America's poorest live about five fewer years than the richest, according to a new study.
Rice University and University of Colorado at Boulder researchers also found that the average life expectancy in the United States is still trailing behind that of other nations at around 78, including Japan (83.91 years), Macau (84.43) and Monaco (89.68).
In addition, researchers found that the greatest "growth spurts" in U.S. life expectancy occurred between the 1930s and the 1950s, and during the 1960s.
"Since that time, gains in life expectancy have flattened out," study researcher Justin Denney, an associate sociology professor at Rice University, said in a statement.
Specifically, life expectancy in 1930 was 59.85 in the U.S., while it was 77.1 in 2000.
"During periods of expansion in length of life, a similar expansion has occurred between more and less advantaged groups -- the rich get richer, the poor get poorer, inequality grows and life expectancy is dramatically impacted," Denney said. "And despite disproportionate spending on health care, life expectancy in the U.S. continues to fall down the ladder of international rankings of length of life. It goes to show that prosperity doesn’t necessarily equal long-term health."
The study will be published in the journal Social Science Quarterly. It included life expectancy data from 1930 to 2000, as well as forecast data up to 2055.
A similar study was also done in the U.K., results of which were published earlier this year -- it showed that wealthy people there also live longer than their poor counterparts.
Specifically, that study showed that those who work professional and/or higher managerial jobs live about three years longer than those who do more "routine tasks," HuffPost Business reported.
Recently, a study on county life expectancies from the Institute for Health Metrics and Evaluation showed that women's life expectancies are improving at a slower rate than men's across the country. Between 1989 and 2009, the researchers found that men's life expectancy increased by an average of 4.6 years. But women's life expectancy only increased by an average of 2.7 years.
Now, in 2009, the county calculations showed that men's life expectancy ranges from 66.1 to 81.6 years and the women's life expectancy ranges from 73.5 to 86, according to the study.
Click through the slideshow check out the average life expectancy for men and women by state, calculated as the average of the county life expectancies: