About Alzheimer's & Aluminum
Alzheimer's disease is characterized by two major changes that occur within the brains of afflicted individuals--the loss of brain cells and the development of plaques and tangles in brain tissue. Plaques are abnormal deposits of the protein beta amyloid between brain cells; tangles are abnormal deposits of the protein tau within the cells themselves. Both plaques and tangles decrease the ability of the brain to function optimally. Together, with brain cell loses, the plaques and tangles result in the major symptoms of Alzheimer's: the progressive loss of memory and, slowly, all other higher order mental functions.
While no one cause for Alzheimer's has been identified, researchers believe that there are a number of risk factors that can affect an individual's chances of developing the disease in the future. These risk factors include: age, gender (women are slightly more likely to develop the disease than men), the presence of the gene apolipoprotein E (APOE), specific medical conditions, a diet high in saturated fat and low in fruits and vegetables, smoking, excessive alcohol consumption, lack of physical exercise and, possibly, high concentrations of aluminum in the brain.
Aluminum was first considered as a possible cause of Alzheimer's in the mid 1960s. Since then, there have been a large number of research studies that seem to provide circumstantial evidence of the link between the two.
The plaques and tangles present in the brains of people with Alzheimer's have been shown to have unusually high levels of aluminum, and a variety of experimental studies have connected aluminum exposure with nervous system damage.
The difficulty with definitively calling aluminum a contributing factor to Alzheimer's disease, however, is the nature of the findings themselves. While many researchers reported that Alzheimer's patients had elevated levels of aluminum in their brains, this finding did nothing to actually prove that the aluminum's presence was what caused the plaques, tangles, and loss of brain cells inherent in the disease.
Likewise, a growing body of studies have revealed information that seems to directly contradict aluminum being a cause of Alzheimer's; for instance, people suffering from kidney failure cannot excrete aluminum from their systems and must be treated with drugs that contain aluminum. Yet, kidney failure patients show no greater tendency towards developing Alzheimer's than other segments of the population.
In 1989, after reviewing all of the available data on the possible relationship between aluminum and the development of Alzheimer's disease, researchers concluded that there is simply not enough evidence to indicate a direct causal relationship between the two, and that no medical or public health recommendations could be made with respect to limiting the amounts of aluminum exposure for individuals.
