Fluoride & Genetic Damage

Fluoride & Genetic Damage

As pointed out in Chapter 4, all animals, including humans, are made up of cells. Each cell contains a nucleus, which is separated from the remainder of the cell by a nuclear membrane. Within the nucleus exist chromosomes, which contain DNA and protein. DNA is the body's master blueprint material. It is the genetic material that determines how the body is built. DNA specifies traits such as height, hair texture and color, number of fingers on each hand, blood type, and by means of its control of protein and enzyme synthesis, the susceptibility of the individual to various diseases.

Since maintaining the integrity of this master blueprint is so vital, the cell makes a 'photocopy' of the DNA called RNA, so that the risk of damaging the DNA is minimized. This photocopy blueprint is taken to 'construction sites' in the cell. These construction sites are called ribosomes. On these ribosomes, the RNA blueprint is used to direct the manufacture of proteins and enzymes, which, in turn, directly determine the structure, traits, and limiting capabilities of the body.

To further insure the integrity of DNA, the cell provides a group of enzymes called the DNA repair enzyme system which repairs DNA when damage is done to it. As people age, their DNA repair enzyme system slows down. This results in DNA damage which goes unrepaired and leads to cell damage or death. Damaged or dead cells may then put out products which in turn damage other cells, leading eventually to massive cell death and the degenerative loss of various tissues and organs in a snowballing cycle of aging > damage > aging .

Serious consequences can also arise if the unrepaired DNA damage occurs in a cell which gives rise to a sperm or egg cell. In these cases, DNA damage in the defective egg or sperm cell will be replicated in every cell of the offspring's body and will lead to a birth defect. If the child with this birth defect survives to maturity and reproduces, this genetic deformity will be passed on from generation to generation. A decline in DNA repair activity with 'age' is one of the reasons why the number of birth defects increases as maternal age increases.

Unrepaired damage of a segment of the DNA responsible for control of cell growth (brought about by a deficient DNA repair enzyme system) can lead to uncontrolled cell growth or tumors. Many tumors stop growing when they are contained by the cells around them. However, in some cases, tumor cells may release an enzyme, or may be induced by additional genetic damage to release an enzyme, which digests the surrounding cells. The result is an invasive or malignant tumor and is more commonly referred to as cancer.

An excellent example of a defective DNA repair enzyme system leading to cancer is provided by victims of a disease called xeroderma pigmentosum. These people suffer from an inherited deficiency of DNA repair enzyme activity and are known to succumb to cancer early in life as a result.

A decline in DNA repair activity with 'age' is one of the primary reasons why the incidence of cancer among older people is so much higher than the cancer incidence among younger people. The defective DNA repair enzyme in patients with xeroderma pigmentosum accelerates the aging process to the extent that xeroderma pigmentosum patients in their 20's have the same cancer risk as 'normal' people in their 80's.

Dr. Wolfgang Klein and co-workers at the Seibersdorf Research Center in Austria reported that 1 part per million fluoride inhibits DNA repair enzyme activity by 50%. Since fluoride inhibits DNA repair enzyme activity, fluoride should also be expected to lead to an increase in genetic or chromosome damage.

This has indeed been found to occur in numerous studies showing that fluoride in water, even at the concentration of 1 part per million, can cause chromosome damage.

The following table outlines the results of laboratory studies regarding the effect of fluoride on genetic damage in mammals.

*A prepublication copy of this paper was submitted as an exhibit in a court case in Pittsburgh (USA). During trial, it was brought out that the results showed that increasing fluoride contents in drinking water increased genetic damage in mouse testes cells. Before the paper was published these figures were altered so as to destroy the original figures showing a relation between fluoride and genetic damage (see Chapter 16).

One of the most relevant of these studies are those of Dr. Aly Mohamed, a geneticist at the University of Missouri. They show that one part per million fluoride in the drinking water of mice causes chromosomal damage. These studies also show that as the fluoride content of the water increases the degree of chromosomal damage increases in both testes and bone marrow. The results are presented in the following table:

(Click to enlarge table)
Chromosomes (and thus any chromosomal abnormalities that may occur) are only visible while the cell is dividing. Therefore, Dr. Mohamed studied bone marrow and testes cells since these cells divide rapidly.

Since the testes cells observed by Dr. Mohamed give rise to sperm cells which are passed on to future generations, genetic damage to these testes cells can lead to birth defects and other metabolic disorders which can be passed on from generation to generation.

Early studies regarding the ability of fluoride to cause chromosome damage were done on plants and insects and as a result drew little attention. However, since the basic structure, function, and repair of chromosomes is similar in plants, insects, and animals, substances like fluoride which cause genetic damage in plants and insects, will most likely cause genetic damage in animals-including man.

The following table outlines the results of laboratory studies regarding the effect of fluoride on genetic damage in plants and insects.
 

Drs. R.N. Mukherjee and F.H. Sobels from the University of Leiden in Holland found that fluoride increased the frequency of genetic damage in sperm cells which were produced by laboratory animals exposed to X-rays. It is evident, from their studies, that fluoride inhibited the repair of DNA damaged X-rays. The authors themselves concluded: 'sodium fluoride resulted in a consistent and highly significant increase of the mutation [i.e. genetic damage] frequency. This effect is thought to result from interference with a repair process.'

In agreement with Drs. Mukheijee and Sobels were Dr. S.I. Voroshilin and co-workers from the Russian Research Institute of Industrial Health and Occupational Diseases. From their studies they concluded: 'It would seem to us that fluoride could cause some kind of disturbance in the enzymes that are related to the mechanisms of DNA repair and synthesis.'

In 1981, Dr. A. Iarez and co-workers from the Department of Toxicology from Central University ofVenezuela in Caracas reported that fluoride added to the drinking water of female rats produced birth defects in their offspring. Just one year later Drs. Rhuitao Zhang and Shunguang Zhang of the Changjian Institute of Marine Products found that fluoride caused birth defects in fish.

According to the June 16, 1976 issue of the San Diego Union, an experiment showed that 10% of the litters of female mice drinking tap water from Durham, North Carolina (fluoridated in 1962) contained at least one malformed baby. No birth defects were observed in mice drinking purified water. While this study in itself does not prove that fluoride was the cause, the effects of fluoride as determined by the investigators mentioned above certainly make fluoride a prime suspect.

Fluoride-Induced Cancer

The ability of fluoride to cause genetic damage is so well recognized that investigators are now trying to find ways to counteract its genetic damaging effects.

Substances like fluoride which cause genetic damage are called mutagenic substances and it is a well-accepted fact that substances which are mutagenic also tend to be carcinogenic, or cancer producing. In fact, this is exactly what has been found with regard to fluoride.

Dr. Takeki Tsutsui and co-workers of the Nippon Dental College in Japan showed that fluoride not only caused genetic damage but was also capable of transforming normal cells into cancer cells. The levels of fluoride used in this study were the same levels of fluoride that the U.S. National Cancer Institute suggested should be used to determine whether or not fluoridation of public water supplies causes cancer.

They found that cells treated with 34 and 45 parts per million fluoride produced cancer (fibrosarcoma) when injected under the skin of otherwise healthy adult hamsters. In contrast, they found that cells that were not treated with fluoride did not produce cancer.

This confirms the earlier U.S. National Cancer Institute sponsored studies done by Drs. Irwin Herskowitz and Isabel Norton. In 1963, these St. Louis University scientists showed that low levels of fluoride increased the incidence of melanotic tumors in fruit flies by 12 to 100% (see the following figure).

(Click here to enlarge)

Similar types of transformations of normal cells to potentially cancerous cells have been observed in humans.

Dr. Danuta Jachimczak and co-workers from the Pomeranian Medical Academy in Poland reported that as little as 0.6 part per million fluoride produces chromosomal damage in human white blood cells. This study has received support from two other studies by Dr. R. Lin and co-workers from the Kumming Institute of Zoology and Dr. E.J. Thomson and co-workers from the Medical Research Council in Edinburgh, Scotland, who showed a 2-fold to 15-fold increase in chromosomal aberration rates at levels of 1.5 to 60 parts per million fluoride. The Thomson study suffers from the fact that the investigators administered another mutagenic substance to all the cells tested to measure other indexes of chromosomal activity.

Dr. Stephen Greenberg from the Chicago Medical School observed a disturbance of the DNA in white blood cells of animals treated with 5-10 ppm fluoride and observed other changes which he maintained were characteristic of cancer cells. In humans, Dr. Paul H. Duffey and co-workers from the Tucson Medical Center also found that fluoride transforms certain white blood cells into cells which appeared to be cancerous.

It is quite clear that fluoride causes genetic damage. The mechanism of action of fluoride cannot be exactly pinpointed because fluoride interferes with a number of physiological processes. Most evidence indicates that fluoride acts on the DNA repair enzyme system. This does not rule out the possibility that fluoride also interferes with DNA synthesis or that it may even act directly on the DNA itself. DNA is composed of two molecular strands held together by hydrogen bonds and fluoride is capable of disrupting these bonds. Such disruption would be expected to result in genetic damage directly and/or interference with DNA synthesis and DNA repair.

Furthermore, fluoride-induced genetic damage may also result from the general metabolic imbalance caused by fluoride selectively inhibiting certain enzymes.

The fact that fluoride has also been shown to cause cancer should not be surprising since it is almost universally accepted that cancer results from genetic damage.

In any event, the fact that fluoride disrupts DNA repair enzyme activity, the fact that fluoride causes genetic damage, and the fact that fluoride causes cancer shows again that fluoride is directly accelerating the aging process.