It's a good time to be alive in America — that is, if you're rich. New studies show life expectancy is on the rise in the U.S. for both men and women. But that's mainly for those at the top of America's income ladder. And the widening gap in the life expectancy between this country's rich and poor is drawing the attention of everyone from health care researchers to politicians.

It's no secret that the rich live longer than the poor. But even with advances in health care, education and technology, that gap is widening at an inexplicable rate. According to new data from economists at the Brookings Institute, a rich man born in 1920 could expect to live about five years longer than his less wealthy peers. Fast forward 20 years, and that life expectancy extension doubles to more than 12 years.

It's the same story for women. For women born in 1920, the life expectancy difference between the rich and the poor was 3.7 years. Twenty years later, that life expectancy difference has widened to 10.1 years.

So why are the rich seeing such a huge jump in life expectancy over their poorer peers? That's the big question that everyone wants to answer.

Most theories point to the drastically declining rates of smoking among the rich. The Centers for Disease Control and Prevention consider smoking the No. 1 cause of preventable death. But while smoking rates have declined for the rich, they have not changed much at all for the poor. Obesity and drugs have also been suggested as possible causes.

No matter the reason for the widening gap, one thing is clear: America's rich are getting richer (in prosperity and longevity) while the poor continue to lose ground.

When it comes to life expectancy, the rich are getting richer and the poor are losing ground
The life expectancy gap between America's richest and poorest is widening.