SOURCES: Kenneth Kochanek, M.A., statistician, National Center for Health Statistics, U.S. Centers for Disease Control and Prevention; Diane Sperling Lauderdale, Ph.D., professor, epidemiology, University of Chicago; Nov. 6, 2015, data brief, National Center for Health Statistics
FRIDAY, Nov. 6, 2015 (HealthDay News) -- Black Americans are catching up to whites in life expectancy -- largely due to declining rates of death from heart disease, cancer and HIV, a new federal government study finds.
Researchers said the study can only show what the trend is, and not the reasons for it. But it's likely that better access to medical treatments has played a role, they added.
Americans' life expectancy at birth has risen steadily over the last century, reaching an all-time high of 79 years in 2013. The life expectancy for black people, however, has always lagged behind that of whites, according to the researchers.
That gap still exists. But it is narrowing -- shrinking from a six-year difference in 1999 to a less than four-year difference in 2013, the study found.
And it appears that blacks are living longer because their death rates from heart disease, cancer, HIV and accidents are dropping, the new research found.
"Those causes of death are going down for everyone. But they're going down faster for African Americans," said lead researcher Kenneth Kochanek, of the U.S. Centers for Disease Control and Prevention's National Center for Health Statistics.
"The next step," Kochanek said, "is to figure out why. It could be access to health care, it could be lifestyle improvements. We can't tell from our data."
Diane Sperling Lauderdale, an epidemiologist at the University of Chicago, agreed that the reasons are unclear.
"You can't know if there's been a change in the number of people getting these diseases, or changes in the treatment," said Lauderdale, who studies health care inequalities.
But, she added, the past decade has seen advances in therapies for heart disease, various cancers and HIV. "So, I think it's likely that there's been improved access to those therapies [for blacks]," Lauderdale said.
There is research to support that notion. Last year, a study in the New England Journal of Medicine found that across U.S. hospitals, racial disparities in access to recommended treatments narrowed or disappeared between 2005 and 2010.
For example, many more minorities were getting angioplasty within 90 minutes of arriving at the hospital with heart attack symptoms.
For the current study, the CDC team used death certificate data to track national trends in mortality between 1999 and 2013.
The researchers found that for black people, life expectancy at birth rose from age 71 in 1999, to 75.5 by 2013. By comparison, white peoples' life expectancy increased from age 77 to 79.
When the researchers dug deeper into causes of death, they found that black men were seeing larger declines in deaths from HIV, cancer, heart disease and accidental injuries, versus white men. Among black women, deaths from heart disease, cancer and HIV dropped at a faster rate.
The decline in heart disease deaths was the single biggest contributor to improved life expectancy for black people, and especially for black women.
"That was really striking," Kochanek said. "Everyone knows that heart disease deaths have been going down in the U.S. But it looks like there's been a big impact for African Americans."
The news was not all good, however. Black people saw faster increases in rates of death from certain other diseases -- including Alzheimer's disease, aortic aneurysm, high blood pressure and complications related to pregnancy, the study found.
Lauderdale noted another limitation of the study -- it included deaths at any age. So it's not clear whether black people of all ages, or only certain age groups, are seeing improvements, she said.
The U.S. National Library of Medicine has more on health disparities.