Fluoride water Information, danger, risks, poisoning, Fluorosis, can excess cause an underactive thyroid?
August 25 2017 by
Ray Sahelian, M.D.

Fluoride is a mineral in drinking water. In the United States fluoride is deliberately added to drinking water to strengthen teeth. But can this fluoride in drinking water be excessive and lead to damage to bones and teeth? Hundreds of thousands of people in the United States may consume water that is at or above the government's standard because of naturally occurring fluoride. Children exposed to the government's current maximum fluoride limit risk developing severe tooth enamel fluorosis, a condition characterized by discoloration, enamel loss and pitting of the teeth. The EPA allows up to 4 milligrams of fluoride per liter of drinking water.

The U.S. government has decreased its recommended level of fluoride in drinking water for the first time in a half-century, to prevent staining of tooth enamel caused by overexposure to fluoride. The optimal fluoride level in drinking water to prevent tooth decay should be 0.7 milligrams per liter of water, the U.S. Department of Health and Human Services (HHS) announced in April 2015. The new level falls at the bottom end of the previously recommended fluoridation range of 0.7 to 1.2 milligrams per liter, which was issued in 1962.

Natural protection
Indian J Exp Biol. 2016. Protective role of diet supplements Spirulina and Tamarind fruit pulp on kidney in sodium fluoride exposed Swiss albino mice: Histological and biochemical indices. Fluoride toxicity through potable water, particularly ground water, is not uncommon in countries such as India, China, Iran, Iraq, Turkey, parts of Africa and Afghanistan. Kidney being the main organ involved in fluoride removal, it accumulates considerable amount of fluoride. Here, we report toxic effects of oral exposure of Swiss albino mice to fluoride (sub-acute: 190 mg/kg body wt. for 7 days; and sub-chronic: 94 mg/kg body wt. for 90 days) and recovery of sub-chronic fluoride exposed mice after 90 days of sodium fluoride (NaF) withdrawal. The role of diet supplements (Spirulina and tamarind fruit pulp @ 230 mg/kg body wt. independently as well as in combination) in amelioration of fluoride toxicity has also been screened. The diet modulation not only reduced fluoride toxicity but also led to better recovery of treated mice after withdrawal, especially in combination.

Fluoride danger
There has been some mention that tea, such as black or green tea, has a high concentration of fluoride and could be harmful if drank too much. I am still awaiting results of more studies to determine whether drinking too much tea can be harmful in terms of this mineral toxicity.

A 2015 British study finds a correlation between the amount of fluoride in public drinking water and a rise in incidence of underactive thyroid.

Rodent studies show excess fluoride in the water leads to oxidative stress, DNA damage and apoptosis. Perhaps very high intake can interfere with proper mental functioning. The danger can be reduced by using less toothpaste with this mineral.
   U.S. government officials said in 2011 that the amount of fluoride in the nation's drinking water should now be set at the lowest recommended level. Although it is a significant help in preventing cavities and tooth decay, too much of it can cause unattractive spotting on children's teeth. About two out of five teens have white spots and streaks on their teeth due to excess intake. To prevent this problem, the U.S. Department of Health and Human Services and the U.S. Environmental Protection Agency are recommending that the fluoride level in drinking water be set at 0.7 milligrams per liter of water, replacing the current recommended range of 0.7 to 1.2 milligrams.

Toxicol Lett. 2013 Nov 25. A brief review on experimental fluorosis. Fluoride (F) is a naturally occurring contaminant in the water. F is essential for normal maintenance of teeth and bones. However, prolonged exposure to high concentration of F is found to be deleterious to teeth, bones and other organs. Besides drinking water, F can enter the body through food, dental products, drugs and industrial emission. People living in areas where F contamination is much higher than the expected level, are found to suffer from not only teeth and bone problem but also other systems, including brain and its functions. Since animals respond to the toxic effects of F like human beings, the deleterious effects of F have been produced experimentally in animals in order to determine the mechanism involved in the action of F. The reports indicating the chronic harmful effects of F in teeth, bones, heart, liver, kidneys, gastrointestinal tract, lungs, brain, blood, hormones and biochemical parameters of experimental animals and in in vitro studies have been reviewed in this article. The neurotoxic action of F that produces chiefly learning and memory impairment has also been included. The review also points out the harmful effects of F on reproduction, its teratogenic action and in inducing premature ageing. Finally, the reports indicating a reversal of certain toxicities of F in experimental animals after withdrawal of its exposure has been included.

Environ Health Perspect. 2012. Developmental fluoride neurotoxicity: a systematic review and meta-analysis. Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA.  The results support the possibility of an adverse effect of high fluoride exposure on children's neurodevelopment.

Fluoride Can Damage the Brain – Avoid Use in Children
"The prolonged ingestion of fluoride may cause significant damage to health and particularly to the nervous system," concludes a review of studies by researchers Valdez-Jimenez, et al. published in Neurologia (June 2011), reports New York State Coalition Opposed to Fluoridation, Inc. (NYSCOF).The research team reports, “It is important to be aware of this serious problem and avoid the use of toothpaste and items that contain fluoride, particularly in children as they are more susceptible to the toxic effects of fluoride” (1)“Fluoride can be toxic by ingesting one part per million (ppm), and the effects are not immediate, as they can take 20 years or more to become evident,” they write.

Fluoride Toothpaste information
Fluoride toothpastes may be a risk factor in dental fluorosis. There is a debate in the scientific community regarding its appropriate use in toothpaste in order to maximize the benefit and minimise the risk of excess exposure. Three factors have an important influence on the anticaries efficacy of fluoride toothpaste, namely concentration, frequency of brushing and post brushing rinsing behavior. The evidence suggests that low-fluoride (<600 ppm F) toothpastes provide less caries protection than standard (1,000 ppm F) or high (1,500 ppm F) concentration formulations. However, low-fluoride toothpastes are appropriate for very young children (under 7 years) at low caries risk, particularly if living in fluoridated areas. For other young children, a standard concentrations of fluoride could be used except in communities where the water supply has adequate amounts of fluoride. Small amounts of toothpaste are comparable in efficacy to large amounts. The risk of fluorosis is associated with the ingestion of high doses of fluoride during tooth development and consequently mostly young children are at risk. The variability in the dose of fluoride ingested is mainly a function of the amount used, less so its concentration. To minimize fluorosis risk, parents should be advised to use only a pea-sized amount of toothpaste and encourage spitting out of excess. It is concluded that by using fluoride toothpastes appropriately, the benefits can be maximised and the risks of fluorosis minimised. However, since there is concern that some communities may have more fluoride in their water than necessary, it may be a cautious approach for the time being to use low fluoride toothpastes until more information is gathered.

Fluoride from salt (sodium fluoride) or fluoride in water is absorbed from the stomach and intestines. Because fluoridated salt is almost always ingested with food, absorption from the gastrointestinal tract may be delayed or reduced and, therefore, peak plasma concentrations are lower than when fluoride is ingested with water. The amount of ingested fluoride that is finally absorbed, however, is not appreciably affected unless the meal is composed mainly of components with high calcium concentrations. In this case, the extent of fluoride absorption can be reduced by as much as 50%. Fluoridated salt is ingested less frequently than fluoridated water.

Am J Dent. 2014. Fluoride content in breast milk after the use of fluoridated food supplement. A randomized clinical trial. To evaluate if the intake of a fluoridated food supplement in breastfeeding mothers increases the fluoride concentration in breast milk. A double-blind randomized placebo-controlled study was designed. Two groups of women were formed: a fluoride group (n = 112), using a non-sucrose food supplement containing fluoride (1,500 μg/l for each dose) and a control group (n = 116), using a non-sucrose food supplement without fluoride content. The women were followed for 6 weeks. Samples of breast milk were collected and analyzed using an ion-specific electrode. Fluoride concentrations in the two groups were statistically significantly different (515 μg/l in the fluoride and 476 μg/l in the control group) at the end of the experimental period. In the fluoride group, a statistically significant increment in fluoride concentration during the experimental period was also observed (from 468 ± 104 μg/l to 515 ± 105 μg/l). The use of a non-sucrose food supplement containing fluoride resulted in a significant increment in fluoride concentration in breast milk.

Measuring fluoride level
Fingernail fluoride concentrations reflect fluoride exposures from drinking water, toothpaste and the work environment.

Influence on thyroid gland
I read that fluoride is very bad for people with hypothyroidism, but have yet to read it from an actual doctor or health professional.
   A. I have not come across convincing studies that normal fluoride ingestion through water or food has a strong influence on thyroid function. It is possible that industrial workers exposed to excessive amounts could have problems with the thyroid gland.

Fluorine and thyroid gland function: a review of the literature.
Klin Wochenschr. 1984.
The increasing use of fluoride for prevention of dental caries poses the problem as to whether this halogen has antagonistic properties towards iodine, whereby it could hamper the success of iodine prophylaxis of endemic goitre. Review of the literature shows that some authors have found an inhibition by fluoride of various steps of thyroid hormone biosynthesis in animal experiments. By and large, the inhibition was only slight and it was elicited only with fluoride doses greatly in excess of those recommended for caries prevention. The inhibition was not consistently present and other authors could not confirm it in comparable experiments. There is no convincing evidence that fluoride produces true goitres with epithelial hyperplasia in experimental animals. There are some reports based on casual observations that fluoride is goitrogenic in man. On the other hand, several good studies with adequate exposed and control populations failed to detect any goitrogenic effect of fluoride in man. It is noteworthy in particular that fluoride does not potentiate the consequences of iodine deficiency in populations with a borderline or low iodine intake. Published data failed to support the view that fluoride, in doses recommended for caries prevention, adversely affects the thyroid.

Amount in tea
Dear Dr. Sahelian, please refer to the following website. I have been studying about the detrimental effects of fluoride in our water and other sources of fluoride contamination. It turns out tea just naturally absorbs fluoride, especially green tea. So despite its various health benefits, there are apparently some serious drawbacks as well. It will be very hard for me to accept advice to drink it without the possibility of contamination by this poison. I don’t know if you are aware of this situation or not. I hope this helps you to understand more of what we are constantly up against in our food supplies. This article comes from a man trying to sell his brand of tea, claiming it is lower in fluoride because of the way it is processed. http://www.foodnavigator-usa.com/news/ng.asp?id=58604-calls-for-fda I hope this will enlighten you and your staff to this situation. Imagine a well meaning consumer hoping to improve his/her health only to be adding to their problems. What about athletes and construction workers drinking huge amounts of water with toxic fluoride in it and then drinking green tea or other teas with huge additional amounts of fluoride in it? It is no wonder why we have osteoporosis and hypothyroidism at escalating levels in this country. Thank you for all you do to help your readers navigate the world of nutrition and supplements. I have been reading your newsletters and ordering products formulated by you for several years now. You are a breath of fresh air.
   Thank you for the positive feedback. Some studies have shown that drinking tea has health promoting potential. I think we have to look at the final result (health promotion with drinking tea) rather than analyze every single mineral or substance in a food or drink. Japanese have been drinking green tea for a long time, and if it is true that it has a high fluoride level, apparently it is not affecting their longevity. I also believe in alternating a variety of teas and not just drink the same one from the same company all the time. I have at least a dozen different herbal teas on my kitchen counter. I also think it is important to ingest a variety of fluids, not just tea. For instance coffee, vegetable juices, diluted fruit juices, etc. But, thanks for bringing the connection of fluoride and green tea to our attention, we will keep a close eye on what additional studies indicate.

Fluoride content in tea and its relationship with tea quality.
J Agric Food Chem. 2004.
The tea plant is known as a fluorine accumulator. Fluoride content in fresh leaves collected from 14 plantations in China was investigated. The fluoride increased with maturity, and the fluoride variation was remarkable in the tender shoots. Furthermore, significant negative relationships were observed between fluoride content and the content of the quality parameters total polyphenols and amino acids. These substances are rich in young leaves and poor in mature ones. With regard to quality of tea products, the relationship with fluoride content was studied using 12 brands of tea products in four categories: green tea, oolong tea, black tea, and jasmine tea collected from six provinces. The fluoride level increased with the decline in quality and showed good correlation with the quality grades. The results suggest that the fluoride content could be used as a quality indicator for tea evaluation.

Q. I have a PhD in Chemistry w/specialization in Biological Chemistry, I am University-trained specialist in Industrial Hygiene. I have studied Computer Sciences as well as Electronic Engineering. I have worked in the Pharmaceutical industry for over 20 years now, and have access to the latest research. I am not a crackpot. One of the compounds that needs to be taken very seriously is Fluoride. Sure, there are plenty of other contaminants (heavy metals, about 10.000 new organic chemical compounds released into the environment per year, etc.). However, Fluoride is the one that can be very easily controlled in tea. Furthermore, tea extracts may or may not further concentrate fluoride depending of the chemical process itself. There are tons of fluoride research papers showing that, without actually reaching the toxic levels where fluorosis symptoms will show, fluoride produces basically two events: cancer and lower IQ. The most worrying part is that fluoride can do that with extremely low doses, such as the ones considered "safe" for drinking water. Please note that in nature, there are NO fluoride-rich wild vegetables / vegetation or sources of water. Why? Simply because Fluoride is too electronegative and, chemically speaking, will bind very forcefully with just about any molecule... which is exactly what gives fluoride its capacity to trigger cancer and play havoc with metabolisms. Anecdotal evidence: if you take a look at the chemical history of fluoride compounds you will notice that ALL the early researchers (between the 50's and late 70's) are ALL dead. NO exceptions. And, they all died in their 40's and 50's top. Fluoride is really nasty. More anecdotal evidence: almost all EU nations have banned water fluorination. They have seen the data. Want more? the fluoride used for fluorination over here is actually waste product from Aluminum processing plants. And this is here, in the so-called "developed" world. Can you imagine what is like in... say China? For example, drinking "average" green tea (from China, for example), one teabag a day (in 250 ml tap water) would produce an intake of about 3 to 4 times the "safe" level of fluoride. This is, the equivalent of drinking a whole liter of tap water. This is worrying. A further example. I have contacted several manufacturer's of green tea extracts, and received answers varying anywhere between "we don't care" to "yes, our product is extremely low in Fluoride and where may we send you the third party Certificate of Analysis to prove it". I believe people should at least request Green Tea extract manufacturers ensure low Fluoride levels, because said levels are much more easily controlled during extraction than trying to alter watering practices on growers.
   A. Excess fluoride exposure is a risk to consider. However, studies in Asia link green tea consumption to longevity. I am not concerned about drinking green tea a few times a week or a few times a month. If one analyzes in detail all the foods we eat, there is always something to worry about in just about every food. It's best not to worry excessively. The worry alone is more likely to be harmful to the body and mind than the actual minor toxins or other substances in the foods we eat or teas we drink.

Questions and emails
Q. I was shocked when I recently learned that the chemicals used to fluoridate most of America' s water supply were never approved by the FDA as fit for human consumption. They are industrial grade waste products - fluorosilicate compounds. Fluoride is a potent toxin ranging between lead and arsenic in acute toxicity. Exposure is excessive as it is found in food (pesticide residue), beverages made with fluoridated water, also in wine and tea in addition to dental products. New studies have linked it with serious health concerns - The publication in 2006 of a 500-page review of fluoride toxicology by a distinguished panel appointed by the National Research Council - (part of the US National Academy of Sciences) lists them: bone fractures, decreased thyroid function, impaired glucose tolerance, brain cell damage, lowered IQ, kidney damage, arthritic-like conditions, symptoms characteristic of Alzheimer's disease and cancer. Isn't it about time the American people learn what's in their water and why it shouldn't be?
   A. I have not studied the fluoride problem in enough detail to have a well thought out opinion at this time.

There is a company that sells a tincture of tamarind herb. What are your thoughts on tamarind as a detox for too much fluoride.
   I have come across one human research regarding the use of tamarind herb and its effect on fluoride levels in the body.

What is your opinion on fluoride? Is it really good for the teeth or is it being used to dumb down people?
   It's hard to say for sure and it is a controversial topic, but my best guess is that it would be fine if the public consumed less of it than it is at the present time.