WEDNESDAY, March 16 (HealthDay News) -- The death rate in the United States reached an all-time low in 2009, the 10th straight year of decline, dropping 2.3 percent from 2008, federal health officials report.

"There is basically good news," said lead author Kenneth Kochanek, a statistician at the U.S. Centers for Disease Control and Prevention's National Center for Health Statistics.

"Ten of the major causes of death decreased significantly," he said. "You have life expectancy going up, you have infant mortality going down," he added.

Kochanek cautioned that this is preliminary data, and the CDC has not looked at the reasons for these trends. The final data, which should be available this summer, may shed some light on the findings, he noted.

Behavioral changes, particularly the decline in smoking, are partly responsible for the improvements, one expert says.

The report shows a drop from 758.7 deaths per 100,000 people in 2008 to 741 per 100,000 people in 2009. In all, 2,436,682 deaths were reported in 2009.

Overall U.S. life expectancy rose slightly from 78 years to 78.2 years between 2008 and 2009. Men's life expectancy increased to 75.7 years and women's to 80.6 years, the researchers found.

However, life expectancy for blacks remained unchanged -- 70.9 years for men and 77.4 years for women. The disparity between whites and blacks is now 4.3 years, representing a 0.2 percent increase from 2008 to 2009, the report found.

"We are not really sure why life expectancy did not go up for blacks," Kochanek said. "That's one of those things we have to look at with the final data."

Deaths fell in 10 of the 15 leading causes of death. Heart disease dropped 3.7 percent, cancer fell 1.1 percent, and stroke declined 4.2 percent. Deaths from Alzheimer's disease, diabetes, chronic lower respiratory diseases and accidents all declined 4.1 percent. Deaths from flu and pneumonia fell 4.7 percent, and deaths from septicemia, a bacterial infection, decreased 1.8 percent.

Deaths from homicides fell 6.8 percent, but suicides increased from 35,933 in 2008 to 36,547 in 2009. Other than suicide, which overtook septicemia as the 10th leading cause of death, the ranking of the leading causes of death was unchanged from 2008 to 2009, the researchers noted.

Infant mortality hit a record low in 2009, falling from 6.59 deaths per 1,000 births in 2008 to 6.42, representing a 2.6 percent decrease, according to the report.

The leading causes of infant deaths are birth defects, preterm birth, low birth weight and sudden infant death syndrome, the researchers explained.

These data represent 96 percent of death certificates reported to the National Vital Statistics System from all states, the District of Columbia and U.S. territories.

Kochanek noted that the United States is still behind other countries in life expectancy, infant mortality and death rates.

"But we are getting better," he said.

Commenting on the report, Dr. Laurence Gardner, a professor of medicine at the University of Miami Miller School of Medicine, said these trends most likely reflect the widespread decrease in smoking.

"And maybe the medical profession gets some credit here," he said. "I don't think we should beat our chests too strongly, but the evidence is beginning to hint at better management of chronic illness, which would explain why people are living longer with a confirmed diagnosis."

As for the disparity in life expectancy between blacks and whites, Gardner offered three possible explanations.

"There may be more violence, a real issue about disparity in access to health care and possible issues with the data," he said.

Compared with other countries, Gardner doesn't think the United States has made all that much progress.

"I don't think this puts the U.S. health care system at the top of the world any more than it was," Gardner said.

More information

For more about life expectancy, visit the U.S. Centers for Disease Control and Prevention.