What is fluoride?
Fluoride is a mineral that occurs naturally and is released from rocks into the soil, water and air. According to the Drinking Water Inspectorate, it occurs most often in groundwater.
Most people are exposed to fluoride due to the fact that it is added to dental care products, such as toothpastes and mouthwashes. These products should be spat out, after cleaning one’s teeth. However, fluoride can also be present in some drinks made from fluoridated water (e.g. fruit juices and soft drinks) and will therefore be ingested.
Fluoride helps to remineralise tooth surfaces and prevent cavities from forming, so small amounts of fluoride do help improve dental health. However, ingesting more fluoride than the recommended limit leads to toxicity and adverse effects.
Despite fluoride being commonly found in oral care products with the aim of improving oral health, it may also be added to tap water for the same reason (water with added fluoride is called fluoridated water). However, the amount of fluoride in your own water supply will vary according to your region’s geology and depending on whether additional water fluoridation has taken place.
Over-exposure to fluoride when the body is growing and developing can lead to dental fluorosis. In mild cases, this means white flecks on the teeth. In severe cases, teeth can appear brown and corroded. A 2018 Public Health England report found that that this condition was more prevalent in 11- to 14-year-olds in Newcastle and Birmingham (fluoridated cities) than in Manchester and Liverpool (non-fluoridated cities).
Other reports have pointed to more severe effects. Fluoride has been linked with a lower IQ in young children whose mothers were exposed to higher levels of fluoride during pregnancy, to a higher risk in developing a rare bone cancer among teenagers, and to people suffering from an underactive thyroid (hypothyroidism), where the thyroid gland does not produce enough hormones to regulate the body properly, which in turn can lead to other health issues.
A Chinese study has also drawn a link between fluoridated water and evidence of kidney (and possible evidence of liver) damage.
Fluoride damages nerve tissue and disrupts the body’s hormones. It can harm the thyroid gland and calcify the pineal gland in the brain which is believed to help regulate the body’s sleeping and waking cycles and other reproductive hormones.
According to the Drinking Water Inspectorate, some water companies are required by the local health authority to fluoridate water supplies to protect against tooth decay. It adds that fluoridating water is a Department of Health policy.
The allowable limit for fluoride in UK drinking water is 1.5 milligrams per litre.