African American youth who report experiencing frequent discrimination during adolescence are at risk for developing heart disease, high blood pressure, diabetes, and stroke in later years, according to a new study.

The study also found that emotional support from parents and peers can protect African American youth from stress-related damage to their bodies and health.

The study, by researchers at the University of Georgia and Emory University, appears in the journal Child Development.

African American 20-year-olds who had reported frequent discrimination during adolescence experienced high levels of allostatic load - the biological wear and tear on the body due to exposure to repeated stress - placing them at risk for chronic diseases as they grow older, the study found.

"In the past, health professionals have believed that chronic diseases of aging such as heart disease originate in middle age, shortly before the appearance of symptoms, but our research shows that these illnesses originate much earlier, beginning in childhood and adolescence," notes Gene H. Brody, Regents' Professor and Director of the Center for Family Research at the University of Georgia, who led the study.

Researchers collected information from 331 African American youth living in rural Georgia in small towns where poverty is among the highest in the nation and unemployment rates are above the national average. The youth, part of the Strong African American Families Healthy Adolescent Project (SHAPE), were surveyed when they were 16, 17, 18, and 20 years old, to measure the racial discrimination they experienced and the emotional support they received from parents and peers. When the youth were 20, researchers determined their allostatic load by measuring blood pressure, body mass index, and levels of stress-related hormones in the urine. High allostatic load can lead to chronic diseases like high blood pressure, heart problems, diabetes, and stroke.

Parents also reported on how much emotional support they gave their sons and daughters by using a scale of 1 (not true at all) to 5 (very true) to respond to a number of statements (such as "If my child needs help with school or work, she/he can ask me about it").

The researchers found that although the stress with which African Americans live as they grow to young adulthood places them at risk for future illness, emotionally supportive relationships both inside and outside the family can short-circuit the progression to disease. African American adolescents who experienced greater racial discrimination and didn't receive emotional support from parents and peers had the highest levels of allostatic load of those studied. Adolescents who got emotional support didn't show the biological effects of racial discrimination.

"This is vital information for those who provide care to rural African American youth," says Brody. "The information is also important for public health professionals as they design interventions to prevent chronic diseases of aging among African Americans, and for policymakers as they seek to decrease race-based health discrepancies."