According to a study published in the British Journal of Psychiatry, higher levels of aluminium and fluoride are associated with the risk for dementia in men and women who consumed relatively low drinking-water levels of both.
Aluminium is widely used for reducing organic matter in water treatment and to improve other water parameters. Low fluoride levels in drinking water are beneficial for teeth but high levels are harmful, and both these substances are widely present in drinking water, although at levels considered acceptable.
Researchers used data from the Scottish Mental Survey, 1932 to investigate the association between mean aluminium and fluoride levels in drinking water (collected 2005-2012 by the Drinking Water Quality Regulator for Scotland) with dementia in participants who were alive in 2005.
Results showed that 1972 out of 6990 individuals developed dementia in 2012. The risk for dementia increased with rising mean aluminium levels in women (HR per standard deviation [SD] increase 1.09; 95% CI, 1.03-1.15; P<.001) and men (1.12; 95% CI, 1.03-1.21; P=.004). Researchers also found that higher mean fluoride levels in drinking water were associated with an increased risk for dementia in men (aHR per SD increase 1.30; 95% CI, 1.22-1.39; P<.001) and women (aHR per SD increase 1.34; 95% CI, 1.28-1.41; P<.001) in a stepwise pattern. No statistical interaction was found between aluminium and fluoride levels in relation with dementia.
“Our findings suggest that even these relatively low levels of aluminium and fluoride are associated with deleterious effects on dementia risk, which should be weighed against their beneficial uses,” the authors said.
“However, this is clearly an area which deserves further investigation, given the substantial and growing global public health impact of dementia,” they added.
