's that have incredibly high-doses of fluoride in tap water (at least 6 parts per million). Which is bad all around. Water is controlled at the jurisdiction level and there's NO guarantee that you're getting below the recommended dose of fluoride. I'm of the opinion that it's completely nuts to put this stuff in the drinking water and the Indian, Harvard, and recent NIH papers appear to back this up.
"Why do the papers against do not mention this, do not mention any theorical model to explain their findings, do not correct for socio-demographics factors when we know that intelligence is generally very poorly related to any other variables except those ones which disproportionately explain it?"
I agree with this...In the first study I could not tell if they controlled for socio-economic status. They identified villages with varying levels of fluoride and called it a day. The Harvard study did though. And the American study I linked to seemed to control for this as well...And they all came back with results that were similar...Repeated low-doses of fluoride have detrimental effects to development health.
Form the harvard study: "We carried out a pilot study of 51 first-grade children in southern Sichuan, China, using the fluoride concentration in morning urine after an exposure-free night; fluoride in well-water source; and dental fluorosis status as indices of past fluoride exposure. We administered a battery of age-appropriate, relatively culture-independent tests that reflect different functional domains: the Wide Range Assessment of Memory and Learning (WRAML), Wechsler Intelligence Scale for Children-Revised (WISC-IV) digit span and block design; finger tapping and grooved pegboard. Confounder-adjusted associations between exposure indicators and test scores were assessed using multiple regression models. "