African-American men exposed to high levels of racial discrimination and strong internal anti-black attitudes age faster, according to a University of Maryland study.

"We examined a biomarker of systemic aging, known as leukocyte telomere length," Dr. David H. Chae, assistant professor of epidemiology at the University of Maryland School of Public Health and the study's lead investigator, said in a statement. "We found that the African American men who experienced greater racial discrimination and who displayed a stronger bias against their own racial group had the shortest telomeres of those studied."

Normally, telomeres lose about 50 to 100 base pairs every year, but its length could shorten faster due to elevated psycho-social and physiological stress. Shorter telomere length causes premature deaths and chronic diseases such as diabetes, dementia, stroke and heart disease.

For the study, researchers asked 92 African-American men, aged between 30 and 50, about their discrimination history in their personal and professional lives. The participants were also asked to undertake the Black-White Implicit Association Test. The test measures the participant's attitudes and beliefs towards race groups. 

They found that respondents, who experienced greater amounts of racism and scored high marks in the test, had shorter telomeres.

"African-American men who have more positive views of their racial group may be buffered from the negative impact of racial discrimination," Chae said. "In contrast, 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."

Researchers said that this is the first study that has established a link between racism-related experiences and aging process at the biological, cellular level.

The study has been published in American Journal of Preventive Medicine.