What is fluoride – and why is it used?

Fluoride (fluoride ion) is a mineral that binds to tooth enamel and makes it more resistant to acid attacks. Therefore, fluoride has become an almost natural part of toothpaste, mouthwash, and preventive dental care.

When does fluoride become a problem for the body?

The body has no active mechanism to “turn off” fluoride. Some is excreted via the kidneys, but some is stored in teeth and skeleton over time. In children, with low body weight and immature detoxification, the same amount of toothpaste can cause a much higher burden than in an adult.

Over time, excessive fluoride exposure can be linked to:

• Dental fluorosis – white spots, streaked or discolored enamel in children exposed to too much fluoride while teeth are forming.
• Skeletal fluorosis (with long-term, high exposure) – stiffer joints and changes in the skeleton.
• Possible impact on thyroid and hormones at high levels, as fluoride can compete with iodine in the body.
• Concerns about neurological development in studies showing a link between high fluoride in drinking water and reduced cognitive function in children.

Research is complex, and results vary. However, several recent reviews point out that we should consider total burden – especially in pregnant women and children – because the brain is especially vulnerable during developmental phases.

Where does our fluoride exposure come from today?

Many think of fluoride as something found only in toothpaste. In practice, the daily load can come from several invisible sources – also from products we would never associate with dental health.

When several of these sources combine, it is not hard to see how total exposure can become higher than we intuitively think – especially for small bodies that do not have the same capacity to handle the burden.

• Children who swallow toothpaste daily and use the same amount as adults.
• Combination of fluoride toothpaste, daily mouthwash, and regular fluoride rinses at school.
• Families in areas with naturally fluoride-rich drinking water who also use many fluoride products.
• Visible white spots, stripes, or discoloration on children's teeth (suspected dental fluorosis).
• High daily intake of strong tea (black/green) and drinks made with fluoride-containing water.
• Frequent use of non-stick pans with clearly worn or flaking coating.

Common misconceptions about fluoride

• “The more fluoride, the stronger the teeth.”
  The effect plateaus – and beyond a certain level, it is no longer about dental health, but about the risk of fluorosis and burden on the body.
• “Fluoride only works locally in the mouth.”
  Fluoride that is swallowed is absorbed into the blood and stored in teeth and skeleton, and can affect other organs at high levels.
• “Children tolerate fluoride as well as adults.”
  Children have lower body weight, immature kidneys, and more often swallow toothpaste – resulting in a higher relative dose.
• “Natural fluoride is harmless.”
  The body does not distinguish between “natural” and “added” fluoride. Dose and duration are decisive.

Who is most vulnerable to fluoride exposure?

All age groups can be affected by long-term high fluoride burden, but some phases are especially sensitive.

• Infants and toddlers (0–3 years)
• Preschool and early school children (3–8 years)
• Children with high tea, soda, or juice intake
• People with reduced kidney function
• Areas with fluoride-rich drinking water

In small children, the time when permanent teeth are forming is critical. Too much fluoride during this period can cause lasting aesthetic changes (fluorosis) that follow them into adulthood – long after the “prevention” was actually necessary.

Fluoride, concentration, and the child's brain

In recent years, several research groups have examined the link between fluoride burden and children's cognitive development. The findings are not conclusive, but a recurring theme is that high, long-term exposure can be linked to small but measurable differences in:

• concentration and attention
• working memory and learning
• reaction time and information processing
• regulation of restlessness and sleep

This does not mean that fluoride alone “explains” neurodevelopmental challenges. But it means that fluoride is part of the total environmental burden on the brain – alongside heavy metals, endocrine disruptors, and nutritional deficiencies.

Many parents of children with concentration difficulties, restlessness, learning difficulties, or sensory challenges (including children on the autism spectrum) describe a complex picture of diet, sleep, environmental toxins, and gut health. Fluoride is one of the factors it may be sensible to monitor when aiming to reduce unnecessary burden on a vulnerable nervous system.

Common everyday situations

You might recognize one or more of these:

• Your child loves brushing teeth and eats the toothpaste because it tastes sweet.
• The whole family uses the same strong fluoride toothpaste – including the two-year-old.
• The child receives extra fluoride rinses at school or at the dental hygienist “just to be safe.”
• You drink a lot of black or green tea during the day.
• The family lives in an area where the water is naturally mineral-rich, without knowing the fluoride content.
• The kitchen is full of non-stick pans and molds that have been used for many years and are starting to flake.

Fluoride, aluminum, and the brain – why the combination draws attention

Another metal often mentioned in brain discussions is aluminum. We can be exposed to aluminum through cookware and baking molds, aluminum foil, certain food additives, cosmetics, and the environment.

Fluoride and aluminum can form complexes in the body (for example aluminum–fluoride complexes). Animal studies show that:

• combined exposure can affect the hippocampus – the brain area important for learning and memory
• there can be more oxidative stress and changes in nerve cell structure than with exposure to fluoride or aluminum alone
• some changes resemble those seen in other neurodegenerative processes

We do not yet have all the answers from human studies, but the precautionary principle suggests it is wise to avoid unnecessarily high levels of both fluoride and aluminum – especially during periods when the child's brain is developing rapidly.

In practice, this means for many families:

• limiting use of heavily worn non-stick and aluminum cookware, especially for acidic foods
• being aware of toothpaste, water quality, and other fluoride sources simultaneously
• choosing solutions that reduce exposure where it is easy to make good choices – without unnecessary fear.

What can you do to reduce unnecessary fluoride burden?

• 1 Get an overview of total exposure.
  Look at how often you brush teeth, whether children swallow toothpaste, if you use mouthwash/fluoride rinses, how much tea is consumed, what pans you use, and what kind of water you have.
• 2 Adjust toothpaste to the child's age.
  For small children, a rice grain or pea-sized amount is enough. Teach them to spit out, and avoid making toothbrushing a “dessert.”
• 3 Avoid layering fluoride on fluoride.
  Avoid simultaneous use of strong fluoride toothpaste, daily fluoride rinses, and frequent fluoride treatments if caries risk is low. Prevention should be targeted, not automatic.
• 4 Check and filter drinking water.
  Check the fluoride content in municipal water where you live – especially if you also use many fluoride-containing products and drink a lot of tea. At high levels, filters like reverse osmosis or specific fluoride filters can help reduce the burden.
• 5 Look at cookware and baking equipment.
  Replace old, flaking non-stick pans and molds. Consider more stable alternatives like cast iron, stainless steel, or high-quality ceramic coatings.
• 6 Strengthen teeth naturally.
  A diet low in sugar, regular meals, plenty of minerals (calcium, magnesium, phosphorus, vitamin D and K2), and good saliva production give strong teeth – even without maximum fluoride burden.
• 7 Talk to your dentist/doctor – with the whole picture on the table.
  Share information about water quality, tea consumption, diet, use of non-stick pans, and existing fluoride use. Ask for recommendations that consider both dental health and bodily burden.

Summary

Fluoride is neither the hero nor the villain alone. It is a tool – with an effect profile that requires respect for dose, duration, and vulnerable groups.

In a world where exposure can come from toothpaste, mouthwash, drinking water, tea, processed drinks, non-stick pans, cosmetics, and preventive treatments, it becomes important to see the whole picture. Especially for children, where small adjustments in daily life can make a big difference over time.

The most important thing is not whether you choose to reduce fluoride through toothpaste, drinking habits, cookware, or treatments – but that you know where it comes from, what it does in the body, and that you make informed choices for yourself and your family.