A study published in the American Journal of Public Health concluded that the well-documented prevalence of hypertension among African Americans is largely caused by racial discrimination. The article, "Racial Discrimination and Blood Pressure," was written by Nancy Krieger of the Harvard School of Public Health, and its conclusions were reported in newspapers such as the New York Times, the Washington Post and on news broadcasts nationwide, thanks to a strategically timed press release faxed to various media outlets by the American Public Health Association's public-relations department.

The study was based on blood pressure readings taken from 831 black men and 1,143 black women between the ages of 25 and 37. The participants were asked questions designed to categorize them by income, occupation, education, and marital status. Factors known to raise blood pressure, such as obesity and smoking, were identified and weighted to eliminate them as variables. Participants were also asked if they experienced racism in any of seven situations: "at school," "getting a job," "at work," "getting housing," "getting medical care," "on the street or in a public setting," and "from the police or in the courts."

Though Krieger concluded that the stress of experiencing racism is a significant cause of high blood pressure among African Americans, some of her results did not fit that thesis. For example, professional-class blacks had significantly lower blood pressure than working-class blacks, even though the study's data showed that professional-class blacks claim to encounter more racism than their blue-collar counterparts. But according to Krieger it doesn't drive their blood pressure up as much because of "their greater social and economic resources and, thus, perhaps greater willingness to name and challenge discriminatory treatment."

Krieger also used her interpretive skills to explain other anomalies as well. While the average blood pressure of those reporting multiple instances of racism was higher than that of those who said they experienced less racism, the highest average blood pressure was found in working-class black men who reported no discrimination at all. Krieger explained the deficiency thus: "Individuals who have experienced but feel unable to challenge discrimination may find it painful to admit that they have experienced discrimination, either to themselves or another person."

The study's data also showed that professional-class black men who report no discrimination suffer less hypertension than professional-class black men who do. While this fits with Krieger's overall thesis, it does not square with her previous contention that those reporting no discrimination were effectively in denial and presumably suffering even greater discrimination. As a result, Krieger asserted that because of their greater resources, professional-class black men do not lie to themselves about racism, but instead confront it when it happens. They can thus be trusted to report their experiences accurately, whereas working-class black men cannot.

Also, working-class black women who presumably accept discrimination and keep it to themselves have higher blood pressure than those who talk about it, but working-class black men who talk about it have higher blood pressure than those who remain silent. Krieger explains: "These patterns may reflect gender differences in how working-class black women and men respond to and talk about discrimination."

Krieger's previous articles on related subjects include "The influence of social class, race, and gender on the etiology of hypertension among women in the United States" and "Racism, sexism, and social class: implications for studies of health, disease, and well-being."

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