The ever-widening income gap between the richest and poorest among us is also creating an expansive yawn in life expectancy.

Researchers have long known there is a link between wealth and longevity. But a new in-depth study published in the Journal of American Medical Association (JAMA) reveals, among other things, just how many more years money can buy.

The top 1 percent of earners tend to live about 15 years longer than the poorest 1 percent for men. For women, the difference in life span is about 10 years.

Led by a Stanford University economics professor, the research team came up with their findings by relying on two certainties: death and taxes. They combed through mortality data and tax returns filed by every American between 1999 and 2014.

Other key findings include:

• Life expectancy for the rich grew over time. For men, it increased by about 2 years and for women, it jumped by about 3 years.

• For the poor, life spans stayed relatively the same over time.

• Where you live can affect how long you live — if your income is low. Poor people living in San Francisco, for example, tended to live longer than those living in Detroit. Researchers suspect this has to do with health behaviors such as smoking. In San Francisco, smoking is banned from restaurants and bars.

"Income matters in health, and the report … confirms this," Dr. J. Michael McGinnis, of the National Academy of Medicine, wrote in an accompanying editorial.

"But it also presents important insights as to the many other ways in which communities shape life prospects, and, as such, suggests both the promise of learning much more about the dynamics in play, while strengthening communitywide public health approaches to better capture opportunities at hand."

Read the full study here.

"To Your Health" offers quick doses of health news several times a week.

Allie Shah • 612-673-4488

@allieshah