Association between dental amalgam fillings and Alzheimer’s disease: a population-based cross-sectional study in Taiwan

INTRODUCTION: The potential effects of amalgam fillings on the development of Alzheimer’s disease (AD) are not well understood. The aim of the study was to evaluate the association between dental amalgam fillings and Alzheimer’s disease in Taiwanese population aged 65 and older. METHODS: Data were retrieved from the Longitudinal Health Insurance Database (LHID 2005 and 2010). The study enrolled 1,943,702 beneficiaries from the LHID database. After excluding death cases and individuals aged 65 and under, 207,587 enrollees were finally involved in the study. Dental amalgam fillings are coded as 89001C, 89002C, 89003C, 89101C, 89102C, or 89103C in the national health insurance research database (NHIRD). Alzheimer’s disease was diagnosed using the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes 331.0. RESULTS: Individuals exposed to amalgam fillings had higher risk of Alzheimer’s disease (odds ratio, OR = 1.105, 95 % confidence interval, CI = 1.025-1.190) than their non-exposed counterparts. Further analysis showed that the odds ratio of Ahlzheimer's disease was 1.07 (95 % CI = 0.962-1.196) in men and 1.132 (95 % CI = 1.022-1.254) in women. CONCLUSIONS: Women who were exposed to amalgam fillings were 1.132 times more likely to have Alzheimer’s disease than were their non-exposed counterparts.