Senile dementia is a progressive degenerative brain disease associated with old age. Its symptoms include short-term memory loss, slowness in thought and movement, confusion, disorientation, depression, difficulty communicating, and loss of physical function. Alzheimer's disease accounts for about half of all senile dementia cases. Although there are many theories about what causes Alzheimer's, the fact is, its origins remain poorly understood.
One theory proposed that the common occurrence of being exposed to aluminum could cause Alzheimer's dementia. Aluminum, the theory postulated, becomes concentrated in the characteristic lesions (senile plaques and neurofibrillary tangles) that develop in the brain during the course of the disease. At first, medical scientists thought this theory was absurd. Aluminum, they believed, accumulated merely as a result of a destructive process caused by some other factor.
In recent years, however, the aluminum hypothesis has been gaining respect. For example, studies have discovered a direct association between the level of aluminum in municipal drinking water and the risk of Alzheimer's dementia. One study found aluminum in drinking water was related to only this specific type of dementia;1 another found that the probability of the association being due to chance was only 1 in 24, with a 46 percent increased risk for people drinking water with the highest aluminum levels.2
The use of aluminum-containing antiperspirants--but not the use of antiperspirants and deodorants in general--has also been associated with a risk of Alzheimer's dementia, with a trend toward a higher risk corresponding with increasing frequency of use.3 This relationship does not extend to aluminum-containing antacids,4 which may simply be evidence that the aluminum in antacids is not absorbed--the process of absorption through the gut mucosa is quite different from absorption through the skin.
We also know that serum aluminum concentrations increase with age. Aluminum may accumulate slowly over our lifetimes or we may absorb it more easily as we age. Moreover, there is evidence that people with probable Alzheimer's disease have serum aluminum levels that are often significantly higher than those of people with other types of dementia, as well healthy people of similar ages.5
Further evidence that aluminum fosters the development of Alzheimer's dementia comes from a scientific (placebo-controlled) trial of desferrioxamine, a drug that removes aluminum from the body by binding with it. While regular administration of the drug failed to stop the disease from progressing, desferrioxamine did significantly reduce the rate of decline in the ability of a group of people with Alzheimer's dementia to care for themselves.6
Although the aluminum/Alzheimer's link remains unproven, I believe that waiting for definitive proof before taking a few easy and protective measures is foolhardy--and more scientists are starting to agree.7,8 Perhaps one person in 10 age 65 or older suffers from dementia; by age 80 that figure rises to one in five. This is too common an illness to ignore preventive measures until we can know for certain why it develops.

Ways To Avoid Aluminum

Here are my suggestions for minimizing your exposure to aluminum.
* Drinking water should be low in aluminum. Some bottled-water companies provide an analysis of the aluminum content of their water. You might also find out from your public water company what the aluminum level is in the local drinking water.
* Aluminum-containing antiperspirants can easily be avoided, as can aluminum utensils and even, to play it safe, aluminum-containing antacids.
* Commercially processed foods such as cake and pancake mixes, frozen doughs and self-rising flour are sources of dietary aluminum, so their ingestion should be minimized. Watch for and avoid sodium aluminum phosphate, an ingredient in baking powder. Pickles and cheese should also be avoided.
* There is a close relationship between silicon and aluminum in Alzheimer brain lesions, as the two substances bind together to form aluminosilicates.9 High levels of silica in drinking water in the form of silicic acid do seem to protect against the adverse effects of aluminum ingestion, and silicic acid ingestion increases urinary aluminum excretion.10,11 Whether silica supplements protect against the development of dementia has yet to be determined.
* Besides minimizing aluminum exposure, taking the Recommended Dietary Allowance (RDA) of calcium, magnesium and zinc should help to protect against aluminum accumulation.12-14 Deficiencies of these important minerals are common among the elderly.15 Yet, unless there is laboratory evidence of a zinc deficiency, I would not recommend zinc supplementation to help prevent Alzheimer's disease, for two reasons. First, beta-amyloid protein, the major substance found in the brain lesions (usually in a liquid form), binds with zinc. At concentrations only slightly higher than those normally found in the brain, excess zinc may convert the protein to the solid form that is found in Alzheimer lesions.16 This suggests that, at least in theory, excess zinc could actually promote the development of the disease. Second, there is a lack of adequate research demonstrating the efficacy of zinc supplementation in preventing Alzheimer's, although in one study all six relatively young dementia victims had some memory improvement following supplementation with zinc aspartate.17

References
1. Martyn, C.N., et al. Lancet, 1: 59-62, 1989.

2. Neri, L.C., & Hewitt, D. Letter. Lancet, 338: 390, 1991.

3. Graves, A.B., et al. J Clin Epidemio,l 43(1): 35-44, 1990.

4. Ibid.

5. Zapatero, M.D. Biol Trace Elem Res, 47: 235-40, 1995.

6. McLachlan, D.R., et al. Lancet, 337: 1304-8, 1991.

7. Lukiw, W.J. Mineral and Metal Neurotoxicology. 113-26. CRC Press, 1997.

8. McLachlan, D.R., et al. Can Med Assoc J, 145(7): 793-804, 1991.

9. Candy, J.M., et al. Lancet, i: 354-57, 1986.

10. Jacqmin-Gadda, H., et al. Epidemiology 7(3): 281-85, 1996.

11. Bellia, J.P., et al. Ann Clin Lab Sci, 26: 227-33, 1996.

12. Foster, H.D. Health, Disease and the Environment. 311-16. Boca Raton, Fla.: CRC Press, 1992:

13. Durlach, J. Magnes Res, 3(3): 217-18, 1990.

14. Wenk, G.L., & Stemmer, K.L. Brain Res 288: 393-95, 1983.

15. Werbach, M.R. Foundations of Nutritional Medicine: Common nutritional deficiencies. Tarzana, Calif.: Third Line Press, 1997.

16. Bush, A.I., et al. Science, 265: 1464-67, 1994.

17. Constantinidis, J. Schweiz Arch Neurol Neurochir Psychiatr, 141(6): 523-56, 1990.
Melvyn R. Werbach, M.D., is a faculty member at the UCLA School of Medicine and the author of Nutritional Influences on Illness (Third Line Press Inc., 1993).

Melvyn R. Werbach, M.D., is a faculty member at the UCLA School of Medicine and the author of Nutritional Influences on Illness (Third Line Press Inc., 1993).