Stress plays key role in racial disparities in health

May 2, 2011 — Despite the widespread belief that racial differences in stress exist and that stress is linked to poor health, relatively few studies have investigated the topic. A new study conducted by Harvard School of Public Health (HSPH) researchers shows that African Americans and U.S-born Hispanics have higher levels of stress than whites and foreign-born Hispanics, and this stress helps to explain why these groups often have poorer health than whites.

The study was published online April 15, 2011, in special edition of The Du Bois Review: Social Science Research on Race.

“In the difficult economic times in which we live, this study underscores the importance of safety net programs – unemployment benefits, cash assistance, housing, childcare and transportation benefits to low-income working families – to promote the economic well-being and the health of families faced with high levels of stress,” said senior author David R. Williams, the Florence and Laura Norman Professor of Public Health at HSPH.

“Researchers had long believed that the wear and tear associated with stressful experiences contributes to racial differences in health and this study clearly confirms these suspicions,” said Michelle Sternthal, a research fellow at HSPH who was a postdoctoral student at the time of the study.

The research team, led by Sternthal, surveyed over 3,000 blacks, whites and Hispanics age 18 and above enrolled in the Chicago Community Adult Health Study and living in 343 Chicago neighborhoods. The sample included 1,240 non-Hispanic Blacks, 983 non-Hispanic whites, 802 Hispanics, and 80 persons from other racial groups. The team examined how stress related to four measures of health: poor self-rated health, symptoms of depression, chronic illnesses (e.g. heart trouble, cancer, high blood pressure) and functional limitations, such as difficulty stooping or carrying weights.

The researchers found that the amount of stress and type of stressors that an individual experiences matter and each additional stressor is associated with poor physical and mental health. Three types of stress – relationship, financial, and major life events, such as death of a loved one, a life-threatening illness, or unemployment – had the largest and most consistent negative effects.

“One of our striking findings is that both the levels of health and the levels of stress differed markedly for Hispanics by whether they were born in the U.S. or not,” said co-author Natalie Slopen, a doctoral student at HSPH at the time of the study and currently a postdoctoral fellow at Harvard’s Center for the Developing Child. U.S.-born Hispanics had levels of health and of stress similar to African Americans while foreign-born Hispanics were similar to whites on both health status and stress, the researchers found.

“The findings highlight the importance of all of us taking active steps to manage the stress in our lives,” Williams said.

Support for the study was provided by the National Institutes of Health’s Eunice Kennedy Shriver National Institute of Child Health & Human Development.

“Racial Disparities in Health: How Much Does Stress Really Matter?” Michelle J. Sternthal, Natalie Slopen, David R. WilliamsThe Du Bois Review: Social Science Research on Race, published online April 15, 2011.

Read the interview with David Williams

–Marge Dwyer