FRIDAY, Jan. 27 (HealthDay News) -- Discrimination can be a threat to health, according to a new study that included both blacks and whites.

The analysis of 2004 data from the ongoing U.S. Behavioral Risk Factor Surveillance System project found that about 18 percent of blacks and 4 percent of whites reported emotional and physical distress caused by discriminatory treatment.

"Discriminatory behavior very well may be a 'missing link' in the analysis of racial and ethnic health disparities. It's important to acknowledge and study its impact on long-term health," study author Jenifer Bratter, a sociologist at Rice University in Houston, said in a university news release.

The study's inclusion of people in both races "is important because we examine whether discrimination is equally harmful to the health status of black and white adults -- or whether experiencing discrimination is disproportionately harmful to either black or white adults," fellow author Bridget Gorman, also a sociologist at Rice University, said in the news release.

"For example, since, on average, black adults typically experience more health risks in their social and personal environment than white adults (including higher poverty and lower-quality medical insurance), they may be especially vulnerable to negative health effects as a result of racial discrimination," Gorman noted.

Along with finding that more blacks report poorer health due to discrimination, the researchers also determined that the harmful effects of discrimination do play a role in health disparities between blacks and whites.

And while discrimination can increase some of the economic-based health risks typically experienced by black adults, the situation is different for whites.

Regardless of social-class position, white adults who believe they've experienced workplace or health care discrimination report poorer health, the investigators found.

"A relatively small proportion of white adults report unfair treatment that is race-based, but those who do say their health status is harmed more than blacks who report the same experiences," Gorman said.

The study was published in a recent issue of the Journal of Health and Social Behavior.

More information

The U.S. Centers for Disease Control and Prevention has more about health disparities.