<p class="lead" id="first">People who live in communities with higher levels of racial prejudice have worse health outcomes, including more heart disease and mental health problems and higher overall mortality rates, according to research published by the American Psychological Association.</p><p>The researchers conducted a systematic review of fourteen papers that used data gathered from Google, Twitter and other big-data sources to look at how prejudice and health are intertwined in communities across the United States.</p><p>"Racism is gaining recognition as a fundamental driver of health inequities," said lead study author Eli Michaels, MPH, a doctoral candidate at the University of California, Berkeley. "Leveraging big data to capture area-level racial prejudice is one innovative approach to measuring the overall racial climate in which people live, work, play and pray. The studies included in this review revealed that living in an area with high levels of racial prejudice may harm health and widen racial health inequities."</p><p>The research was published in the journal <em>Health Psychology</em>.</p><p>The studies in the review used a variety of sources to measure community-level racial prejudice and included tens of millions of data points from large-scale surveys, internet searches and social media. Three studies analyzed data from Google Trends on how often users' searches included a racial slur. Four studies analyzed data from Twitter on tweets that included negative sentiments toward people of color. Three studies used data from the General Social Survey, a nationally representative survey of social and political attitudes in the United States. And four studies used data from Project Implicit, an online tool that assesses people's implicit biases toward various groups. All of the data were coded by geographic area.</p><p>The studies examined how these different indicators of area-level racial prejudice correlated with health outcomes among individuals living in those areas, including mortality rates, adverse birth outcomes for mothers and infants, cardiovascular outcomes, mental health and overall self-rated health. All of the studies found an association between communities' levels of racial prejudice and adverse health outcomes for the people of color who lived there; four studies also showed a similar association among white residents (two studies showed a smaller but still harmful effect on whites compared with people of color).</p><p>"The majority of research on racial discrimination and health to date has focused on experiences at the individual level," said Amani M. Allen, PhD, MPH, a professor of community health sciences and epidemiology at the University of California Berkeley School of Public Health and senior author of the study.</p><p>"The emerging body of work examined in this review is an important step in going above the level of the individual to capture the context of place and how it may impact the health of people living in those places," Allen said. "As we see from this review, living in an environment with an overall climate that is prejudiced against people of color is not only bad for racially marginalized groups, but for everyone. Area-level racial prejudice is a social determinant of population health."</p><p>There are various theories as to how community racial prejudice may harm health, according to the researchers. One is that at an individual level, living in a community with more prejudice could increase the number of prejudiced interactions that a person experiences, causing harmful stress. At the community level, more racial prejudice may erode social capital -- defined as "the norms of reciprocity, trust and social obligation" in a community -- leading to less social and emotional support to buffer stressful life events and less political support for policies and programs that could enhance the health and welfare of all community members.</p><p>More research is needed to disentangle these various factors that may tie community-level racial prejudice to adverse health outcomes for communities overall and for people of color in particular, according to the researchers.</p><p>"Because racism is multidimensional, dismantling it and its effects on health will require multidimensional solutions," Michaels said. "Research identifying the root causes of, and testing interventions to shift, our collective prejudice is an urgent priority."</p>