Did you know that the development of Alzheimer’s disease actually starts in the brain 20 to 30 years before any dementia symptoms appear? This is particularly true for people who carry the Apolipoprotein e4 (APOE4) gene, which is the most significant genetic risk factor for Alzheimer’s. Individuals with one or two copies of the APOE4 gene have a 4- to 8-fold higher risk of developing the disease and may experience symptoms 7 to 15 years earlier than those without the gene. Interestingly, even in their 20s and 30s, young individuals who are cognitively normal but carry the APOE4 gene have shown reduced brain blood flow and metabolism, even before the accumulation of amyloid beta plaques or tau tangles.