Two more researchers have responded to this question. Leonard Berg is a professor of neurology at the Washington University School of Medicine in St. Louis; until recently, he directed the Alzheimer's Disease Research Center there. He replies:
"There is no proof, and the current consensus is that aluminum does not play a major role in the development of Alzheimer's disease. But because the causes of the disorder are not understood at this time, one cannot rule out the possibility that aluminum could play a minor role. In our Center, we do not recommend that people avoid aluminum cooking pans or aluminum-containing antiperspirants or antacids because there is little evidence that such lifestyle changes are helpful. Moreover, it is impossible to avoid ingesting a certain amount of aluminum, which is found naturally in food and water."
Zaven S. Khachaturian is the director of the Ronald and Nancy Reagan Research Institute. He has written a review article on the disease in July/August issue of The Sciences. He adds:
"This issue has been the subject of many studies, workshops and reports since the early 1970s. Unfortunately, there is no clear-cut answer either to implicate or to absolve the role of aluminum in causing Alzheimer's disease. At present it is not clear whether the aluminum found in the brain of an Alzheimer's victim got there because there is disease already in progress or if the aluminum starts the process.
"In the mind of many scientists, if aluminum plays a role it is most probably a secondary one. The reasoning for this position is based on the fact that aluminum is one of the most abundant and pervasive elements. It is found everywhere--it is in the water we drink, it is in the dust we breathe, it is in many of he substances we use every day such as coke in glass bottles, food preservatives, many cosmetics and food dyes. Even if we stop using pots and pans or underarm deodorants, it will be virtually impossible to avoid aluminum. Given this type of exposure of the general population, if aluminum is playing a major role then one would expect the numbers of people affected by Alzheimer's to be much higher than they are found in epidemiological studies."
The link between aluminum and Alzheimer's disease is tentative at best. Charles DeCarli, director of the Alzheimer's Disease Center at the University of Kansas Medical Center, explains:
"I believe the connection between aluminum and Alzheimer's Disease is a myth which comes from two sources:
"First, in the past, patients undergoing renal dialysis would often become confused. When renal failure occurs, the body cannot remove aluminum from the blood. In some regions, the water used for the dialysate contained a lot of aluminum. Some patients also used aluminum-containing medications. The amount of aluminum in the blood seemed to correlate with the amount of confusion the patients displayed; the concentration of aluminum in the blood of the confused patients was thousands of times higher than normal. Doctors subsequently started using purified water in renal dialysis and reducing the amount of aluminum-containing medication prescribed, which has greatly diminished the problem. When researchers realized that aluminum buildup in the bloodstream can cause confusion, they turned their attention toward the role of aluminum in Alzheimer's Disease. But the confusion associated with aluminum toxicity in dialysis patients is much different than the confusion of Alzheimer's. To date, there is no conclusive evidence that patients experiencing aluminum toxicity have a greater incidence of Alzheimer's Disease.
"Second, researchers found aluminum in plaques present in the brains of people who had suffered from Alzheimer's. These plaques are associated with lesions of the brain that contain amyloid protein, which is thought to damage nerve cells and thereby cause Alzheimer's. Unfortunately, these findings were again compromised by contamination. The plaques are 'sticky'; the water used to wash the tissue to prepare for staining included some aluminum. When the tissue was processed using more sophisticated analytical methods, or when more accurate measures of aluminum content in the Alzheimer's-diseased brain were used, no excess aluminum was found. In addition, studies of the total amount of aluminum in the body of patients with Alzheimer's Disease show no increase in aluminum concentrations as compared to healthy individuals.