Previously known as Physicians and Scientists for Responsible Genetics PSRGNZ - Charitable Trust
As required under the new 2005 Charities Act, PSGR has reregistered as a charitable trust.


16 November 2017

To all Members of the New Zealand Parliament   


For the sake of a tooth

Michael E Godfrey MBBS, FACAM, FACNEM, Director, Bay of Plenty Environmental Health Clinic, TAURANGA


This letter is to request that all Members of Parliament work cooperatively with all other Members of Parliament from across the political spectrum, to ensure a safe and proper approach to the use of fluoride.  We ask this in the interest of protecting New Zealanders.

The Science has changed

An important study published this year in the journal Environmental Health Perspectives by a team of investigators at the Universities of Toronto, McGill, and the Harvard School of Public Health, has found a significant association between fluoride exposure in pregnancy and lower measures of intelligence in children [1]. The US National Institute for Health funded this US$3 million study to specifically investigate developmental neurotoxicity.

The study is the first by the U.S. Government in 60 years into potential adverse neurological effects. It adds to the published evidence indicating widespread adverse effects from fluoride involving all stages in life from pre-birth to old age. They include, amongst other effects, confirmed neurological impairment including: loss of IQ; hypothyroidism; musculo-skeletal fluorosis diagnosed as arthritis; and dental fluorosis. This element is present due to an unlimited consumption of fluoridated water; in toothpaste; in tea; in pharmaceuticals; and in the commercial food chain.

Historical Fact

The premise of a fluoride dental benefit was based on an inadequately researched hypothesis in the 1940s that was enthusiastically endorsed by American commercial and political interests with a need to sanitise a toxic industrial waste product from the atomic, aluminium and fertiliser industries.  The sugar industry also directly lobbied to support fluoridation. However, subsequent dental research involving a total that exceeded 200,000 children from the USA (1990) Australia (1996-2013) and now in New Zealand (released in March 2017) has confirmed at best a reduction of one filling per child [2].

Dental Decay

Dental decay is totally due to excessive sugar consumption and nutrient deficiencies. Notably, the Maori population on their ancestral diets had no dental decay. This changed to 40 percent within a generation of adopting foods based on sugar and white flour.  No amount of fluoride will change this whilst Coca-Cola remain cheaper than milk.

The latest Medsafe (December 2014) Guidance document for labelling of fluoride tablets renders the uncontrolled availability of fluoridated water at up to 1mg/L and even toothpaste at significant variance with Medsafe limits that specifically included these  instructions [5]:

1.  Do not use in children under 6 years of age

1.2.  Do not use in pregnancy

The Dental Association's fluoride promotion ignores this important medical directive.

Adverse neurological effect of fluoride

The findings of this latest study have major implications in that an increase in urine fluoride of 1 mg/L was associated with a significant drop in IQ of 5 to 6 points. To put this into perspective the Mexican women subjects had urine fluoride between 0.5 and 1.5 mg/L with an average of 0.9 mg/L.  Loss of IQ in the children was found over this entire range of mother's urine fluoride when the children were tested at age 4.  A study presented in 2015, reported that the mean urinary fluoride concentration was 0.82 mg/L amongst 55 pregnant women residing in the fluoridated community of Palmerston North [3]. Thus, mean daily urinary excretion in pregnant women in a fluoridated community in NZ appears to be virtually the same. The range of fluoride exposures is likely to be well within the range in fluoridated New Zealand and thus directly applicable to areas with artificial fluoridation. 

A study by Broadbent (2015) reportedly found no association between fluoridated water and IQ [4].  However, unlike the Mexican research, this observational study did not quantify exposure using established bio-monitoring matrices such as urinary or plasma fluoride levels. Neither did this study investigate prenatal exposure and this could be critical.

Potential inverse cost benefits

The Ministry for Health (MoH) has yet to properly balance the cost-saving of a tooth against the potential adverse health effects. Whilst a reduction in IQ of this magnitude could logically contribute to socioeconomic inequalities and a decreased quality of life, the evidence for musculo-skeletal fluoride effects or arthritis cost this country over $3 billion in 2010 [6,7]. Fluoride induced hypothyroidism has also been identified [8] with subsequent increased incidences of obesity and diabetes that are also an ever-increasing costly social problem.

The Republic of Ireland (RoI), with a similar population to NZ as well as similar soft water, has had mandatory water fluoridation for 50 years. Despite this dental decay rates are still high. The RoI has double the rate of diabetes of unfluoridated Northern Ireland. The prevalence of diabetes is equally high in the USA, Australia, NZ and Singapore all with extensive water fluoridation. The annual financial burden of treating diabetes alone in the RoI has been estimated at over 10 percent of the health budget or Euros 1.4 billion [9] and NZ is no different.

Over the past 60 years the population has been increasingly exposed to fluoride, mainly sourced from industrial wastes, yet paradoxically no public health bio-monitoring has been undertaken. Any cost-benefit of artificial fluoridation with potentially a minimal one tooth saved per child needs to be compared with the international evidence of widespread and increasing chronic illnesses in every country with an artificial fluoridation policy.


This latest study importantly replicated previous research [10] by identifying that ingesting fluoride at levels essentially identical to those found in New Zealand mothers, resulted in neurological impairment in their offspring. Any risk of this is obviously unacceptable and potentially preventable if the Medsafe guidelines were implemented.

The accumulating body burden of fluoride is associated with multi-system debilitating illnesses.

The deliberate fluoridation of municipal water supplies appears to be unscientific, inappropriate, ineffective, and a significant health cost to the nation.

Dental decay, diabetes and obesity are all caused by excessive sugar intake.


Michael E. Godfrey MB.BS.

and the Trustees of Physicians and Scientists for Global Responsibility New Zealand Charitable Trust



1 Bashash M, Thomas D, Hu H, et al. 2017. Prenatal Fluoride Exposure and Cognitive Outcomes in Children at 4 and 6-12 Years of Age in Mexico. Environmental Health Perspectives. 2017 Sept. 19th.


3 Brough L, Jin Y, Coad J, Weber JL et al. Fluoride intakes in pregnant women in Palmerston North, New Zealand Joint Annual Scientific Meeting of the Nutrition Society of NZ and the Nutrition Society of Australia Dec 2015

4 Broadbent JM, Thomson WM, Ramrakha S, Moffitt TE et al. Am J Public Health. 2015 January; 105(1): 72-76. Published online 2015 January. doi:  10.2105/AJPH.2013.301857

5 (accessed January 2017)

6 Report by Access Economics Pty Limited for: Arthritis New Zealand. The economic cost of Arthritis in New Zealand in 2010. Available online:  (accessed on 14 March 2016).

7 Waugh TD, Godfrey ME, Limeback H and Potter W. Black tea source, production and consumption: Assessment of health risks of fluoride intake in New Zealand. J. Environ. and Public Health June 2017.

8 Peckham S, Lowery D, Spencer S. J Epidemiol Community Health Published Online First: doi:10.1136/ jech-2014-204971

9 Nolan JJ, O'Halloran D, McKenna TJ, Firth R and Richmond S. The cost of treating type 2 diabetes (CODEIRE). Ir Med J. 2006;99(10):307-310

  1. Grandjean P and Landrigan PJ Neurobehavioural effects of developmental toxicity. Lancet Neurol 2014; 13: 330-38