Can racism lower life expectancy? A study in the February 2014 issue of the American Journal of Preventive Medicine found that racism may expedite aging in African American men who internalize it.

Researchers monitored chromosome caps, or telomeres, that can indicate risk of early death and disease based on the cap's length, which shortens over time. The shorter the caps, the greater risk of diabetes, dementia, stroke and heart disease.

African American men reported levels of racism that they experienced in housing, work, and public environments as well as day-to-day interactions. The men also took the Black-White Implicit Association Test to measure personal racial bias. 

Men who both experienced racism and held a personal bias against their race were found to have shorter caps than those without racial bias, despite the amount of discrimination that they experienced.

The study's lead researcher, Dr. David Chae, explained that men with positive views of their racial group may be less affected by discrimination than those with negative views. 

"Those who have internalized an anti-black bias may be less able to cope with racist experiences, which may result in greater stress and shorter telomeres," Chae explained in a University of Maryland article.

The average African American has a lower life expectancy than the average white American with a difference of four years, according to the Centers for Disease Control and Prevention. The study led by University of Maryland is the first to link racism and aging.