Silicon and Alzheimer's Disease (Research)

Peer-Reviewed Professional Journals

·    Exley, C., et al.  Non-invasive therapy to reduce the body burden of aluminium in Alzheimer's disease.  J Alzheimers Dis.  10(1):17-24, 2006.

Birchall Centre for Inorganic Chemistry and Materials Science, Keele University, Staffordshire, UK.

There are unexplained links between human exposure to aluminium and the incidence, progression and aetiology of Alzheimer's disease.  The null hypothesis which underlies any link is that there would be no Alzheimer's disease in the effective absence of a body burden of aluminium.  To test this the latter would have to be reduced to and retained at a level that was commensurate with an Alzheimer's disease-free population.  In the absence of recent human interference in the biogeochemical cycle of aluminium the reaction of silicic acid with aluminium has acted as a geochemical control of the biological availability of aluminium.  This same mechanism might now be applied to both the removal of aluminium from the body and the reduced entry of aluminium into the body while ensuring that essential metals, such as iron, are unaffected.  Based upon the premise that urinary aluminium is the best non-invasive estimate of body burden of aluminium patients with Alzheimer's disease were asked to drink 1.5 L of a silicic acid-rich mineral water each day for five days and, by comparison of their urinary excretion of aluminium pre-and post this simple procedure, the influence upon their body burden of aluminium was determined.  Drinking the mineral water increased significantly (P<0.001) their urinary excretion of silicic acid (34.3 +/- 15.2 to 55.7 +/- 14.2 micromol/mmol creatinine) and concomitantly reduced significantly P=0.037) their urinary excretion of aluminium (86.0 +/- 24.3 to 62.2 +/- 23.2 nmol/mmol creatinine).  The latter was achieved without any significant (P>0.05) influence upon the urinary excretion of iron (20.7 +/- 9.5 to 21.7 +/- 13.8 nmol/mmol creatinine).  The reduction in urinary aluminium supported the future longer-term use of silicic acid as non-invasive therapy for reducing the body burden of aluminium in Alzheimer's disease.

·    Gillette-Guyonnet, S., et al.  Cognitive impairment and composition of drinking water in women: findings of the EPIDOS Study.  Am J Clin Nutr.  81(4):879-902, 2005.

The concentration of aluminum or silica in drinking water may be a potential environmental risk factor for Alzheimer disease (AD).  The objective was to investigate at baseline the potential association between the composition of drinking water and the level of cognitive function in women taking part in the Epidemiology of Osteoporosis (EPIDOS) Study and to determine during follow-up the effects of the composition of drinking water on the risk of AD.  Women aged >/=75 y (n = 7598) were recruited between 1992 and 1994 in 5 geographic areas of France.  The participants from one center (n = 1462) were followed for </=7 y; during this time, an active search for incident cases of AD was conducted.  The initial questionnaire comprised a food consumption survey with specific questions about the daily consumption of tap and mineral water.  The evaluation of cognitive function was based on the Short Portable Mental Status Questionnaire.  During follow-up, the diagnosis of dementia was made by a geriatrician and a neurologist.  A low silica concentration was associated with low cognitive performance at baseline.  Compared with the nondemented subjects, the women with a diagnosis of AD during follow-up were older at inclusion, had a lower financial status and educational level, had a poorer perception of their own health, and had a more difficult time performing activities of daily living.  A multivariate analysis including potential confounding factors showed that women with AD appeared to have been exposed to lower amounts of silica at baseline.  Silica in drinking water may reduce the risk of developing AD in elderly women.  The results corroborate those of another epidemiologic study carried out in France.  The potential effect of silica needs to be confirmed in additional investigations.

Laypersons’ Publications

·    Bitomsky, M.  Herbs falling into favor down under.  Life Extension.  6(3):40-46, 2000.

Silicon has been identified as a possible protective factor against Alzheimer’s disease.

·    Foster, Harold, J.  What Really Causes Alzheimer’s Disease., 2004.