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The Fluoride Connection

Fluoride and the Placental Barrier
by Richard G. Foulkes, MD

 Kaj Roholm, in his study of fluoride intoxication in Danish Cryolite workers published in 19372 stated that he did not think that fluoride crossed the placental barrier. This opinion was based, primarily, on his failure to see fluorosis in the deciduous teeth of offspring. However, he was convinced that sufficient fluoride was passed through the milk of contaminated female workers to cause fluorosis in their children.

W.R. Cox, in 1953, published his personal account of multiple problems in Chinchillas that were attributed to high fluoride content of commercial animal feed.3 In 1951, when the probable cause was first identified, the MD and the chemist involved from the University of Oregon Medical School did not hesitate to state that fluoride penetrated the placental barrier in animals.

Fluoride and Fertility

One of the major problems encountered in these valuable commercial animals concerned fertility. After changing to a diet low in fluoride there were increases in the number of offspring born; the number of litters; and, the numbers born alive. The adult mortality rate decreased from 14.6% in 1951 to 3.3% in 1952. A number of abnormalities associated with the fluoride -contaminated feed were passed on through multiple generations.

It is of more than passing interest to note that although Cox found more than 1,400 studies that demonstrated adverse effects of fluoride in animals, both wild and domestic, there was a profound lack of knowledge and interest in these and in the implications for humans. This was especially true for possible soft tissue damage. It should come as no surprise that Cox, a layman, was shocked by the fact that those professionals exhibiting this lack of knowledge and disinterest were, at this time, spearheading the campaign to fluoridate public water supplies.

Freni, in a 1994 review,4 demonstrated decreased fertility in most animals studied. High doses (i.e., 430 ppm dietary fluoride in rats) showed anestrus with cumulative generational effects. This phenomenon, according to Freni's research, was first noted in 1933 and confirmed in 1984. His paper presents multiple examples that lead him to state, without equivocation, that fluoride easily crosses the placenta.

Freni participated in the 1991 Public Health Service review of the toxicity of fluoride and in the NTP study that emphasized the "cancer paradigm" discussed in Our Stolen Future.1

He was concerned about the implications of reproductive problems that were encountered. As a result, in 1991, he searched for reproductive studies that involved humans; but, he found none. It may come as a surprise to recognize that, after 46 years of fluoridation of drinking water, no study had taken place on the effect of fluoride on the developing fetus!

Freni, in a complicated study, compared the total fertility rate (TFR) in counties whose water supplies had at least 3 ppm fluoride. He found a negative TFR/fluoride association that fitted in with the toxicity data on animals.

Freni presented several theories to account for the lowered TFR. One, that fluoride lowers protein synthesis in osteoblasts; the other, that fluoride inhibits the adenylyl cyclase system in human spermatozoa.

Narayana and Chinoy referred in a 1994 paper5 to "the wide prevalence of infertility in the fluorosis-afflicted human population in India and other parts of the globe."

In their study, mature rats were treated with sodium fluoride (10mg/kg daily for 50 days). They found that fluoride interferes with androgenesis and adversely impaired the target organ structures. They suggested that the effect of fluoride may be on receptor sites. That is, fluoride may alter the concentration or configuration of the receptor, thereby inhibiting the action of testosterone. The similarity of this action to that of the hormone-disrupting chemicals, described in Our Stolen Future is obvious. (Our Stolen Future: Are We Threatening Our Fertility, Intelligence, and Survival? by Theo Colborn, et al. See review Feb/March 1997, TLfDP, #163/164 pg. 122.)

Fluoride and the Brain

The 1991 review, Fluoride Benefits and Risks, published by the USPHS6 states that there is "relative impermability of the blood-brain barrier to fluoride." No reference was made to fluoride effects on the brain.

In their 1978 book Fluoridation, the Great Dilemma, Waldbott, Burgstahler and McKinney7 describe the findings of Soviet physicians that 79% of patients with occupational fluorosis demonstrate dysfunction of subcortical axial non-specific structures of the brain.

Recent studies from China8,9 of the relationship between residence in endemic fluorosis areas in that country and IQ, contain references and discussions that indicate that this has been reported upon since 1989. Chinese studies indicate that the influence of a high fluoride environment on intelligence may occur early in development such as during the stages of embryonic life or infancy when differentiation and growth are more rapid. Ultramicroscopic study of embryonic brain tissue obtained from termination of pregnancy operations in endemic fluorosis areas showed "differentiation of brain nerve cells were poor, and brain development was delayed."8

The studies of Li et al.8 (soot fluorosis) and Zhao et al.9 (water supply fluorosis) compare the IQ status of children living in high fluoride areas to those in low fluoride areas. A graph constructed from Li's data shows a flattening, in the high fluoride population, of the normal "Bell Curve" distribution of IQ. The data of both the Li and Zhao studies show a shift of the curve toward the low IQ (<70 IQ) end in the high fluoride group. Both studies demonstrate that IQ is lower in all age groups in the high fluoride areas compared to those in the low fluoride areas. This finding suggests neurological damage in early development; that is, in utero. (see figures)

Other causes of lowered IQ appear to have been ruled out. These include: iodine deficiency; other congenital and acquired diseases; and cultural and ethnic differences. Dietary differences, which are known to play an important role in dental and skeletal fluorosis were not specifically accounted for although the authors mention "similar circumstances of material life."

These studies present evidence that, as is the case with infertility, brain dysfunction is prevalent in endemic fluorosis areas in countries outside of those in which deliberate fluoridation of drinking water is practiced. When the rising prevalence of dental fluorosis and the high dietary intakes of fluoride in fluoridated areas are taken into consideration, it may be said that large areas of endemic fluorosis have now been created in Canada, the US and other fluoridated countries pursuant to the policies of their respective Administrations. How much responsibility can be attributed to fluoride for the fertility and behavioral problems addressed by the authors of Our Stolen Future?

Are the fluoridated countries seriously looking for possible associations? It has been pointed to previously that research into the association between fluoride and human reproductive problems was not undertaken until 1991, 46 years after the start of fluoridation. What is the status with regard to possible links with the signs and symptoms of brain dysfunction?

In 1995, the 50th Anniversary of fluoridation in the US, and Canada, Mullenix, Denbesten et al. published a study of the neurotoxicity of sodium fluoride in rats.10 The authors state: "[T]his is the first laboratory study to demonstrate that CNS functional output is vulnerable to fluoride, that the effects on behaviour depend on the age at exposure and that fluoride accumulates in brain tissue."

The authors state further that "[E]xperience with other developmental neurotoxins prompts expectations that changes in behavioural function will be comparable across species, especially humans and rats."

This study demonstrated generic behavioural pattern disruption that the authors point to as indicative of a potential for motor dysfunction, IQ deficits and learning disabilities in humans. The authors point out that the plasma levels in their rat model (0.059 to 0.640 ppm fluoride) are similar to those reported in humans exposed to high levels of fluoride.

These authors refer to early Chinese studies in their paper and point out that high levels of fluoride in drinking water (i.e., 3 to 11 ppm) affect the nervous system directly without first causing physical deformations from skeletal fluorosis. This latter is currently used as the ultimate indicator of intoxication in discussions by proponents of fluoridation. "Still unexplained," the authors continue, "is the possibility that fluoride exposure is linked to subtle brain dysfunction."

The characteristics of the latter and the implications for society are well-described in Our Stolen Future even though the causative agents named are the hormone-disrupting chemicals.

Fluoride and "The Paradoxical Effect"

Our Stolen Future emphasizes the importance of the "paradoxical effect" in establishing the biological effects of toxins and, more particularly, the hormone-disrupting artificial chemicals. The authors credit Frederick Von Saal's investigations, which began in 1976, with the demonstration of a "U-shaped" response curve for DES. This illustrates the "paradoxical response"; that is, the response increases for a time and then diminishes with even higher doses.

This phenomenon in which a high dose may paradoxically cause less damage than a lower dose was described in a 1964 article by Schatz, Schalscha and Schatz.11 These authors show that paradoxical effects are not isolated phenomena but are broadly operative and of widespread importance in the biochemistry and physiology of many living systems under many different conditions.

Schatz et al. point to the different terms that investigators have used when they encountered this phenomenon. They describe the way in which conditioning leads investigators to think only in linear dose relationships thereby leading them to attribute deviations to experimental error or experimental variability.

The paper presents examples to illustrate that paradoxical effects are real, not artifacts. The authors state that "[P]aradoxical effects have been produced by radiation, temperature, mutagenic and carcinogenic chemicals, fluoride, steroid hormones, dextran, detergents, trace metals, herbicides, fungicides, insecticides, germicides, antibiotics, drugs and a host of other agents."

It is noteworthy that fluoride is included in the list of chemicals that may produce a paradoxical effect. They show, as an example, the curve of inhibition of human prostatic acid phosphatase. "[A]s the fluoride concentration is increased over a thousand-fold range, the extent of inhibition rises, attains a maximum that may approach 100% and subsequently falls."

In a recent paper,12 Schatz compared low level fluoridation with low level radiation: "[T]he occurrence of paradoxical effects with low level fluoridation and low level radiation shows that there is no threshold level below which fluoride and radiation are harmless."

Recognition of the importance of the paradoxical effect and the way in which research may be blinded by continued pursuit of the "linear dose relationship" and the "cancer paradigm" is essential if we are to determine the nature of all the elements that conspire to steal our future.


The similarities between the DES story, that is well-told in Our Stolen Future, and the story of the fluoridation of drinking water is striking. In both, numerous animal studies have been declared to be irrelevant. Both DES and fluoridation of water supplies have been shown to be without effect for the purposes claimed -- the prevention of abortion in the case of DES and of tooth decay in the case of fluoridation. DES continued to be prescribed for several decades after it had been discredited; fluoridation is being pushed now as hard as ever with the full support of the Administration, the Public Health Service and professional organizations representing Dentistry and Medicine, especially Pediatrics.

The failure of the US Food and Drug Administration (FDA) to act on DES is described in Our Stolen Future. This failure to act is repeated in the case of the human consumption of fluoride.

Is the future being stolen? Yes. There are many medical problems that can be attributed to the hormone-disrupting chemicals and other substances, including fluoride. Lowered fertility and brain dysfunction are just two of these for which there is mounting evidence.

The message is clear. Action is required immediately. However, such action must be inclusive not selective, as suggested in Our Stolen Future.


Richard G. Foulkes, BA, MD
Box 278
Abbotsford, British Columbia
V2S 4N9



1. Colborn, T., Dumanoski, D., Myers, J.P., Our Stolen Future, Dutton, Penguin Books U.S.A., New York, N.Y., 1996.

2. Roholm, K., Fluorine Intoxication - A Clinical-Hygienic Study, H.K. Lewis, London, 1937.

3. Cox, W.R., Hello Test AnimalsÉChinchillas or You and Your Grandchildren, The Olsen Publishing Co., Milwaukie, Wisc., 195l.

4. Freni, S.C., Exposure to High Fluoride Concentrations in Drinking Water is Associated With Decreased Birth Rates, Jour Toxicol and Environ. Health; 42; 109-121; 1994.

5. Narayana, M.V., Chinoy, N.J., Effect of fluoride on Rat Testicular Steroidogenesis, Fluoride, 27; 1; 7-12, 1994.

6. Dept of Health and Human Services, USPHS, Fluoride Benefits and Risks. February 1991.

7. Waldbott, G.L., Burgstahler, A.W., McKinney, H.L., Fluoridation, the Great Dilemma, Coronado Press, Lawrence, Kansas, 1978.

8. Li, X.S., Zhi, J.L., Gao, R.O., Effect of Fluoride Exposure on Intelligence of Children, Fluoride 28; 4; 189-192; 1995.

9. Zhao, Liang, G.H., Zhang, D., Wu, X., Effect of a High Fluoride Water Supply on Children's Intelligence, 1995 Pending Publication.

10. Mullenix, P.J., Denbesten, P.K., Schunior, A., Kernan, W.J., Neurotoxicity of Sodium Fluoride in Rats, Neurotoxicology and Teratology, 17;2; 169-177; 1995.

11. Schatz, A., Schalscha, E,B., Schatz, V., Soil Organic Matter as a Natural Chelating Material, Part 2, The Occurrence and Importance of Paradoxical Concentration Effects in Biological Systems, Compost Science 5; 22-30; Spring 1964.

12. Schatz, A., Low Level Fluoridation and Low Level Radiation - Two Case Histories of Misconduct of Science, Published by A. Schatz, PhD, Philadelphia, PA, 1996.
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