Aluminium In Drinking Water May Raise Alzheimer’s Risk

Much like lead, aluminium is a powerful neurotoxicant that can kill brain cells even at small concentrations, however studies into the role of aluminium in the development of Alzheimer’s disease have been relatively scarce. One area that has been examined is the relationship between aluminium concentrations in drinking water and the subsequent risk of Alzheimer’s disease.

In 1989, a study published in The Lancet, found that the risk of Alzheimer’s disease was 50% higher in areas of England and Wales where aluminium concentrations exceeded 0.11mg/L compared to areas with levels below 0.01mg/L.

A second study, published in the American Journal of Epidemiology in 2000, found a 99% increased risk of dementia, and a 114% increased risk of Alzheimer’s disease when concentrations of aluminium in drinking water exceeded 0.1mg/L. The researchers concluded that “our study suggests that a concentration of aluminum in drinking water above 0.1 mg/liter may be a risk factor of dementia and, especially, Alzheimer’s disease.”

Several mechanisms explaining the role of aluminium in Alzheimer’s disease have been proposed. It is believed aluminium may disrupt the blood brain barrier allowing amyloid beta, which would normally be stopped, to pass through the barrier and into the brain. Amyloid beta proteins are the primary component of the plaques observed in the brain of Alzheimer’s patients. A 1978 study published in the journal Biological Psychiatry found that brains of Alzheimer’s disease patients contained 1.4 times more aluminium than the brains of individuals free of Alzheimer’s. Furthermore, studies in mice have found neuron death, increased levels of inflammatory markers in the brain, and the development of lesions following the chronic administration of high levels of aluminium.

Aluminium is a non-essential element but is present in virtually all foods. Higher levels of aluminium can be found in spinach, tea leaves, potatoes, fish, certain types of processed cheese, baking powders that contain aluminium sulfate, and table salt which often contains the anti-caking agent sodium aluminosilicate. Most Americans consume between 1 and 10mg of aluminium a day from dietary sources however this amount pales into insignificance when compared to the intake of individuals who take aluminium based drugs. For example, those who regularly consume antacids with aluminium hydroxide as the active ingredient will likely have intakes in excess of 1 gram a day. Interestingly however, no link has been found between regular antacid use and an increased risk of Alzheimer’s disease although studies to date have been small.

Deodorants are another source of aluminium and while aluminium is not readily absorbed through the skin, some aluminium is unintentionally inhaled through the mouth and nose when deodorant sprays are applied. This study, found a slightly increased risk of Alzheimer’s disease in individuals using aluminium based antiperspirants.