This project examined the association between dietary patterns, erythrocyte membrane fatty acids concentration, and Alzheimer’s-related genes in systemic inflammation, as indicated by C-reactive protein (CRP) levels, in order to achieve more comprehensive knowledge of how nutrition and genetics influence systemic inflammation among the elderly residents of Cache County, Utah. First, the associations between dietary patterns defined by Dietary Approaches to Stop Hypertension (DASH) and Mediterranean dietary patterns (MED) and the risk of having a high level of CRP were examined. This study showed that a healthy dietary pattern score was associated with CRP levels; a higher score reflecting the ideal DASH diet and MED diet was associated with a 26% and 27% reduction in the risk of having high CRP levels respectively. This association appeared stronger among overweight and obese individuals. Second, the association between erythrocyte membrane fatty acids (EMFAs) and elevated serum C-reactive protein (CRP) levels was examined. Those that had high EMFAs composition of palmitoleic acid and nervonic acids, both monounsaturated fatty acids (MUFAs), and dihomo-y-linolenic acid (DGLA), docosapentaenoic acid (DPA-6), docosahexaenoic acid (DHA), all polyunsaturated fatty acids (PUFAs), had an increased risk of having CRP elevation. In contrast, risk of CRP elevation was reduced in those that have highest levels of saturated fatty acids (SFAs) of margaric acid, stearic acid, and arachidic acid. These associations were generally observed to be stronger among women compared to men. Lastly, the study examined whether AD-related genes identified in previous genome-wide association studies are associated with elevated levels of inflammatory CRP. Results revealed a strong association between APOE-epsilon genotypes and CRP levels. Results also showed an association between major alleles of APOE rs439401, TOMM40 rs157580, and minor alleles MMP8 rs1892886, CR1 rs6656401, CR1 rs3818361, and CR1 rs4844609 that were associated with a risk of elevation of CRP. These associations were stronger among men compared to women. Reduction in the prevalence of AD could have tremendous importance; the results of this dissertation may help identify factors important to AD etiology and, in turn, provide valuable targets for prevention.