Concentration of fluoride in our drinking water above certain level is linked to 30% increase in cases of thyroid problems, the latest research concludes, conducted by the scientists of the University of Kent at the Centre for Health Services Studies. ondition where thyroid produces less of key hormones needed for the body, called hypothyroidism, causes weight gain, depression and tiredness.
Fluoridation of water has been a public health policy for many years, aimed to protect the nation's tooth health, as fluoride helps reduce tooth decay. The researchers are now questioning the policy and calling to revise it, warning that adding fluoride to the water supply may be harmful.
Fluoride is a mineral found in water and certain foods, such as fish and tea. Adding additional fluoride to water and tooth paste has been considered a safe and effective public health measure in England.
In England, around 10 per cent of the population - amounting to six million people - live in areas with a naturally or artificially fluoridated water supply of 1mg fluoride per litre of drinking water.
The study was based on comparing the GP practices data reporting cases of underactive thyroid in two areas: Midlands - where drinking water is fluoridated, and Greater Manchester - where it is not.
The findings are that GP practices in the West Midlands reported nearly twice as high rates of hypothyroidism as those in Greater Manchester.
Scientists have found that, in areas where fluoride levels were above 0.7mg per litre, the higher than expected rates of hypothyroidism were reported by local GP practices than in areas with levels below this dilution.
High rates of hypothyroidism were at least 30 per cent more likely in GP practices located in areas with fluoride levels in excess of 0.3mg per litre.
The authors, led by Professor Stephen Peckham, conclude: 'Consideration needs to be given to reducing fluoride exposure, and public dental health interventions should stop [those] reliant on ingested fluoride and switch to topical fluoride-based and non-fluoride-based interventions.'
Some other expert disagree and question the results of the study.