Black men are more likely to die of lung cancer than white men. They have a nine percent higher risk of having a heart attack and a 25 percent increased chance of getting cancer.
"Racism can be considered the 'missing variable' in research on black-white differences in health," George Davey Smith, professor of social medicine at Bristol University in southwest England, said in a study published in the Lancet medical journal Friday.
He said socio-economic position was the major contributor to the death rate disparity, but racism could underpin differences in medical care and health-related behavior and influence opportunities to maintain and improve health.
"Racism needs to be investigated and combated at individual, institutional and societal levels," he said.
Davey Smith and researchers at the University of Minnesota and Northwestern University Medical School in Chicago conducted one of the few studies into factors affecting death rates for people of different ethnic origins.
"As a consequence of it (racism) people get off to a bad start, with bad exposure to different things that harm their health, and later in life they don't have the care for it as they should have if it didn't exist," James Neaton of the University of Minnesota told Reuters.
Income and socio-economic status had the greatest effect on risks of death and racism had a direct bearing on both of them.
Lower incomes meant poorer housing, lower occupational status and less purchasing power for food, clothing and other necessities.
The researchers studied information on 20,224 black men and 300,685 white men obtained from the 1980 U.S. census or a screening done for a Multiple Risk Factor Intervention Trial (MRFIT) that took place in 1973-75.
The ages of the men, where they lived, how much they earned and information on smoking, blood pressure, cholesterol, heart attacks and diabetes were included.
After noting the cause of death for the men who had died by 1990, the researchers calculated the risks from various causes.
Blacks had an overall risk of death just under 50 percent higher than whites. After adjustment for risk factors such as blood pressure, cholesterol, smoking, diabetes and heart attack, the risk was 40 percent higher.
Death from heart and renal disease, stroke, lung and prostate cancer and homicide were higher for blacks, while more white men committed suicide or died from melanoma.
The researchers said the consistency of the differences in death rate between the two racial groups across the 22 areas of the United States covered by the MRFIT survey suggested their findings are "robust and generalizable."
Although the study reflected social conditins in the 1970s, Neaton said the higher proportion of blacks in the United States with the HIV virus and AIDS seemed to indicate the situation had not changed drastically in the last two decades.
"HIV certainly is not a statement that it has improved very much," Neaton added. "It has perhaps gotten better for access to care for chronic conditions like cancers and heart disease.
"I think probably there is a big problem with regard to environmental exposures, dietary differences and because of access to the right education and the setting in which you live."
The researchers called for further research into lifestyle, biological factors, effects of racism and socio-economic conditions so that the differences in death rates could be decreased.
"The major determinants of black-white differences in mortality are apparently socio-environmental, in the broadest sense, and efforts to decrease differences should be focused at this level," they said.
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