Predicting lifespan isn’t an exact science. U.S. life expectancy is currently estimated at 78.6 years, but that one number doesn’t tell the whole story. Genes, gender, lifestyle and luck all play an important part, but it’s impossible to know exactly how much and in what proportion each ingredient influences a person’s longevity.
The single best predictor, though, might not be one of these factors at all. A growing body of evidence suggests it may be a person’s zip code that holds the most information about how long they’ll live. Researchers from the New York University School of Medicine recently used data from NYU Langone Health’s City Health Dashboard to find that 56 of the U.S.’ 500 largest cities are home to people who can expect to live at least 20 fewer years than those in other neighborhoods, even if they’re just blocks or miles away.
In Chicago, the city with the largest disparity, life expectancy varied by up to 30.1 years, and in both Washington, D.C. and New York City it varied by more than 27 years. Meanwhile, residents of Fishers, Ind., the city with the smallest gap, can expect to die within about 2.5 years of their neighbors across the city.