It’s well known that people from different parts of the world vary in their susceptibility to developing infections and diseases. Now, findings from two new studies, recently published in the journal Cell, suggest that certain genes in people of African descent may predispose them to mount a stronger immune response to infection that also creates a greater risk they’ll develop autoimmune diseases compared with people of European descent, UPI reports.

For the first study, researchers at several U.S. universities observed the immune response of white blood cells from 175 Americans, 80 of whom were of African descent, after they infected these cells with listeria and salmonella bacteria.

After 24 hours of infection, researchers noted that white blood cells from African Americans killed the bacteria three times faster than those of people descended from other population groups. Later, a second study by French researchers of white blood cells drawn from 200 more people of either European or African ancestry came to the same conclusion.

“The immune system of African Americans responds differently, but we cannot conclude it is better, since a stronger immune response also has negative effects,” said Luis Barreiro, MD, PhD, an assistant professor at the University of Montreal’s Department of Pediatrics and a senior researcher at the Sainte-Justine University Hospital Center in Montreal, where the first study was conducted.

An immune response triggers inflammation to get rid of infection in the body. But too much of this biological defense can cause high blood pressure, damage organs such as the heart and liver and increase a person’s susceptibility to autoimmune illnesses, such as lupus and Crohn’s disease. Scientists believe this might be why African Americans suffer disproportionately from these conditions compared with white Americans.

But researchers also think this new genetic information could pave the way for better treatments to reduce chronic health risks for African Americans.

To learn more about racial differences in chronic health risks, click here.