Overall, the heart disease mortality rate decreased by 28 percent between 2003 and 2015, and the cancer mortality rate dropped by 16 percent.
>> On AJC.com: Eat this meat twice a week to avoid heart attacks and strokes
However, upon further investigation, they discovered cancer deaths may be more on the rise in higher income counties. Heart disease deaths declined by 30 percent in high-income counties, while low-income counties experienced a 22 percent drop. A similar pattern was apparent for cancer deaths as the threat fell by 18 percent in high-income counties and by 11 percent in low-income ones.
“Data show that heart disease is more likely to be the leading cause of death in low-income counties,” the authors wrote. “Low-income counties have not experienced the same decrease in mortality rates as high-income counties, which suggests a later transition to cancer as the leading cause of death in low-income counties.”
>> Read more trending news
They also noted patterns among racial and ethnic groups. Cancer replaced heart disease as the leading cause of death for Asian-Americans, Hispanics and whites. That was not the case for American Indians/Alaska Natives or blacks.
While the mechanisms behind the shifts in mortality rates are unclear, the scientists believe differences in smoking, obesity and diabetes trends between high and low income groups could be factors.
As they continue their research, they are encouraging individuals to undergo recommended cancer screenings and practice healthy lifestyles.
>> On AJC.com: You may be able to better avoid heart attacks with this common snack, study says
Read more about the findings here.