The case against aluminum as a risk factor
Last week we presented studies that made the case for aluminum as a risk factor for Alzheimer's disease. But when you look beneath the surface of these studies, there are some serious flaws that cast doubt on their validity. For example, it was discovered that the presence of aluminum in dialysis fluid was the major reason for the development of dialysis encephalopathy in patients with kidney failure..
But the similarity of the dementia of dialysis encephalopathy to Alzheimer's disease is only superficial. Seizures are a typical cause of death in patients with dialysis encephalopathy, but they are rarely seen in Alzheimer's disease. In dialysis encephalopathy, death follows six months after initial symptoms. In Alzheimer's disease, death usually follows five to ten years after initial symptoms. Finally, the brain changes in dialysis encephalopathy differ from those in Alzheimer's disease; for example, patients with dialysis encephalopathy do not develop neurofibrillary tangles despite an elevated brain aluminum content.
Amyotrophic lateral sclerosis and Parkinson's dementia of Guam - The high concentrations of aluminum in the water of Guam is not the only feature of this island. Another is the inclusion of the seeds of the false sago palm in the population's diet. These contain a toxic amino acid, which, when given to monkeys, caused a degenerative disease similar to amyotrophic lateral sclerosis. Furthermore, while the Guam brains did exhibit neurofibrillary tangles, no amyloid plaques were observed in the Guam brains; whereas they are frequent in Alzheimer's disease cases.
Antiperspirants and antacids - The study done in 1990 on antiperspirants and antacids found an increased risk of Alzheimer's disease with the use of antiperspirants but no increased risk with the use of aluminum-containing antacids. The study had serious methodology problems so that the result on antiperspirants is in doubt.
Desferrioxamine or DFO - DFO's actions as a chelating agent are not confined to aluminum. DFO removes other metals as well, including iron. Iron is known to have neurotoxic effects. DFO also has anti-inflammatory effects. Anti-inflammatory agents have been demonstrated to have a beneficial effect on Alzheimer's patients.
Aluminum in the water supply - If subjects who took aluminum antacids, which contain very high levels of aluminum, failed to show any excess risk of Alzheimer's disease, it would seem improbable that exposure to relatively small amounts from drinking water could cause the disease. Drinking water, even at high aluminum concentrations, contribute only a fraction of the total dietary intake of aluminum. Regular consumers of antacids ingest thousands of times the amounts taken in through drinking water, and epidemiological studies of antacid use have not shown them to increase the risk of Alzheimer's disease. It is possible that other confounding agents in the water could be the cause.
The controversy over aluminum and Alzheimer's disease rages on. But whether or not aluminum causes Alzheimer's disease, everyone agrees that it is a neurotoxic substance. As such, it is something that it would be prudent to avoid.
Sources of aluminum in the environment
For most people the greatest source of aluminum comes from processed foods containing aluminum additives. Sodium aluminum phosphate is an emulsifier in processed cheese; potassium alum is used to whiten flour; and aluminosilicate is added to common table salt to help it run freely and not cake. Foods containing high concentrations of aluminum include pancakes, waffles, biscuits, muffins, cornbread, tortillas, doughnuts, cookies, cakes, pastry, baking powder, cake mixes, frozen dough, self-rising flour, American cheese, chocolate pudding, chocolate milkshakes, hot chocolate, pickles, tea, and some non-dairy creamers. Aluminum is also ingested with the soda in aluminum soda cans.
Aluminum is in vaccines and intravenous fluids. It is found in over-the-counter products such as antiperspirants, some deodorants, aluminum-containing antacids, buffered aspirin, and toothpaste and shampoo containing aluminum lauryl sulfate.
This list is not exhaustive, and there are undoubtedly many other sources of aluminum in food, medicines, and cosmetics that have been omitted. Therefore, it is important to read labels and check for the aluminum content in the product you are purchasing. It is probably also a good idea to err on the side of prudence and avoid aluminum pots and pans.
The mechanism by which aluminum is toxic to nerve cells is unknown, but there is evidence that aluminum can cause inflammation, and inflammation is thought to play a role in Alzheimer's disease.
Mary Lou Williams, M. Ed., is a lecturer and writer in the field of nutrition and a Whiskey Creek resident.. She welcomes inquiries. She can be reached at 267-6480.