In 1988–1991, older adults infected with CagA strains of H. pylori had a 50% borderline statistically significant increased level of cognitive impairment, as measured by low Mini-Mental State Examination (MMSE) scores (age–education adjusted prevalence ratio: 1.5; 95% confidence interval: 1.0, 2.0). This evidence concerns the gene S100A8 and Cognitive impairment.