Principal Component Analysis Applied to Alzheimers Disease: USA by State
Principal Component Analysis (PCA) of Alzheimers disease (AD) and twelve epidemiological and socio-economic components of the USA states inform etiology by extracting large scale patterns. The twelve components demonstrate simple pairwise Pearson correlations to AD, and then are analyzed by PCA for loadings associated with AD. Repetitive factor analysis and the culling of questionable data reduced the factors (all per capita) associated with AD to two, one factor with the components dentists and wine consumption and another factor with the components beer consumption and dentists. Dentists and wine are likely associated with reduced AD incidence because of the known inverse association with elevated education. Dental care is known to be inversely associated with AD incidence. The contribution of beer consumption to AD incidence is likely because of the negative effect on the innate immune system from either phytoestrogens in hops, or detritus from fermentation permitting the fungal colonization seen in AD brains.