Previous papers reported on the associations between water quality and a measure of cognitive impairment, based on data of the Ontario Longitudinal Study of Aging (LSA). The present report summarizes the information on fluoride (F) and aluminum (Al) and provides additional information on the effects of pH. Specifically, our preliminary results suggest that a neutral pH, relatively low Al and relatively high F concentrations in drinking water decrease the odds of showing indications of cognitive impairment by a factor of about five, compared with other types of drinking water. The relevant chemical reaction is ascribed to an equilibrium involving Al complexes.
