Dear Editor,

A report published on March 26 by Public Health England has concluded that there is no evidence of higher cancer rates in areas with fluoridated tap water, compared to those without fluoridation.

The report also concludes that incidence rates for bladder and bone cancer are the same in fluoridated and non-fluoridated areas.

These observations were based on a study of cancer incidence in the entire population of England in 2007-2010, 12 per cent of whom lived in fluoridated areas.

The study covered a population of more than 50 million people, with more than 1 million cancer cases and would have had the power to detect even very small increases in risk.

This very large study adds to the considerable evidence that while fluoridation of water improves dental health, it is not a risk factor for cancer.

Given the very large size of the English study and the absence of any detectable effect of fluoride on cancer rates, it is clear that water fluoridation practice cannot be responsible for large international differences in cancer incidence, as has been suggested in these pages recently by some anti-fluoridation groups.

To explain these differences, and the relatively high incidence of cancer in Ireland, we need to look at those factors which have been proven beyond doubt to cause cancer — smoking, obesity, lack of exercise, alcohol consumption, sexual and reproductive life and UV exposure.

Unfortunately, international evidence shows the prevalence of many of these risk factors to be relatively high in Ireland.
These, and not water fluoridation, are the real priorities for action in our population.

Dr Harry Comber,
National Cancer Registry.