April 2012 – Cancer Epidemiology: Fluoride in drinking water and osteosarcoma incidence rates in the continental United States among children and adolescents. Levy Leclerc BS.

“Basically, Levy and Leclerc used a very weak methodology, weakened it further by failing to even look at the fluoridation in relationship to their SEER data set, and chose to omit the two SEER states that might have helped show there was a positive relationship between fluoridation and osteosarcoma.  They completely misunderstood the main finding of Bassin, and perhaps that was why they erroneously chose to omit Hawaii and Utah.  They thought Bassin found an unusual age-incidence curve in those exposed to fluoridation (nothing could be further from the truth), so they thought they needed to only look at states where there was fairly widespread fluoridation and omit those that had little fluoridation.

It has very little scientific weight compared to Bassin’s study.”  See full critque by Chris Neurath.

August 2011 – Chester Douglass’ long-promised study is published, and fails to address or refute Bassin’s finding of age-related fluoride exposure risk to males. (See media releases)

Journal of Dental Reseach: An assessment of bone fluoride and osteosarcoma: Kim FM, Hayes C, Williams PL, Whitford GM, Joshipura KJ, Hoover RN, Douglass CW; National Osteosarcoma Etiology Group

Osteosarcoma is a type of bone cancer that often afflicts young people, particularly males.  Although it is a rare cancer making up only 3% of all cancers, it is a very serious cancer, resulting in death or amputation to save the victim’s life.

A number of studies have shown a link between fluoridation and osteosarcoma, the most recent published in April 2009. To date, no study has refuted this link. In July 2011 Chester Douglass finally published his long-promised study. But it failed to even address age-related risk, let alone disprove it.

The most famous study is the Bassin study:

Age-specific fluoride exposure in drinking water and osteosarcoma (United States).
Bassin EB, Wypij D, Davis RB, Mittleman MA. Cancer Causes Control. 2006 May;17(4):421-8.

This was published in 2006 after being deliberately suppressed by the pro-fluoridation lobby. The study showed a 500-700% increase in osteosarcoma for boys exposed to fluoridated water between the ages of 6 and 10. This confirmed earlier studies by the New Jersey Department of Health in 1992, and the US Public Health Service in 1991.

A number of animal studies support these findings.

Approximately six NZ teenage males die each year from osteosarcoma. On the weight of evidence, it appears the majority are due to fluoridation.

Serum Fluoride and Sialic Acid Levels in Osteosarcoma.
Sandhu R, Lal H, Kundu ZS, Kharb S. Biol Trace Elem Res. 2009 Apr 24.

This study found higher blood-fluoride levels in subjects with osteosarcoma than patients with other bone tumours or other musculo-skeltal disorders.

The researchers measured blood fluoride levels in three equal groups of age-matched and sex-matched patients. Group one had osteosarcoma; group two had non-osteosarcoma bone tumors; and group three had musculo-skeletal pain.

They concluded “(T)his report proves a link between raised fluoride levels in serum and osteosarcoma,” (emphasis added)

It is not clear why blood-fluoride levels would be elevated at the time the osteosarcoma appeared, as exposure to fluoride at this time was shown to be irrelevant by the Bassin study. It may be that fluoride accumulated at a younger age is being released, but this is speculation at this point.

The Bassin Study

The Environmental Working Group (EWG), the most respected and scientifically based of all environment groups in the USA, has called on the USA’s National Toxicology Program to study and recommend on the extensive evidence and new evidence on the bone cancer-fluoride link. The clear implication of the call is that it would be prudent to stop new fluoridation, and possibly existing fluoridation, while the NTP produces its report.

The EWG’s letter begins:

“The Environmental Working Group (EWG), the most respected and scientifically based of all environment groups in the USA, has called on the USA’s National Toxicology Program to study and recommend on the extensive evidence and new evidence on the bone cancer-fluoride link. The clear implication of the call is that it would be prudent to stop new fluoridation, and possibly existing fluoridation, while the NTP produces its report.”

The petition to the NTP at the National Institutes of Health (with full scientific evidence), is posted on the home page of Environment Working Group [ http://ewg.org/ ].

The study, completed by Dr. Elise Bassin, showed a strong correlation between exposure to fluoridated water from the ages of 6 – 10 and teenage osteosracoma in teenage males. The research was completed in 2001 as a PhD thesis, but suppressed by her supervisor until exposed in 2005. It was published in the internationally recognised journal, Cancer Causes and Control, in 2006.

Bassin demonstrated that exposure during rapid bone growth – age 6-10 and especially 7-8 – resulted in an increased risk of osteosarcoma 10 years or more later. But only for males. The analysis showed definitively no such link for females, supporting the reliability of the analysis.

Click here to view the chart (opens in a new window).

Osteosarcoma accounts for about 3% of cancers, primarily in children. 50% of sufferers die. The remainder generally need affected limbs amputated to survive. Would you sacrifice your son to this so that who won’t take responsibikity for their or their children’s dental health may have 1/2 a filling less (the most that the York Review would concede possible)?

Early concerns about cancer

Concern about the ability of fluoride to cause bone cancer arose first in a 1977 NAS review of fluoride safety, where the academy committee expressed concerns about a high (13.5 percent) incidence in bone structure defects in the population of one of the nation’s first fluoridated communities, Newburgh, New York, compared to a 7 percent rate in the non-fluoridated Kingston community. At that time, the NAS recommended a full study of fluoride’s potential to cause osteosarcoma in young boys. The resulting U.S. Public Health Service (USPHS) study was completed in 1991 and found a significant association between fluoride exposure and bone cancer in boys.

The 1991 USPHS study was based on data collected by the National Cancer Institute from 1973 through 1987. The first phase compared osteosarcoma rates in males under 20 years of age in fluoridated communities, with non-fluoridated communities in Iowa and around Seattle. The researchers found a 79 percent increase in osteosarcoma from 1973 through 1987 in fluoridated communities, compared to a 4 percent decrease over the same time period in non-fluoridated communities. A second phase of the study expanded the analysis nationwide, and found that the rates of osteosarcoma were 57 percent higher in the fluoridated communities than in communities with non-fluoridated water supplies (Hoover 1991).

As a follow-up to the USPHS study, the New Jersey Department of Health (NJDH) commissioned a similar study at the municipal level based on an individual’s residence at the time of osteosarcoma diagnosis. The NJDH found that young males living in fluoridated communities had significantly higher rates of osteosarcoma than young males living in non-fluoridated areas; males 10-19 years old in fluoridated areas were 6.9 times more likely to develop osteosarcoma than those in non-fluoridated areas. According to the study authors, the findings “support the importance of investigating the possible link between osteosarcoma and overall ingestion of fluoride” (Cohn 1992).

Some experts questioned the significance of the NTP study findings when it was published, citing the lack of an association between osteosarcoma and the length of time that individuals were exposed to fluoride in tap water. The Bassin study demonstartes that it is not the total length of exposure, but the timing of that exposure, that is critical. The overall weight of the scientific evidence, in fact, provides compelling evidence that fluoride exposure during distinct mid-childhood periods of rapid bone growth is a much better indicator of osteosarcoma risk, than total duration, or average lifetime exposure.

Fluoridation promoters try to avoid recognising this landmark study by claiming “we cannot change our position because of just one study when earlier studies found no connection.” This is a deliberate falsification of the situation. Of the studies that have failed to find an association between fluoride in tap water and bone cancer (Operskalski 1987; McGuire 1991; Freni and Gaylor 1992; Moss 1995; Gelberg 1995), most have basic methodological issues that readily explain the negative findings. For instance, four of the five studies referenced above failed to analyze for age-specific effects, making it impossible for them to find such an association. The other (Operskalski) used friends and neighbors as controls, which can produce a phenomenon called overmatching, where “detecting a benefit or risk for fluoride would be unlikely” (Bassin 2001, pg 78).

These studies are irrelevant as summarized by Bassin:

“Prior studies have primarily evaluated fluoride exposure at the time of diagnosis or as an average lifetime exposure, and have not evaluated exposures at specific ages during growth and development when cell division is occurring rapidly” (Bassin 2001, pg 69).

Consequently, although gleefully quoted by pro-fluoridationists as a sound reason for burying their heads in the sand, the studies do not in any way negate the Bassin findings.

Non-epidemiological studies

Beyond human epidemiologic studies, the core supporting evidence includes the following:

  • The two animal cancer bioassays conducted to date each found an increase in extremely rare bone tumors among male test animals in two species, rats and mice, exposed to fluoride (Maurer 1990; Maurer et al 1993; NTP 1990).
  • Six separate studies have found that fluoride causes genetic mutations in humans (Meng 1995, 1997; Lazutka 1999; Sheth 1994; Wu 1995; Joseph 2000); additional studies show that humans appear to be more sensitive to the genotoxicity of fluoride than rodents (Kishi 1993).
  • The link between fluoride and osteosarcoma during periods of rapid growth is biologically highly plausible. Fluoride is a proven mitogen, meaning that it increases the proliferation of osteoblasts (bone formation) during periods of rapid skeletal growth (Gruber 1991; Kleerekoper 1996; Whitford 1996). As put by Dr. Bassin in her doctoral thesis: “It is biologically plausible that fluoride increases the rate of osteosarcoma, and that this effect would be strongest during periods of rapid growth, particularly in males” (Bassin 2001, pg 79).

Animal studies found bone cancer in male test animals

Only two long-term animal cancer bioassays with fluoride have ever been conducted; one by the National Toxicology Program (NTP), and another by Procter and Gamble, which involved both rats and mice. Both found an increase in rare bone tumors among male animals exposed to fluoride.

In the NTP study, a dose-dependent increase of osteosarcoma was seen in the bones of fluoride-treated male rats (NTP 1990). These findings are highly significant for a number of reasons:

  • Osteosarcoma is extremely difficult to produce in rats; the only other environmental agent known to induce osteosarcoma in rats is high doses of radiation;
  • The levels of fluoride in the treated rats’ bones were in the same range as fluoride found in human bones;
  • Bones are the site of fluoride accumulation, and;
  • The osteosarcomas were evident before the end of the study, indicating an age dependent vulnerability similar to that seen in human males.

The study authors were unequivocal about their findings: “The neoplasms were clearly malignant (one metastasized to the lung) and there was complete agreement concerning the diagnoses at both the quality assessment and Pathology Working Group stages of the histopathology review.”

Curiously, a 1993 National Research Council (NRC) review appeared to miss the importance of the findings. In characterizing the significance of the findings the NRC stated simply: “The equivocal result of osteosarcoma in male rats was not supported by results in females in the same study” (NRC 1993). This is an extraordinary statement given the prescient concerns for young males raised 16 years earlier by the NAS (in 1977), and the available epidemiologic data available at that time (Hoover 1991; Cohn 1992). Increased osteosarcoma in males, as identified in the Hoover and Cohn studies, is precisely the result that the 1977 NAS panel was concerned about.

In a 2002 review of fluoride toxicity the World Health Organization offered a more reasoned assessment of the results of the NTP rat study: “Such a (dose-dependent) trend associated with the occurrence of a rare tumour in the tissue in which fluoride is known to accumulate cannot be casually dismissed” (WHO 2002).

An additional animal study was conducted by Procter & Gamble, using both mice and rats. The study found a large, dose-dependent increase in rare bone tumors (osteomas) in fluoride-treated mice (Maurer 1993). The second part of the study, in rats, again found bone tumors and a rare tooth tumor in the treated rats but not the controls (Maurer et al. 1990). Apparently this study was discounted because most of the tumors, although rare, were not yet malignant.