Monday, October 6, 2014

Irish Dental Colleges Promoters of Water Fluoridation Do they really know what they are talking about?

I wish to respond to some of the comments and misrepresentations made by Professor  June Nunn, Prof Martin Kinirons, Dr. John Walsh and Dr Peter Gannon, President of the Irish Dental Association in their letter published in the Irish Examiner and Irish times (dated October 1st and  6th 2014). In this letter the authors clearly suggest that children eating fluoride toothpaste is the primary cause of dental fluorosis among children in Ireland. This view is entirely incorrect. In 2005, the European Journal of Paediatric Dentistry reported that children who always received a fluoridated water supply were 38 times more likely to have fluorosis, while children who began using toothpaste between 12 and 18 months were 2 times more likely to have fluorosis [1]. These are facts that Prof Nunn and her colleagues should be keenly aware of, if they are not it would be surprising. They should also be aware that Irish dental research has demonstrated that the prevalence of dental fluorosis is up to 25 times higher in Ireland among children in fluoridated compared to non-fluoridated communities[ 2-4].

As far back as 1984, the WHO acknowledge that dental fluorosis only occurs when excess fluoride in ingested during the first seven years of life [5]. It therefore provides absolutely no indication what the fluoride exposure of an adolescent or adult may be. Prof Nunn and her colleagues should also be aware  that the increase in chronic fluoride intoxication of infants occurred in Ireland from the late 1980s onwards. This was primarily due to changes in infant feeding practices. Not only were more infants drinking powdered infant formula made with fluoridated tap water, but the use of whole cow’s milk as infant milk; which was the primary source of infant food among children aged 6-12 months up to the early 1980s, almost ceased entirely from the mid-1980s onwards. This resulted in significantly extending the period of chronic fluoride intoxication among infants as cow’s milk contains about 45 times less fluoride than infant formula made with fluoridated tap water. In the period when this change occurred, published data from Ireland documented that the prevalence of dental fluorosis among children increased by up to seven fold (700%) [6]. Recent risk assessments conducted internationally have concluded that babies fed formula milk prepared with fluoridated water will exceed the established upper tolerable safe level for fluoride exposure for healthy adults [7,8]. This view is supported by UK Medical Research Council (2002) when they reported that individuals most likely to have excessive fluoride intakes are formula-fed infants living  in fluoridated communities [9].

In 2004, an Irish study published in the international journal Caries Research estimated the infant dietary exposure to fluoride during the first four months of life for infants in fluoridated communities living across Ireland [10]. The exposure of infants exceeded the adequate intake level recommended by the U.S. Institute of Health by a staggering 1700% [11], as well as exceeding the Tolerable Upper Intake Level for healthy adults, as recommended by the European Food Safety Authority (EFSA)[12].  In 2006, the EFSA reported that the fluoride dose given to babies fed formula milk prepared with fluoridated tap water (at Irish levels) would be 100 to 500 times greater than that of breast fed infants [12]. Perhaps, Prof Nunn and her colleagues are not aware of these facts?

In this regard,  it is interesting to note what the World Health Organization (WHO) has stated about exceedances of Tolerable Daily Intakes. In 2006, the WHO advised that tolerable daily intakes should not be exceeded, and where they may occur authorities should provide bottled water for bottle fed  infants to avoid overexposure [13]. Alternatively, the WHO recommended that "such steps can be used on a household basis to reduce exposure and allow the continued use of the supply without interruption." [13] This last point should also be of interest to Irish Water.  

Prof Nunn and her colleagues claim that decades of vigilance examining the potential side effects of community water fluoridation on the general health of populations have documented no medical side effects. This statement is perhaps correct, as in Ireland there has indeed been no scientific or medical evaluation of the wider health effects from mass fluoridation. As the WHO and other scientific bodies have noted, the only measure by which one can examine fluoride intake and exposure effectively is to measure individual fluoride exposure by measuring the fluoride level in plasma or urine [14]. However, one must also accurately measure the fluoride content of medications, foods and beverages consumed by individuals. The only published study examining fluoride exposure among Irish adults was published in 2010 by a medical physician in the UK [15].  The study included the results of analysis of fluoride levels in urine from adults in fluoridated communities in Donegal. While the study included data from over 1300 adults randomly selected in Scotland and England, the highest fluoride intake was observed among people in Donegal, followed by individuals living in fluoridated West Midlands. The vast majority of Irish subjects were noted to have excessive and potential harmful levels of fluoride exposure [15].

In Ireland, without question the highest source of fluoride intake among adults is tea. Almost twenty years ago the  School of Dental science at Trinity College, advised that the fluoride content of all tea brands sold in Ireland be measured in order to avoid excess fluoride intake by the population [16]. In the intervening years while millions of taxpayers monies have been channelled to the various dental colleges in Ireland,  not a single study has been published by any University providing the fluoride content of the most popular and widely  consumed beverage in Ireland. I wonder why? Perhaps, because such a study would highlight the clear fact that the majority of tea drinkers in Ireland are already getting sufficient or perhaps excessive fluoride from tea consumption alone. This would obviously make water fluoridation redundant, not to mention dangerous by its continuation. Recently, the public health authorities in Taiwan, when considering community water fluoridation, reported that such as measure was unnecessary due to the fluoride intake of the population from tea [17-18]. In 2013, a similar study conducted in the UK, measured the human exposure to fluoride from 38 of the most popular tea brands sold in the UK market, many of which are sold here in Ireland [19]. The findings of this study published in the journal of Food Research International found that when the fluoride level was measured in tea prepared with non fluoridated water, that tea consumers were exposed to chronic levels of fluoride that were detrimental to their health and general wellbeing [19].  In Ireland, we drink more tea than the UK or Taiwan, and the vast majority of people use fluoridated water to make tea. Perhaps Prof Nunn or her colleagues would explain this anomaly to the readers of the Irish Times and Irish Examiner?

From a medical surveillance point of view, I would like to know what research has been conducted in Ireland or New Zealand  to examine how the unprecedented increase in infant fluoride exposure, which occurred from the 1980s onwards, may or may not be a contributory factor to the staggering increases in childhood neurological disorders such as Autism or ADHD, as well as childhood metabolic and respiratory disorders, which have increased in the exact same time period as dental fluorosis to epidemic levels. Similar increases have only been found internationally among other countries with artificial fluoridation.  I wonder if Professor Nunn and her distinguished colleagues, given their personal stamp of approval for continued water fluoridation, would  be willing to indemnify parents and consumers in Ireland for chronic health disorders that may in the future be found to have been caused by chronic fluoride intoxication.

As for comparing the oral health of children in the Republic of Ireland with non fluoridated Northern Ireland, the basis of the argument by which profluoridionalists argue that we should continue with this experiment, the North South Survey of Children’s Oral Health in Ireland (2002) provided some interesting findings [20]. Among them was that 28% of children aged 8 years of age, in non-fluoridated communities in the Republic had better oral health than children in fluoridated communities [20]. Another 28 percent had the same level of oral health as children in fluoridated communities [20]. Of the remaining children surveyed the difference was 0.1 of a tooth [20]. As for variations in dental caries between Northern Ireland and the Republic of Ireland, at 12 years and 15 years of age respectively, the difference among children being caries free was just 8.5%, and 8.1%.[20].  These differences are remarkably  low, especially given the level of social deprivation in Northern Ireland in the 1980 and 1990’s. This fact was noted in the North South study when the authors reported that the prevalence of children poverty in Northern Ireland was almost double that for the Republic of Ireland [20].

The differences in oral health should also be assessed in the context that the study also found that the use of dental sealants on the teeth of children by dentists was significantly higher in the Republic compared to Northern Ireland, being present on some of the teeth of 70.4% of 12-year-olds in RoI compared to 54.9% of 12-year-olds in NI. Naturally, one would also expect that Prof Nunn and her distinguished colleagues are aware that the use of dental sealants has been described by the industry in Ireland, as preventative of dental caries, as noted in the findings of a HSE funded study published in 2010 [21]. One of the more interesting facts documented in the All-Ireland study was that the incidence of dental trauma among children was significantly higher in the Republic of Ireland compared to Northern Ireland [20]. This is worthy of special mention as in 2009, the Journal of Dental Research  acknowledged that not only does fluoride cause mineralization defects in teeth, but it also decreases enamel hardness, as well as making enamel more porous [22].  

So in essence, what the North South oral health study found was that with almost 100 percent higher rates of childhood poverty, and lower use of dental sealants, the difference in oral health between Northern Ireland and the Republic of Ireland was less than 10%.

What the All-Ireland study did not include, nor other dental studies ever conducted in Ireland, was information on water chemistry in particular calcium levels in drinking water. This is extremely relevant as calcium in water remineralises tooth enamel which is acknowledged to be protective in preventing dental caries [23], thereby helping to prevent tooth decay [24].  This fact has been demonstrated in Denmark where naturally levels of calcium in drinking water tested in over 250 water supplies were found to play a significant role in preventing dental caries among children [25]. A similar study of 400,000 children conducted in India [26], also found that the prevalence of dental caries and dental fluorosis was most severe and complex in calcium-deficient children.
As any scientist with an interest in water quality is aware, many of the drinking water supplies providing community potable water in Ireland would be classified as extremely soft. To try and compare oral health in communities without including this most basic evaluation means that the results are open to selective bias.

In ending I would suggest that as long as dental health practioners continue to promote artificial fluoridation without a basic understanding of the wider fluoride intake of the population from all sources including water, foods, pharmaceutical medications, dental products and occupational exposures in industry, their views on this subject should be intrepretated with extreme caution. There is also a clear confilict of interest for dental colleges who receive large amounts of funding from the Irish state to undertake research to promote fluoridation. Clearly without artificial fluoridation a considerable amount of research undertaken in these dental colleges would be unnecessary.

Yours sincerely

Declan Waugh

 [1] Harding, M. A., Whelton, H., O’Mullane, D. M., Cronin, M., & Warren, J. J. 2005, “Primary tooth fluorosis in 5-year-old schoolchildren in Ireland”, European Journal of Paediatric Dentistry : Official Journal of European Academy of Paediatric Dentistry , vol. 6, no. 3, pp. 155-161.
[2]  O'Mullane DM, Harding M, Whleton HP, Cronin MS, Warren JJ. Dental Fluorosis in Primary Teeth of 5-year-olds in Ireland. Paper presentation at American Association for Dental Research conference, San Antonio, USA in March 2003
[3]  Browne D, Whelton H, O‘ Mullane D, Oral Health Services Research Centre, University Dental School, Cork. Fluoride metabolism and fluorosis, Journal of Dentistry, Volume 33 Issue 3, March 2005, Pages 177-186
[4]  Verkerk, Robert H.J. The paradox of overlapping micronutrient risks and benefits obligates risk/benefit analysis, Journal of Toxicology, Feb 2010
[5]  World Health Organization, Prevention Methods and Programmes for Oral Diseases. WHO, TRS. 1984; 713.
[6]  Whelton H., Crowley E., O’Mullane D., Donaldson M., Kelleher V. and Cronin M. Dental caries and enamel fluorosis among the fluoridated and non-fluoridated populations in the Republic of Ireland in 2002. Oral Health Services Research Centre, University Dental School and Hospital, Cork
[7]  Critical review of any new evidence on the hazard profile, health effects, and human exposure to fluoride and the fluoridating agents of drinking water”, a report produced in 2011 by the SCHER (Scientific Committee on Health and Environmental Risks) of the European Commission.
[8]  Opinion of the Scientific Panel on Dietetic Products, Nutrition and Allergies on a request from the Commission related to the Tolerable Upper Intake Level of Fluoride, The EFSA Journal (2005) 192, 1-65, published on 7 June 2006.
[9]  Medical Research Council working group report: Water fluoridation and health, September 2002
[10]  Anderson W.A. Pratt I. Ryan M.R.  Flynn A. A probabilistic estimation of fluoride intake by infants up to the age of 4 months from infant formula reconstituted with tap water in the fluoridated regions of Ireland. Caries Res 2004;38:421-429
[11]  FNB (Food and Nutrition Board) (1997). Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D and Fluoride. Institute of Medicine National Academy Press, Washington DC
[12]  Opinion of the Scientific Panel on Dietetic Products, Nutrition and Allergies on a request from the Commission related to the Tolerable Upper Intake Level of Fluoride, The EFSA Journal (2005) 192, 1-65, published on 7 June 2006.
[13]  Guidelines for Drinking Water Quality. First Addendum to Third Edition, Volume I, Recommendations. World Health Organization, 2006.
[14]  World Health Organization (1986) Appropriate Use of Fluorides for Human Health [JJ Murray, editor]. Geneva: WHO
[15]  Mansfield, P. Fluoride Consumption: The Effect of Water Fluoridation.Research Report, Fluoride 43 (4) 223-231, October-December 2010.
[16]  Kavanagh D, Renehan J. Fluoride in tea--its dental significance: a review. J Ir Dent Assoc. 1998;44(4):100-5.
[17]  Shih-Chun Candice Lung, Pao-Kuei Hsiao and Kuang-Mao Chiang, Fluoride concentrations in three types of commercially packed tea drinks in Taiwan. Journal of Exposure Analysis and Environmental Epidemiology (2003) 13, 66 – 73
[18]  Shih-Chun Candice Lung, Hui-Wen Cheng and Chi Betsy Fu, Potential exposure and risk of fluoride intakes from tea drinks produced in Taiwan, Journal of Exposure Science and Environmental Epidemiology (2008)18, 158–166
[19]  Laura Chan et al. Human exposure assessment of fluoride from tea (Camellia sinensis L.) Food Research International 51 (2013) 564–570
[20]  H. Whelton, E. Crowley, D. O’Mullane, M. Harding, H. Guiney, M. Cronin, E. Flannery, V. Kelleher, North South Survey of Children’s Oral Health in Ireland 2002, Final Report – December 2006. Web:
[21]  Irish Oral Health Services Guideline Initiative. Pit and Fissure Sealants: Evidence-based guidance on the use of sealants for the prevention and management of pit and fissure caries. 2010.
[22]  Bronckers AL, Lyaruu DM, DenBesten PK - "The impact of fluoride on ameloblasts and the mechanisms of enamel fluorosis" J Dent Res 88(10):877-93 (2009)
[23]  Bronckers AL, Lyaruu DM, DenBesten PK - "The impact of fluoride on ameloblasts and the mechanisms of enamel fluorosis" J Dent Res 88(10):877-93 (2009)
[24]  Bruvo  M. Ekstrand K.,Arvin E.Spliid H.   Moe D.,Kirkeby    S.Bardow, A. Optimal Drinking Water Composition for Caries Control in Populations. JDR April 2008 vol. 87 no. 4 340-343
[25]  Bruvo  M. Ekstrand K.,Arvin E.Spliid H.   Moe D.,Kirkeby    S.Bardow, A. Optimal Drinking Water Composition for Caries Control in Populations. JDR April 2008 vol. 87 no. 4 340-343
[26]  S P S Teotia and M Teotia, Dental Caries: A Disorder of High Fluoride and Low Dietary Calcium Interactions (30 Years of Personal Research), Fluoride 1994; 27(2): 59-66

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