APOE Genotype and Diet Influences on Alzheimer's Biomarkers

This study involves the collection of cognitive and biomarker responses to HIGH and LOW meals in healthy older adults with and without the APOE E4 genotype. Subjects will eat the meal after an overnight fast, followed by cognitive testing, spinal fluid and blood collection. The HIGH meal will be a meal high in saturated fat and high glycemic index foods vs. LOW meal which will be low in saturated fat and low glycemic index foods.