80% to 90% of a person's rate of aging is determined by how they live their life.

“The claim that lifestyle is the dominant factor in aging is broadly supported by scientific consensus, though the exact percentage varies. Some sources, like the Mayo Clinic, state that genetics account for no more than 20% of longevity, which implies lifestyle and environment determine the other 80%. Other estimates suggest genetics account for about 25% of the variation in human lifespan, leaving 75% to non-genetic factors. However, more recent 2026 research suggests the genetic component could be as high as 50-55%, which would lower the lifestyle contribution. The 80-90% figure is on the higher end of estimates but aligns with some models. Context: While there is a strong consensus that lifestyle and environment are major determinants of aging and longevity, the precise contribution of genetics is still debated. Older and more conventional estimates place the genetic contribution at around 20-25%, making the 80% lifestyle figure plausible. However, some newer research from early 2026, which attempts to control for external causes of death, suggests the genetic component could be closer to 50%.”