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The Case Against Water Fluoridation

The Case Against Water Fluoridation. Paul Connett, PhD Professor Emeritus of Environmental Chemistry St. Lawrence University, Canton, NY Director, Fluoride Action Network www.Fluoride ALERT .org pconnett@gmail.com Ministry of Health, NZ, March 22, 2011. Outline of talk.

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The Case Against Water Fluoridation

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  1. The Case Against Water Fluoridation Paul Connett, PhD Professor Emeritus of Environmental Chemistry St. Lawrence University, Canton, NY Director, Fluoride Action Network www.FluorideALERT.org pconnett@gmail.com Ministry of Health, NZ, March 22, 2011

  2. Outline of talk 1. Fluoridation is a poor medical practice 2. Fluoridation is unethical 3. The evidence of any benefit is very weak 4. There is no adequate margin of safety to protect the brain from harm and other KNOWN health effects 5. Politics versus Science 6. Other health concerns

  3. Part 3.The evidence of benefitis very weak

  4. Comparing Countries

  5. Most countries don’t fluoridate their water, but their kids’ teeth are as good as those that do

  6. SOURCE: World Health Organization. (Data online)

  7. Comparing US States

  8. Percent 50 USA States and DC National Survey of Children's Health.http://mchb.hrsa.gov/oralhealth/portrait/1cct.htm U.S. Department of Health and Human Services, Health Resources and Services Administration, Maternal and Child Health Bureau. The National Survey of Children's Health 2003. Rockville, Maryland: U.S. Department of Health and Human Services, 2005 http://www.cdc.gov/oralhealth/waterfluoridation/fact_sheets/states_stats2002.htm

  9. Comparing US Communities

  10. NIDR conducted the largest survey of tooth decay ever conducted in the US (1986-7) • The teeth of over 39,000 children in 84 communities were examined.

  11. Thelargest US survey of tooth decay 3.4 DMFS NF 2.8 DMFS F Average difference (for 5 - 17 year olds) in DMFS

  12. Brunelle and Carlos, 1990 3.4 DMFS NF 2.8 DMFS F Average difference (for 5 - 17 year olds) in DMFS = 0.6 tooth surfaces (5 surfaces to a tooth)

  13. Weaknesses in Brunelle and Carlos study 1) Brunelle and Carlos did not report statistical significance of the 0.6 tooth surface decay difference 2) Nor did they adjust for possible delayed eruption of teeth in fluoridated areas- William Kiel of Alamo Heights, Texas, made this adjustment…

  14. Recent Trends in Dental Caries in U.S. Children and the Effect of Water Fluoridation by J.A. Brunelle and J.P. Carlos Journal of Dental Research February 1990 (Volume 69, Special Issue, Pages 723-727) Original Data – Age Based Shifted Data – Post-Eruption Based* Adjusted for one year Delayed eruption of teeth William Kiel, Alamo Heights. Mean DMFS Mean DMFS *Fluoridated data was shifted back by one year; e.g. age 6 Fluoridated aligns with age 5 unfluoridated, etc.

  15. Studies in Australia have found even less saving than O.6 DMFS! Spencer et al. (1996) found a saving in two states of ONLY 0.12 – 0.3 permanent tooth surfaces. Armfield and Spencer (2004) found no statistically significant difference in tooth decay in the permanent teeth between children in South Australia who had drunk fluoridated water all their lives and those who had drunk bottled or tank water.

  16. “The magnitude of [fluoridation’s] effect is not large in absolute terms, is often not statistically significant, and may not be of clinical significance.” SOURCE: David Locker for the Ontario Ministry of Health & Long Term Care, 1999

  17. Studies in NZ John Colquhoun (studies:1984- 1997) De Liefde, 1998 The difference in tooth decay in permanent teeth was “clinically meaninglesss” Recent studies reported in MOH (2010), “Our Oral Health” Wellington versus Canterbury saving of 1 DMFS (2.4 – 1.4) Lee and Dennison, 2004, MOH p.28.

  18. Studies in NZ (MOH) “… studies found that 9-10 year olds continuously exposed to water fluoridation had half the dental caries experience of those who had not in Auckland (Kanagaratnam et al 2009) and Southland (Mackay and Thomson 2005). Another Auckland study of 9-year-olds similarly found lower levels of dental caries in fluoridated areas than non-fluoridated areas (Schluter et al 2008)” p.28, MOH, 2010

  19. Schluter et al 2008 Prevalence of caries: Deciduous teeth, prevalence: F = 54.9%, NF = 62.0 % (p=0.05) Saving = 7.1% Permanent teeth prevalence F = 15.9%, NF = 11.7% (p=0.14) Permanent teeth worse in F-areas but not statistically significant Nothing here looks like a saving of half of the dental caries in either the deciduous or permanent teeth (nor was a corrcction made for delayed eruption of teeth in F city).

  20. Mackay and Thomson, 2005 Residence in F area up to age 9 Deciduous teeth: dmfs None 5.11 Intermittent 4.29 Continuous 3.42 Saving = 5.11 – 3.42 = 1.69 dmfs % saving = 1.69/5.11 x 100 = 33%

  21. Mackay and Thomson, 2005 Residence in F area up to age 9 Permanent teeth: DMFS None 1.22 Intermittent 1.18 Continuous 0.70 Saving = 1.22 – 0.70 = 0.52 DMFS % saving = 0.70/1.22 x 100 =43%

  22. NZ studies • In neither of these two NZ studies was there any attempt to control for the possible delayed eruption of teeth in F communities • Even so the best result indicates a saving of ONLY 0.5 of a single permanent tooth surface • There are either 4 or 5 surfaces to a tooth. • There are 128 tooth surfaces when all the teeth (except the wisdom teeth) have erupted.

  23. Percentage savings versus absolute savings • Proponents frequently report their findings as percentage savings. This can be very deceptive. • We saw in this last study that a saving of one half of a permanent tooth surface (note there are 4 or 5 surfaces to a tooth) equates to a percentage saving of 43%. • The latter sounds more impressive to the general public.

  24. Kanagaratnam et al., 2009 “no significant relationship was found between residential fluoridation history and dental caries in the permanent dentition. This may be partly because, at 9 years of age, only some of the permanent teeth are present, and differences in caries prevalence and severity with differing exposures to fluoride may become more obvious in older children who have more permanent teeth for a longer time (29)….

  25. Kanagaratnam et al., 2009 …a longer time (29).The significantly higher proportion of girls (whose teeth erupt at an earlier age) with permanent teeth caries compared with boys exemplifies this limitation.”

  26. Australian studies The most impressive studies demonstrating a small difference in tooth decay between fluoridated and non-fluoridated communities have come from Australia from Adelaide University (Spencer, Armfield etc). They controlled for several confounding factors to reach a small saving BUT they did not control for delayed eruption of the teeth in F-areas.

  27. Delayed eruption in F areas “The DA (dental age) of the AUS and UK populations was found to be different (Fig. 5). The AUS population had a 0.82 year delay in their DA compared to the UK population. This difference was compared and was found to be very statistically significant (P < 0.001).” Peirisi et al. International Journal of Paediatric Dentistry 2009; 19: 367–376

  28. Recent Trends in Dental Caries in U.S. Children and the Effect of Water Fluoridation by J.A. Brunelle and J.P. Carlos Journal of Dental Research February 1990 (Volume 69, Special Issue, Pages 723-727) Original Data – Age Based Shifted Data – Post-Eruption Based* Adjusted for one year Delayed eruption of teeth William Kiel, Alamo Heights. Mean DMFS Mean DMFS *Fluoridated data was shifted back by one year; e.g. age 6 Fluoridated aligns with age 5 unfluoridated, etc.

  29. Important recent studies Komarek et al., 2005 (controlled for delayed eruption of teeth in F-communities). Found no difference in tooth decay between F and non-F communities. Warren et al., 2009 (measured tooth decay as a function of individual exposure to fluoride). Found no relation between tooth decay and amount of fluoride ingested.

  30. An explanation for weak evidenceof benefit in very large studies The major benefits of fluoride are TOPICAL not SYSTEMIC. (CDC, 1999, 2001). In other words fluoride works on the outside surface of the tooth not from inside the body Fluoridation should have ended in 1999!

  31. Fluoride’s main benefit is TOPICAL. It works on the outside of the tooth. “Its actions primarily are topicalfor both adults and children." Centers for Disease Control, 1999 "Fluoride's predominant effect is posteruptive and topical." Centers for Disease Control, 2001

  32. Schluter et al 2008 “The effect of fluoride on dental caries is due primarily to the topical effect of fluoride after the teeth have erupted into the oral cavity. The harmful effects of fluoride are due to it systemic absorption during tooth development resulting in dental fluorosis … The dose-response relationship is linear and for every 0.01 mg/kg bodyweight increase in exposure, there is a corresponding detectable increase in the population (Ellwood and Fejerskov, 2003).”

  33. Part 4.There is no adequate margin of safety to protect everyone from knownharmful effects of fluoride

  34. A KEY QUESTION When fluoride is damaging the baby’s growing tooth cells (causing dental fluorosis) what is it doing to its other developing tissues?

  35. The baby’s developing brain The baby should NOT be exposed to fluoride of up to 250 times the level of fluoride that occurs in mothers milk

  36. Arvid Carlsson Nobel Prize for Medicine, 2000 “One wonders what …an increase in the exposure to fluoride, such as occurs in bottle-fed infants …may mean for the development of the brain and the other organs…” 1978

  37. National Research Council (2006): Fluoride & the Brain “it is apparent that fluorides have the ability to interfere with the functions of the brain.”

  38. Fluoride and the Brain Many more studies on the brain have been published since the NRC review The panel reviewed FIVE IQ studies

  39. Human studies • As of 2011, there are 24 published studies (from China, Iran, India and Mexico) indicating that moderate to high fluoride exposure is associated with lowered IQ in children • See FluorideAlert.org/brain

  40. Xiang et al. (2003 a,b) • Compared children in two villages ( <0.7 ppm versus 2.5 - 4.5 ppm F in water) • Controlled for lead exposure and iodine intake, and other key variables (NOTE: both lead exposure and low iodine also lower IQ). • Found a drop of 5-10 IQ points across the whole age range • The whole IQ curve shifted for both males and females

  41. Xiang et al. (2003 a,b) MALES

  42. Xiang et al. (2003 a,b) FEMALES

  43. Xiang et al. (2003 a,b) • Estimated that IQ in children lowered at • 1.9 ppm fluoride in water (threshold)

  44. There is no adequate margin of safety • If fluoride is associated with lowering IQ of children at 1.9 ppmin a small population study we need to apply a safety factor to protect the whole population of children • Normally we use a safety factor of 10 to do this • If we assume that the Chinese children were drinking one liter of fluoride per day the dose that lowered IQ was 1.9 mg/day • That would mean to protect the intelligence of ALL the children in a large population a safe dose would be 0.19 mg/day (1.9 divided by 10)

  45. Mini sensitivity analysis • If the Chinese children were drinking 0.5 liter, LOAEL for lowered IQ = 0.95 mg/day. Safe dose to protect whole population = 0.095 mg/day. • If the Chinese children were drinking 2 liters, lowered IQ at 3.8 mg/day. Safe dose to protect whole population = 0.38 mg/day (less than two glasses of water) • If we reduced margin of safety to 5(instead of10) • Safe dose = 0.19- 0.76 mg/day (equivalent to 190 -760 ml of water at 1 ppm a day)

  46. Xiang et al. (2010) • Xiang et al. elaborated on their 2003 study. • Added in more details of methods etc. • Added in data showing an association between plasma levels of fluoride and lowered IQ. • Accepted for publication by Environmental Health Perspectives the journal of the National Institute of Environmental Health Sciences (NIEHS) • NIEHS is an agency of the US Department of Health and Human Services (DHHS). • Pre-publication copy of this article published online • Article withdrawn because Xiang had published some of the data before (conflicts with EHP policy)

  47. Xiang et al. (2010) • Please note: • Xiang et al. (2010) paper was NOT withdrawn because the methodology was considered inadequate • The methodology was PEER REVIEWED and the study considered acceptable for publication in the leading US environmental health journal.

  48. Ding et al. 2011 (J. Hazardous Materials) • “Mean value of fluoride in drinking water was 1.31 ±1.05mg/L (range 0.24–2.84).” • “ Conclusions • Overall, our study suggested that low levels of fluoride exposure in drinking water had negative effects on children’s intelligence... • The results also confirmed the dose–response relationships between urine fluoride concentrations and IQ scores…”

  49. Ding et al. 2011 Fig 2. The relationship between IQ differences and urine fluoride concentrations. Multiple linear regression model was carried out to confirm the association with urine fluoride exposure and IQ scores (F=9.85, p < 0.0001)

  50. Ding et al. 2011 • “an increase in the urine fluoride concentration of 1 mg/L associated with a decrease of 0.59 IQ scores.”

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