Although black Americans have had a significant increase in life expectancy, most of them die four years earlier than white Americans, according to health officials.

According to the U.S. Centers for Disease Control and Prevention, this gap is due to the higher death rates from cancer, diabetes, heart disease, murder and stroke. The increase for life expectancy in black population is faster than those in white population. Back in 1970 it was 7.6 years, and in 2010 it was only 3.8 years. The rate of improvement in life expectancy for blacks is 17 percent and only 10 percent for whites.

Stuart Jay Olshansky, a professor in the School of Public Health at the University of Illinois, in Chicago, conducted a study that examined the differences by level of education.

“This report confirms two things we know. One, that black life expectancy lags behind white life expectancy by a considerable margin. Two, that the main reasons for the gap are preventable,” said Sam Harper, from the department of epidemiology, biostatistics & occupational health at McGill University in Hamilton, Canada.

The report also found that life expectancy for black men was 4.7 years less than for white men and the life expectancy for black women was 3.3 years less than white women. Life expectancy for whites went from 71.7 years old in 1970 to 78.9 years old in 2010, while the life expectancy for blacks went from 64.1 years old to 75.1 years old during that same period.

Reducing the major risk factors for heart disease that disproportionately affect black Americans, and making certain that blacks are benefiting from improvements in medical treatments for cancer and heart disease is key factor to reducing the death rates of black Americans.