Fluorine is a toxic, highly reactive gas from the halogen group. The chemical element does not occur in nature in elemental form, but only in bound form – and that is when fluorine chemically combines with a mineral. This is how calcium or sodium fluoride is formed, for example. The trace element fluoride is most likely not essential for humans and is mostly stored in the teeth and bones. Fluoride is ingested in small amounts through food and is often added to toothpaste, table salt or mineral water to prevent tooth decay. However, these measures are controversial – wrongly?
Fluoride in food
Fluoride is in relatively few foods, and if it is, it is in low concentrations. These include seafood, nuts, black tea, meat and soy products. In addition, fluoride is present in small amounts in tap and mineral water – in Germany, drinking water often contains less than 0.3 milligrams per liter. In fluoride-poor areas in the U.S., Canada and Great Britain, extra fluoride is sometimes added to tap water to prevent deficiencies in the population. According to the German Nutrition Society (DGE), the recommended daily intake of fluoride is between 0.25 and 3.8 milligrams, depending on age and gender. Two milligrams of fluoride are contained, for example, in:
- 379 g pork liver
- 405 g plaice
- 2 kg muscle meat
- 1.24 kg shrimp
- 1.5 kg butter
- 10 kg vegetables
Fluoride in the body
Fluoride is responsible in the human body for strengthening the bone structure and hardening the enamel. As a result, fluoride protects teeth from environmental factors and acids, and thus from tooth decay. 95 percent of the fluoride in the body is stored in the teeth and bones – the rest is in the hair, nails and skin. Especially during pregnancy, doctors often advise an increased intake of fluoride, since the baby needs fluoride to form bones and teeth. However, studies suggest that fluoride may adversely affect the baby’s brain development and intelligence. Evidence of neurotoxicity from fluoride has existed for some time.
Fluoride Deficiency
Some doctors and scientists warn that fluoride deficiency can lead to tooth decay, osteoporosis, and hardening of the arteries and therefore recommend fluoride-containing mineral water, toothpaste, and fluoride tablets. Others do not think this is necessary, since fluoride is already absorbed in a normal diet through drinking water and food, and this amount is sometimes considered sufficient. Finally, fluoride is not essential and fluoride overdose is much more dangerous than fluoride deficiency.
Overdose: acute fluorosis
A one-time dose of five milligrams of fluoride per kilogram of body weight is reported as a likely toxic dose. As a result, so-called acute fluorosis may occur. Symptoms of such fluoride poisoning include:
- Nausea
- Vomiting
- Diarrhea
- Abdominal pain
- Seizures
- Paresthesia (sensory disturbances, for example, tingling or numbness).
Fluoridated table salt contains 0.25 milligrams of fluoride per gram. With an average consumption of 2 grams of salt per day, you thus take 0.5 milligrams of fluoride alone about it. Anyone who uses fluoride salt in the home or whose water contains more than 0.7 milligrams of fluoride per liter should not additionally reach for fluoride tablets to prevent an overdose.
Chronic fluorosis as a result of long-term overdose
If one ingests 10 to 20 milligrams of fluoride daily for several years, there is a risk of chronic fluorosis. This paradoxically leads to a softening and structural change of the tooth enamel (dental fluorosis), which is accompanied by a stained coloration of the teeth. Other symptoms include:
- Cough
- Sputum
- Shortness of breath
Tooth stains are particularly common in the first eight years of life, when teeth are developing the most. Therefore, the recommendation is: as little fluoride as possible for babies and children. Chronic fluoride poisoning can also lead to bone thickening and joint stiffness (fluorosteopathy). Muscle and kidney function disorders can also occur from fluoride overdose.
Fluoride under criticism
Opinions about fluoride vary widely.While some doctors and scientists consider fluoride important and advise adding it to food, critics warn against “forced fluoridation” of the population. The fact is that fluoride in moderation is important for the human body. However, there is disagreement about whether additional administration of fluoride via toothpaste, table salt or mineral water is necessary. Healthy people with a balanced diet do not usually need additional fluoride and can therefore do without fluoride salt and the like. However, products such as fluoride toothpaste can help people with low tooth enamel or exposed tooth necks – these products are generally considered to be recommendable. Numerous studies have demonstrated the positive effect of fluoride in strengthening tooth enamel and preventing tooth decay. An overdose is completely impossible with normal use of toothpaste – for that you would have to eat several tubes of toothpaste a day. However, one should not confuse the relatively harmless fluoride with the gas fluorine, which is actually toxic.
