Does fluoride pose a danger to children’s brains?

Fluoridated water

When I first moved to London from the North East of England, my dentist took one look at my teeth and said “you must have lived north of Tyne”.

Growing up, fluoridated water was standard in my home town of Whitley Bay – unlike 90 per cent of the country – and dentists could spot a clear difference in the teeth of North Tynesiders compared with those living less than half a mile across the river.

Fluoride appears to prevent tooth decay, accelerating the build-up of healthy minerals in the enamel and making teeth more resistant to acid erosion, which is why the Government is keen to expand fluoridation schemes.

But is that benefit coming with a hidden cost? A number of recent studies have suggested that fluoride exposure may damage the developing brains of children and harm pregnant women.

In 2020, York University in Ontario found that an increase of 0.5 mg/L of fluoride in water – approximately the difference between fluoridated and non-fluoridated areas – was associated with a 9.3-point decrease in IQ levels for bottle-fed babies when they reached primary school. Breast-fed children also saw their IQ levels dip by 6.2 per cent.

Last year the same team reported that fluoride may increase the risk of hypothyroidism in pregnant women. Fluoride’s ability to suppress the thyroid has been known since the 1930s, when it was used to treat an overactive thyroid.

In Canada, where the studies took place, the recommended level of water fluoridation is 0.7 mg/L, yet in Britain it is 42 per cent higher, at 1 mg/L. The Drinking Water Inspectorate will only step in if it rises above 1.5 mg/L.

Link to more errors in drawing and memory

Last October, Tulane University in New Orleans found that higher exposure to fluoride in drinking water was linked to more errors in drawing and memory tests in 74 school-aged children in Ethiopia – although levels in the study were often far higher than in Britain.

Stephen Peckham, professor of health policy at the University of Kent, said: “The benefits of fluoridation are hugely overstated and there is significant evidence of harm in terms of neurotoxicological effects.

“Recent high-quality UK studies show how limited the benefits to dental decay are. Oral health in Scotland has significantly improved without fluoridation. The Government and dental lobby are wrong to keep overstating the benefit and saying fluoridation is safe and effective.”

Fears over fluoride have reached a head in San Francisco, where the US Environmental Protection Agency (EPA) is being taken to court by the Fluoride Action Network over claims the mineral is damaging the neurodevelopment of foetuses and children.

It was sparked by a draft report from the US Department of Health’s National Toxicology Programme which looked at 55 studies and found: “When compared to children exposed to lower levels of fluoride, children exposed to higher fluoride levels had statistically significantly lower IQ scores.”

The report, which took three years to complete, has proved controversial and been subject to two reviews by the National Academies of Sciences, Engineering, and Medicine, who claim the authors failed to provide adequate support for their conclusions and asked for a substantial rewrite.

The amended version has yet to be formally released, although it was signed off by the National Toxicology Programme in May 2023 and sent to NTP leadership for approval, with the authors largely sticking to their guns.

‘If it was toxic, the Russians would be using it’

Barry Crockroft, the former chief dental officer for England, and now chairman of the British Fluoridation Society, remains unconvinced.

“If it was toxic, the Russians would be using it,” he said. “There is a health monitoring programme carried out on a rolling basis and there has never been any disease which has shown up as linked.

“You can never prove a negative. I could suggest that chocolate biscuits cause dementia, God forbid, but nobody has done the research to show it is not true.”

As with all medicines or interventions, the dose makes the poison, and there is great uncertainty about the level at which fluoride may become harmful.

Some areas of the world naturally have very high levels of fluoride, and it is known to lead to dental fluorosis or crippling skeletal fluorosis, which can lead to calcification of tendons and ligaments, and bone deformities

The World Health Organisation currently recommends a limit of fluoride in drinking water at 1.5 mg/L, but it is impossible to know how much extra fluoride people are consuming through other means.

Coffee, tea, wine, grapes, potatoes and seafood are all known to be high in fluoride, and any food prepared in fluoridated water will also pick up traces of the mineral.

Fluoride is also present in baby formula, which could explain why bottle-fed babies in fluoridated areas of Canada suffered bigger drops in IQ than breast-fed youngsters.

Low-IQ could be related to other factors

But the low-IQ effect could also be an artefact of other issues. Areas chosen for fluoridation are often the most deprived, and so it is difficult to tease apart the reasons for low-educational achievement, or illness.

The North East and the West Midlands already have some of the lowest IQ scores in the country and the worst health.

And research has been conflicting. A study published by the University of Queensland in October 2022 found that children who grew up drinking fluoridated water had no worse emotional, behavioural or executive functioning issues by the time they reached adolescence than other youngsters.

In 2023, the California Department of Public Health carried out a meta-analysis and concluded water fluoridation was not associated with lower IQ scores in children.

Critics argue that studies showing a link to neurodevelopmental problems have failed to take into account other water-borne contaminants, such as arsenic, or fluoride taken in from coal used in indoor fires.

The San Francisco court case may be the best chance of coming to a consensus on the issue and over the next fortnight, Judge Edward Chen will be hearing the views of seven experts on the subject.

Judge Chen has already said that the EPA will be forced to regulate fluoride if the court case proves an “unreasonable risk” to children and pregnant women.

But the case has been rumbling on since June 2020 with little progress, and the court is unlikely to rule before Britain rolls out further fluoridation.

For now, all we can do is sip it and see.

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