Even an apparently small amount of fluoride transferred from the mother during her pregnancy to the fetus can damage the fetal brain development.

By Marianne Lie Becker, [email protected]

This association has previously been supported by a multitude of studies, but a new study led by Professor Philippe Grandjean, MD, now documents the linkage in a joint study of more than 1500 mother-child pairs from cohorts in North America, now also including births in Denmark. 

The fluoride concentrations in Danish drinking water are generally low, but they may be complemented by the ingestion of toothpaste and by drinking certain types of black tea. Although fluoride exposures in the Danish women were comparatively low and similar to Canadian women from non-fluoridated cities, the cohorts overlapped in exposure levels, so that the researchers could generate joint conclusions from all the cohorts.