Fluoride Fact on Human Health and Health Problems: A Review

Abstract

Fluorine (F -) is a chemically reactive electronegative univalent gaseous halogen found in small amount in the water, air, plants and animals. Fluorine is essential for the maintenance and solidification of our bones and to prevent dental decay. It has beneficial effects on teeth and bones when it is present at low concentration in drinking water, but excessive exposure to fluoride in drinking-water, or in combination with exposure to fluoride from other sources, can give rise to a number of adverse effects which include teeth decay, osteoporosis and harm to kidney, bones, reproductive organs, nerve and muscle. Fluoride, when in excess, is known to interfere with thyroid gland function causing TSH elevation and lessen T3/T4 hormones in some populations which may be due to its antagonistic properties towards iodine. As an endocrine disruptor, Finduces more toxic outcome in diabetic patients. Chronic Fexposure through drinking water may leads to insulin resistance in humans in addition to its hyperglycemic effect due to increased hepatic glycogenolysis. Fluoride also hinders glycolysis by inhibiting enolase enzyme and repressing insulin secretion from islets of Langerhans cells resulting in elevation of blood glucose level. High Fexposure is also associated with increased levels of FSH and LH, decreased estrogen and testosterone levels, disturbed androgen to estrogen ratios (A/E) and estrogen receptor to androgen receptor ratios (ER/AR). Decreased circulating testosterone concentrations were also reported in male skeletal fluorosis patients. The most significant consequences of fluoride exposures in male reproduction are: changes in the structure and functional activities of spermatozoa and disruption of spermatogenesis while in an experimental data involving female rats showed that high fluoride concentration lowers the pregnancy rate and the number of implantation. Most interestingly, recent research showed that exposure to high concentration of Fdoes have deleterious effect on the mental ability of children. A strong association between exposure to fluoride and low IQ was found and it was also noted that children who live in fluorosis prevalent areas have higher chances of developing a low IQ than those who live in normal areas. So it is clear that the severity of the above pathological conditions is dependent on the dose, duration and age of the individual. Therefore, to ensure whether people need any fluoride supplements or not, government should have to take initiative to prevent health problems due to deficiency or excess fluoride exposure. Evidence-wise further thorough research is essential based on scientific facts to enlighten best practices in the use of fluoride containing materials for the safety and security of public health.

Correlation between drinking water fluoride and TSH hormone by ANNs and ANFIS

“…As mentioned by Basha et al (2011) and Dey and Giri (2016), fluoride can block the iodine receptors in the thyroid gland therefore, we are suggest a study can be done on using pure treated drinking water by hypothyroidism when they are treated by medication. The thyroid gland is the most sensitive tissue in the body to fluoride [2].…”

“…It has beneficial effects on teeth and bones at low concentrations but excessive exposure to fluoride has adverse effects [1][2][3][4][5][6][7][8][9][10]. There are ways to get fluoride, but water is the most important [11][12][13][14].…”

“…Iran's recommended level of fluoride in drinking water is 0.5-1.5 8 mg/L based on WHO Guidelines for drinking-water quality [19]. Dey and Giri (2016) found that excessive exposure to fluoride caused increase thyroid-stimulating hormone (TSH) and increase T 3 and T 4 hormones especially in people who do not consume enough iodine, therefore causing hypothyroidism [2]. They illustrated that consuming 20 mg/L sodium fluoride per day by rats repressed the production of nucleic acids and Triiodothyronine (T 3 ), thyroxin (T 4 ) hormones and change the activities of some metabolic enzyme such as: K (+) -Na (+) -ATPase, thyroid peroxidase, and 5, 5′-deiodinase [2].…”

“…Dey and Giri (2016) found that excessive exposure to fluoride caused increase thyroid-stimulating hormone (TSH) and increase T 3 and T 4 hormones especially in people who do not consume enough iodine, therefore causing hypothyroidism [2]. They illustrated that consuming 20 mg/L sodium fluoride per day by rats repressed the production of nucleic acids and Triiodothyronine (T 3 ), thyroxin (T 4 ) hormones and change the activities of some metabolic enzyme such as: K (+) -Na (+) -ATPase, thyroid peroxidase, and 5, 5′-deiodinase [2]. Rastogi and Monika (2014) said that T 3 and T 4 are two hormones significant for the production of proteins to adjust body temperature which generates total energy, regulate the thyroid gland and controls human body metabolism [20].…”

“…Diagnosis of thyroid disease carried out by blood tests include the TSH, T 4 test [22,23,27]. Governments are responsible for researching on the health challenges of its people due to reduced or excessive fluoride exposure [2]. Nowadays, computer technology and information have been developed in the sciences [28].…”