Does Fluoride Damage Your Brain Function?

Linked to reduced IQ and ADHD in children

According to the Fluoride Action Network (FAN), fluoride is the new lead – a poisonous substance that is linked to brain damage and lowered IQ, especially in children.

So, why is it added to water supplies and dental products?

This question has been raised numerous times. The safety of fluoride has been a topic of ongoing discussion and debate, raising concerns about potential risks despite assurances of its safety.

Uncover the hidden sources of fluoride, its potential health risks, and how to minimise your fluoride exposure.

What is fluoride?

There are different forms of fluoride: a naturally occurring type of fluoride called calcium fluoride, found in soil and groundwater, and synthetic industrial forms of fluoride, commonly known as sodium fluoride or fluorosilicic acid. These synthetic variants of fluoride are derived from industrial waste produced by fertiliser manufacturing and the aluminium industry. They are highly toxic. It is alarming that despite their toxicity, these synthetic fluoride compounds are used in public water supplies and toothpastes.

Facts about fluoride

Countries with water fluoridation do not exhibit lower rates of tooth decay compared to non-fluoridated countries.[1]

A total of 76 studies have found a correlation between fluoride exposure and decreased IQ.[2]

Water fluoridation is considered a form of medical treatment since its primary objective is to prevent tooth decay, not waterborne diseases. It is often implemented in communities without obtaining informed consent.

Fluoride tends to accumulate in the body and is stored in various tissues. In adults, approximately 40-60% of ingested fluoride is excreted daily, while the remainder is stored in bones and the pineal gland (in the brain). Children, on the other hand, can absorb up to 80% of ingested fluoride into their bones.

Systemic ingestion of fluoride hasn’t proven to be effective against tooth decay. So why is it added to drinking water?

Sources of fluoride

Tap water

In the UK, approximately 6 million individuals are supplied with artificially fluoridated water through their taps, predominantly concentrated in the East and West Midlands, as well as parts of the North East and East England. In contrast, the remaining regions of the UK are believed to have naturally-occurring fluoride in their water supplies. In Ireland, 73% of the population receive fluoridated water.

Those who support fluoride often claim that the notable decrease in tooth decay since the 1950s is primarily because of the widespread adoption of fluoridated water. However, tooth decay rates have actually dropped in all western countries, regardless of whether water fluoridation was practiced. Many western countries (including most of Europe) do not fluoridate their water, yet they have experienced comparable reductions in tooth decay.[3]


More than 95% of toothpastes contain fluoride, and a single strip of toothpaste applied to a child’s brush contains 0.75 to 1.5 mg of fluoride. Considering that the recommended daily dose of fluoride is 0.5 – 2mg for children and 3 – 4mg for adults, a single toothbrushing session can lead to excessive exposure to fluoride. Many young children, especially when unsupervised, swallow over 50% of the toothpaste, particularly if it has a sweet flavour such as bubble gum or strawberry. Studies have shown that some children consume more fluoride from toothpaste alone than the recommended amount from all sources combined. Ingesting toothpaste during childhood presents a notable risk for dental fluorosis and the symptoms of acute fluoride toxicity.[4] [5]

Dental fluoride treatments

Fluoride gels and varnishes are commonly prescribed for self-application at home or administered by dentists to those who at high risk of tooth decay. These treatments often contain between 5 – 20 mg of fluoride per application (which far exceeds the recommended daily dose) and without careful control to reduce ingestion, these treatments could lead to potentially hazardous levels of fluoride exposure. Despite dentists using suction devices and promoting thorough rinsing and spitting to minimise ingestion, children still swallow 7.7 mg and adults 10.3 mg of fluoride per treatment. It is not uncommon for children to experience nausea and vomiting following a fluoride gel treatment, indicating symptoms of acute fluoride toxicity.

Mouthwash and dental floss

Fluoride is added to certain mouthwashes and many brands infuse fluoride into their floss. There is approximately 1.25 to 3.75 mg of fluoride per serving of mouth wash.

Food and beverages

Foods that are processed with fluoridated water also contribute to fluoride intake. Sources include bottled beverages such as certain brands of water, fruit juice and soft drinks, black tea (has high levels due to the soil in which it grows), green tea (lower levels than black tea), canned food (soups, processed meats) and seafood (shrimp, crab).

Formula-fed babies

Formula-fed babies can be exposed to excessive levels of fluoride if their formula is mixed with fluoridated water instead of filtered water.


Certain medications such as anti-fungal drugs contain fluoride ions.

Why is fluoride harmful to health?

While excessive fluoride exposure can impact individuals of all ages, certain groups, including infants, pregnant women and those with diabetes and kidney disease, are particularly vulnerable to the effects of fluoride.

Dental fluorosis

This is a condition that causes white or brown spots on teeth due to overexposure to fluoride during tooth development. Fluorosis can occur in children who consume too much fluoride in their drinking water or toothpaste.[6]

Skeletal fluorosis

When fluoride is ingested, it can accumulate in the bones and teeth, which may result in increased calcification and potential weakening of the bones over time, leading to bone disease. It can also accumulate in soft tissues (including muscles) and excessive build-up can potentially cause skeletal damage. Long-term exposure to high levels of fluoride can cause skeletal fluorosis, a condition that causes joint pain, stiffness and bone fractures.[7] 

Hormonal and thyroid problems

There is a link between fluoride and thyroid problems, including an increased risk of hypothyroidism (under-active thyroid).[8] [9] [10] Fluoride shuts down the body’s ability to produce energy that mitochondria can use – these are the powerhouses of cells that are responsible for producing cellular energy.

Neurological issues

High levels of fluoride exposure have shown to affect brain function and cause neurological problems, including lowered IQ (especially in children), neurological inflammation and damage to brain cells. There is evidence to suggest that chronic exposure may induce learning difficulties, ADHD, decreased intelligence and memory deficits.[11] [12] Exposure to fluoride during pregnancy and early childhood has demonstrated negative impacts on the developing brain of a child.

Sleep issues

Fluoride can accumulate in the pineal gland (small endocrine gland in the brain) which can interfere with the production of melatonin, a hormone crucial for regulating sleep-wake cycles and circadian rhythms.

How to reduce your exposure to fluoride

Filter your water with a high-quality water filter specifically designed to remove fluoride such as reverse osmosis technology. This type of filter is effective in reducing fluoride levels so you have fluoride-free water for drinking, cooking and other household uses. To ensure the continued effectiveness of fluoride removal, it is important to change the filter cartridges when required.

Eat a healthy naturopathic diet that is rich in whole foods, including organic fruits and vegetables, that help support healthy teeth and gums. These nutrient-dense foods provide essential vitamins and minerals that contribute to strong dental health. Avoiding high-sugar foods and drinks is crucial, as sugar can fuel the growth of harmful bacteria that lead to tooth decay and gum disease. Limit your consumption of processed foods as some processed items are made with fluoridated water. Incorporate high calcium foods in your diet such as leafy greens, sesame seeds and almonds to help strengthen tooth enamel.

Use a fluoride-free toothpaste – this is key. Fluoride-free toothpastes contain ingredients like calcium carbonate (abrasive agent), herbal extracts (chamomile, aloe vera, tea tree oil, neem oil), essential oils (peppermint, spearmint, eucalyptus), sodium bicarbonate (bicarb), and silica (plaque removal and polishing). Brands like Kingfisher, Green People, Nelsons and AloeDent offer fluoride-free options for both adults and children. Alternatively, you can create your own natural toothpaste by mixing two teaspoons of 3% pure hydrogen peroxide with one teaspoon of bicarb. Ensure the hydrogen peroxide is 100% pure and additive-free.

Avoid fluoride-containing mouthwash. Instead, opt for a natural or herbal alternative formulated with plant-based ingredients like chamomile, sage or tea tree oil, or essential oils such as peppermint, spearmint or clove. These options do not contain fluoride or synthetic chemicals. Another option is a saltwater rinse which cleanses the mouth, reduces bacteria and soothes gum inflammation. Simply dissolve one teaspoon of sea salt or Himalayan salt (avoid table salt) in warm water and use it as a gentle mouthwash. Bicarb works just as well and can be used as an alternative to salt. For a homemade herbal mouthwash, infuse herbs like mint leaves, rosemary or calendula in water and use the strained liquid as a natural mouthwash.

Opt for fluoride-free dental treatments. If you require a dental procedure that typically involves fluoride, ask your dentist about fluoride-free alternatives. Some examples include remineralising gels or putties (such as Bliss Energetics) and herbal or mineral-based tooth polishes.

Cal Fluor is a homeopathic remedy that can be helpful for addressing dental fluorosis. Consult with a qualified homeopath who can advise on the correct dosage and frequency for your individual needs.

Maintain good dental hygiene by regularly brushing your teeth with a natural-bristle toothbrush, ideally after every meal. This habit effectively removes food particles and prevents the accumulation of plaque.

Stay hydrated by drinking filtered water throughout the day as it promotes saliva production and helps rinse away food particles and bacteria.

To learn more about supporting your health naturally and detoxing from harmful substances, take a look at the following short courses and resources: