The life expectancy gap between African-Americans and whites in the U.S. has hit an all-time low.

A new report shows the racial gap in life expectancy rates declined by about a year for both men and women between 2003 and 2008.

The results showed the difference in life expectancy at birth between whites and African-Americans decreased from 6.5 to 5.4 years among men and 4.6 to 3.7 years among women.

"These racial inequalities among men and women in 2008 are the lowest ever recorded in the United States," write researcher Sam Harper, PhD, of McGill University, Montreal, Canada, and colleagues in the Journal of the American Medical Association.

"Understanding the causes of black-white differences in mortality has important consequences for interventions to reduce health inequalities," they write.

African-Americans in the U.S. have traditionally had significantly lower life expectancy rates compared with their white counterparts. Researchers say the results continue a trend first reported in 1993 that shows the racial gap in life expectancy is narrowing.
Racial Gap Narrowing

In the study, researchers used federal statistics to compare life expectancy rates among men and women between 2003 and 2008.

The results showed the average life expectancy at birth increased for both non-Hispanic white and African-American men, from 75.3 to 76.2 years and 68.8 to 70.8 years, respectively.

Similar gains were found among women. Life expectancy rates increased from 80.3 to 81.2 years for non-Hispanic white women and 75.7 to 77.5 years for African-American women.

Researchers say differences in heart disease, diabetes, homicide, HIV, and infant mortality rates remain the chief causes behind the racial gap in life expectancy rates.

"However, in contrast to 1993-2003, homicide has not played an important role in reducing black-white differences among men since 2003," write the researchers. "Rather, changes in unintentional injury deaths were a major reason, along with heart disease and HIV, for the narrowing gap among both men and women."

The study suggests a large increase in accidental poisoning deaths among whites has contributed to narrowing the racial gap in life expectancy.

Since 2003, the results show poisoning deaths have eclipsed motor vehicle crashes as the leading cause of injury death and have affected middle-aged white men more than any other group.