There are a large number of potential risk factors for Alzheimer's disease and one environmental factor that has been linked with a greater risk of the condition is aluminium. French researchers have been following a group of older people over 15 years to investigate the links between aluminium and silica in drinking water and the risk of cognitive decline, dementia and Alzheimer's disease. An intake of 0.1 mg of aluminium or more per day was linked to a 2.26x greater risk of dementia. However, silica, which is thought to either stop aluminium being absorbed by the body in the first place or to encourage its excretion, reduced the risk of dementia. For every 10mg per day intake of silica the risk of developing dementia dropped by 11%.
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