APOE Genotype and Diet Influences on Alzheimer's Biomarkers

The study will examine CSF biomarker responses to HIGH and LOW meals in 80 men and women with and without the E4 allele in a cross-over design. After an overnight fast, participants will ingest either a HIGH or LOW meal on separate days 3-5 weeks apart in random order. Three hours after meal ingestion, participants will undergo a cognitive battery, followed by spinal fluid collection. Blood samples will also be taken at 7 time points before and after meal ingestion.