Are high fluoride levels in drinking water associated with hypothyroidism prevalence in England?

Background and aims

The aim of this study was to examine whether there are differences in the prevalence of

drinking water.

We used a cross-sectional study design using secondary data to develop a linear regression model of

water, hypothyroidism prevalence data, the proportion of registered patients that were female and

of GP practices in areas with fluoride levels ?0.7mg/l to those with fluoride levels <0.3mg/l. We also

West Midlands Metropolitan County, a wholly fluoridated area; and Greater Manchester, a nonfluoridated

Results

the linear regression model. The model accounted for 52% of the observed variance and was

controlling for age and gender. The comparison of high and low fluoride areas showed a significantly

West Midlands Metropolitan County and Greater Manchester showed a higher mean practice level

significant.

The findings of the study show that higher levels of fluoride in drinking water are associated with a

confirmation of the findings of previous studies suggesting that ingestion of fluoride suppresses

thyroid function.