10. Medical and Public Health Advances Have Already Extended Human Life Expectancy

Much of the historical increase in human lifespan came from reducing extrinsic mortality and lowering early-life deleteriome loads: sanitation, vaccines, antibiotics, safer childbirth, and better nutrition. Reducing lifelong damaging exposures may lower biological age at a given chronological age. This could raise mean lifespan with little change in maximal lifespan if the longest-lived individuals in earlier generations already experienced few exposures. This perspective also highlights a reduction in lifelong burden accumulation by improving environment, not only by developing new drugs.