Water fluoridation and hypothyroidism: results of this study need much more cautious interpretation

Dental caries remains a significant public health problem in many countries and an important cause of health inequalities. In England, almost a third of 5-year-old children and over two-fifths of 15-year-old teenagers are affected, and substantially higher rates of disease are seen among deprived communities.1 Dental disease can cause impaired nutrition and growth,2 ,3 and is one of the most common causes of child hospital admission. Long-term impacts on appearance, speech, schooling and self-confidence may add up to a substantial disadvantage for affected children. Water fluoridation schemes were first introduced in England in the 1950s and around six million people across the country now live in areas where the level of fluoride in drinking water is adjusted to an optimum level for oral health. Worldwide, hundreds of millions of people have experienced the benefits of water fluoridation for many decades. The possible health effects of water fluoridation have been studied and reviewed many times.4 ,5 The dental effects of fluoridation, namely reduced dental decay and dental fluorosis, are well described. Water fluoridation is one of the few interventions that can be expected to directly reduce public health inequalities, although …