What role does APOE play in Langlebigkeit?

APOE (apolipoprotein E) is one of the most robustly studied genes in human longevity. Its three common alleles—ε2, ε3, and ε4—differentially affect lipid metabolism and neurodegeneration. The ε4 allele is the strongest known genetic risk factor for late-onset Alzheimer's disease and is consistently associated with reduced lifespan. Conversely, the ε2 allele shows a modest protective effect and is enriched in centenarians. However, these associations are population-specific and modified by lifestyle factors such as diet, exercise, and cognitive engagement. A direct-to-consumer APOE test can provide risk information but cannot predict individual longevity. The evidence is strong (human-strong) from large cohort studies and meta-analyses. Caveat: APOE is one of many genetic and environmental contributors; no single gene determines lifespan. Safety note: ε4 carriers should be aware of increased Alzheimer's risk and consider preventive strategies, but no specific medical action is mandated.