Race and health

Race and health research is mostly from the United States. It has found both current and historical racial differences in the frequency, treatments, and availability of treatments for several diseases. This can add up to significant group differences in variables such as life expectancy. Many explanations for such differences have been argued, including socioeconomic factors (e.g., education, employment, and income), lifestyle behaviors (e.g., physical activity and alcohol intake), social environment (e.g., educational and economic opportunities, racial/ethnic discrimination, and neighborhood and work conditions), and access to preventive health-care services (e.g., cancer screening and vaccination) as well as to treatment (through lack of insurance, lack of hospitals in certain areas, etc.), among other environmental differences. Some diseases may also be influenced by genes which differ in frequency between races, although the significance in clinical medicine of race categories as a proxy for exact genotypes of individuals has been questioned.

Race and racism
There is considerable debate about the usefulness of racial categories in studies of health. Likewise, the effects of racism on social mobility, segregation and psychological well-being being of ethnic minorities is an emerging topic of study in health research. David Williams writes that because race is an unscientific, societally constructed taxonomy, racial or ethnic variations in health status result primarily from variations among races in exposure or vulnerability to behavioral, psychosocial, material, and environmental risk factors and resources. Although race has only limited biological significance, the concept of race is socially meaningful in the study of health. Trevor A. Sheldon and Hilda Parker write that thought and care is needed before data are routinely categorized by race or before race is included as a variable in medical research. They write that the tendency to collect routine ethnic data and include ethnic variables in an ad hoc and uncritical way in the United Kingdom and other countries may help transform minorities into mere statistical categories and produce data and findings which reinforce stereotypes. David Williams writes that terms used for race are seldom defined and race is frequently employed in a routine and uncritical manner to represent ill-defined social and cultural factors. A. H. Goodman writes that using race as a proxy for genetic differences limits understandings of the complex interactions among political-economic processes, lived experiences, and human biologies. Thomas A. LaVeist writes that while no credible scientist believes that race has any biological or genetic basis, it does have profound social meaning, rooted in history but with contemporary consequences. Racial status is a risk marker for exposure to racism, which may be a primary etiological factor in race differences in morbidity and mortality.

In biomedical research conducted in the U.S., the 2000 US census definition of race is often applied. This grouping recognizes five races: black or African American, white, Asian, native Hawaiian or other Pacific Islander, and American Indian or Alaska native. However, this definition is inconsistently applied across the range of studies that address race as a medical factor, making assessment of the utility of racial categorization in medicine more difficult.

From the perspective of genetics, human population structure is the result of patterns of mating. Francis Collins writes that increasing scientific evidence indicates that genetic variation can be used to make a reasonably accurate prediction of geographic origins of an individual, at least if that individual's grandparents all came from the same part of the world. Migration between countries in the last two centuries, with consequent racial admixture has caused some to question the significance of this notion of race to medicine.

In multiracial societies such as the United States, racial groups differ greatly in regard to social and cultural correlates such as economic status and access to healthcare. These factors are believed to explain most if not all of the differential health care outcomes among races. An open area of investigation is whether genetic differences still show evidence of presences after social and cultural correlates are taken into account.

Health
Health is measured through variable such as life expectancy, and incidence of diseases. The undeniable existence of health disparities indicate that there is a correlation between self-identified race or ethnicity and health or disease in some cases. But the relationship among these factors is complex and poorly understood. Some researchers suggest that to unravel the real causes of health disparities, research must move beyond weakly correlated variables, such as self-identified race or ethnicity, towards an understanding of the more proximate environmental and genetic factors. People of German backgrounds tend to suffer from hypertension and other types of anxiety disorders.

Health disparities
Health disparities refer to gaps in the quality of health and health care across racial and ethnic groups. The Health Resources and Services Administration defines health disparities as "population-specific differences in the presence of disease, health outcomes, or access to health care."

In the United States, health disparities are well documented in minority populations such as African Americans, Native Americans, Asian Americans, and Latinos. When compared to whites, these minority groups have higher incidence of chronic diseases, higher mortality, and poorer health outcomes. Among the disease-specific examples of racial and ethnic disparities in the United States is the cancer incidence rate among African Americans, which is 10 % higher than among whites. In addition, adult African Americans and Latinos have approximately twice the risk as whites of developing diabetes. Minorities also have higher rates of cardiovascular disease, HIV/AIDS, and infant mortality than whites.

In the United States
The twentieth century witnessed a great expansion of the upper bounds of the human life span. At the beginning of the century, average life expectancy in the United States was 47 years. By century's end, the average life expectancy had risen to over 70 years, and it was not unusual for Americans to exceed 80 years of age. However, although longevity in the U.S. population has increased substantially, race disparities in longevity have been persistent. African American life expectancy at birth is persistently five to seven years lower than whites. Princeton Survey Research Associates found that in 1999 most whites were unaware that race and ethnicity may affect the quality and ease of access to health care. U.S. Latinos have higher rates of death from diabetes, liver disease, and infectious diseases than do non-Latinos (Vega and Amaro 1994). Native Americans suffer from higher rates of diabetes, tuberculosis, pneumonia, influenza, and alcoholism than does the rest of the U.S. population (Mahoney and Michalek 1998). European Americans die more often from heart disease and cancer than do Native Americans, Asian Americans, or Hispanics (Hummer et al. 2004). In the United States, African Americans have higher rates of mortality than does any other racial or ethnic group for 8 of the top 10 causes of death (Hummer et al. 2004).

The vast majority of studies focus on the black-white contrast, but a rapidly growing literature describes variations in health status among America's increasingly diverse racial populations. Where people live, combined with race and income, play a huge role in whether they may die young. A 2001 study found large racial differences exist in healthy life expectancy at lower levels of education. A study by Jack M. Guralnik, Kenneth C. Land, Dan Blazer, Gerda G. Fillenbaum, and Laurence G. Branch found that education had a substantially stronger relation to total life expectancy and active life expectancy than did race. Still, sixty-five-year-old black men had a lower total life expectancy (11.4 years) and active life expectancy (10 years) than white men (total life expectancy, 12.6 years; active life expectancy, 11.2 years) The differences were reduced when the data were controlled for education.

History
Disparities in health and life span among blacks and whites in the US have existed since the period of slavery. David R. Williams and Chiquita Collins write that, although racial taxonomies are socially constructed and arbitrary, race is still one of the major bases of division in American life. Throughout US history racial disparities in health have been pervasive. Clayton and Byrd write that there have been two periods of health reform specifically addressing the correction of race-based health disparities. The first period (1865-1872) was linked to Freedmen's Bureau legislation and the second (1965-1975) was a part of the Black Civil Rights Movement. Both had dramatic and positive effects on black health status and outcome, but were discontinued. Although African-American health status and outcome is slowly improving, black health has generally stagnated or deteriorated compared to whites since 1980.

Demographic changes can have broad impacts on the health of ethnic groups. Cities in the United States have undergone major social transitions during the 1970s 1980s and 1990s. Notable factors in these shifts have been sustained rates of black poverty and intensified racial segregation, often as a result of redlining. Indications of the effect of these social forces on black-white differentials in health status have begun to surface in the research literature. Race has played a decisive role race in shaping systems of medical care in the United States. The divided health system persists, in spite of federal efforts to end segregation, health care remains, at best widely segregated both exacerbating and distorting racial disparities.

Racism
Racial differences in health often persist even at "equivalent" levels of SES. Individual and institutional discrimination, along with the stigma of inferiority, can adversely affect health. Racism can also directly affect health in multiple ways. Residence in poor neighborhoods, racial bias in medical care, the stress of experiences of discrimination and the acceptance of the societal stigma of inferiority can have deleterious consequences for health. Using The Schedule of Racist Events (SRE), an 18-item self-report inventory that assesses the frequency of racist discrimination. Hope Landrine and Elizabeth A. Klonoff found that racist discrimination is rampant in the lives of African Americans and is strongly related to psychiatric symptoms. A study on racist events in the lives of African American women found that lifetime racism was positively related to lifetime history of both physical disease and frequency of recent common colds. These relationships were largely unaccounted for by other variables. Demographic variables such as income and education were not related to experiences of racism. The results suggest that racism can be detrimental to African American's well being. The physiological stress caused by racism has been documented in studies by Claude Steele, Joshua Aronson, and Steven Spencer on what they term "stereotype threat." Kennedy et al found that both measures of collective disrespect were strongly correlated with black mortality (r = 0.53 to 0.56), as well as with white mortality (r = 0.48 to 0.54). A 1 percent increase in the prevalence of those who believed that blacks lacked innate ability was associated with an increase in age-adjusted black mortality rate of 359.8 per 100,000 (95% confidence interval: 187.5 to 532.1 deaths per 100,000). These data suggest that racism, measured as an ecologic characteristic, is associated with higher mortality in both blacks and whites.

Inequalities in health care
There is a great deal of research into inequalities in health care. In some cases these inequalities are a result of income and a lack of health insurance a barrier to receiving services. Almost two-thirds (62 percent) of Hispanic adults aged 19 to 64 (15 million people) were uninsured at some point during the past year, a rate more than triple that of working-age white adults (20 percent). One-third of working-age black adults (more than 6 million people) were also uninsured or experienced a gap in coverage during the year. Blacks had the most problems with medical debt, with 61 percent of uninsured black adults reporting medical bill or debt problems, vs. 56 percent of whites and 35 percent of Hispanics. Compared with white women, black women are twice as likely and Hispanic women are nearly three times as likely to be uninsured.

In other cases inequalities in health care reflect a systemic bias in the way medical procedures and treatments are prescribed for different ethnic groups. Raj Bhopal writes that the history of racism in science and medicine shows that people and institutions behave according to the ethos of their times and warns of dangers to avoid in the future. Nancy Krieger contended that much modern research supported the assumptions needed to justify racism. Racism underlies unexplained inequities in health care, including treatment for heart disease, renal failure, bladder cancer, and pneumonia. Raj Bhopal writes that these inequalities have been documented in numerous studies. The consistent and repeated findings that black Americans receive less health care than white Americans—particularly where this involves expensive new technology—is an indictment of American health care.

The infant mortality rate for African Americans is approximately twice the rate for European Americans, but, in a study that looked at members of these two groups who belonged to the military and received care through the same medical system, their infant mortality rates were essentially equivalent (Rawlings and Weir 1992). Recent immigrants to the United States from Mexico have better indicators on some measures of health than do Mexican Americans who are more assimilated into American culture (Franzini et al. 2001). Diabetes and obesity are more common among Native Americans living on U.S. reservations than among those living outside reservations (Cooper et al. 1997).

Krieger writes that given growing appreciation of how race is a social, not biological, construct, some epidemiologists are proposing that studies omit data on "race" and instead collect better socioeconomic data. Krieger writes that this suggestion ignores a growing body of evidence on how noneconomic as well as economic aspects of racial discrimination are embodied and harm health across the lifecourse. Gilbert C. Gee's study A Multilevel Analysis of the Relationship Between Institutional and Individual Racial Discrimination and Health Status found that individual (self-perceived) and institutional (segregation and redlining) racial discrimination is associated with poor health status among members of an ethnic group.

Cardiovascular disease
In a summary of recent studies Jules P. Harrell, Sadiki Hall, and James Taliaferro describe how a growing body of research has explored the impact of encounters with racism or discrimination on physiological activity. Several of the studies suggest that higher blood pressure levels are associated with the tendency not to recall or report occurrences identified as racist and discriminatory. In other words, suppression of awareness of instances of racism has a direct impact on the blood pressure of the person experiencing the racist event. Investigators have reported that physiological arousal is associated with laboratory analogs of ethnic discrimination and mistreatment. Racism may lead to a higher incidence of cardiovascular disease in African Americans in three ways:


 * 1) Institutional racism leads to limited opportunities for socioeconomic mobility, differential access to goods and resources, and poor living conditions.
 * 2) Perceived racism acts as a stressor and can induce psychophysiological reactions that negatively affect cardiovascular health.
 * 3) Negative self-evaluations and accepting negative cultural stereotypes as true (internalized racism) can have deleterious effects on cardiovascular health.

Fear of racism
While actual racism continues to have adverse impacts on health, fear of racism, due to historical precedents, can also cause some minority populations to avoid seeking medical help. For example, a 2003 study showed that a large percentage of respondents perceived discrimination targeted at African American women in the area of reproductive health. Likewise beliefs such as "The government is trying to limit the Black population by encouraging the use of condoms" have also been studied as possible explanations for the different attitudes of whites and blacks towards efforts to prevent the spread of HIV/AIDS.

Infamous examples of real racism in the past, such as the Tuskegee Syphilis Study (1932-1972), have injured the level of trust in the Black community towards public health efforts. The Tuskegee study deliberately left Black men diagnosed with syphilis untreated for 40 years. It was the longest nontherapeutic experiment on human beings in medical history. The AIDS epidemic has exposed the Tuskegee study as a historical marker for the legitimate discontent of Blacks with the public health system. The false belief that AIDS is a form of genocide is rooted in recent experiences of real racism. These theories range from the belief that the government promotes drug abuse in Black communities to the belief that HIV is a manmade weapon of racial warfare. Researchers in public health hope that open and honest conversations about racism in the past can help rebuild trust and improve the health of people in these communities.

Segregation
Some researchers suggest that racial segregation may lead to disparities in health and mortality. Thomas LaVeis (1989; 1993) tested the hypothesis that segregation would aid in explaining race differences in infant mortality rates across cities. Analyzing 176 large and midsized cities, LaVeist found support for the hypothesis. Since LaVeist's studies, segregation has received increased attention as a determinant of race disparities in mortality. Studies have shown that mortality rates for male and female African Americans are lower in areas with lower levels of residential segregation. Mortality for male and female Whites was not associated in either direction with residential segregation.

In a study by Sharon A. Jackson, Roger T. Anderson, Norman J. Johnson and Paul D. Sorlie the researchers found that, after adjustment for family income, mortality risk increased with increasing minority residential segregation among Blacks aged 25 to 44 years and non-Blacks aged 45 to 64 years. In most age/race/gender groups, the highest and lowest mortality risks occurred in the highest and lowest categories of residential segregation, respectively. These results suggest that minority residential segregation may influence mortality risk and underscore the traditional emphasis on the social underpinnings of disease and death. Rates of heart disease among African Americans are associated with the segregation patterns in the neighborhoods where they live (Fang et al. 1998). Stephanie A. Bond Huie writes that neighborhoods affect health and mortality outcomes primarily in an indirect fashion through environmental factors such as smoking, diet, exercise, stress, and access to health insurance and medical providers. Moreover, segregation strongly influences premature mortality in the US.

Socioeconomic factors
A study by Christopher Murray contends the differences are so stark it is "as if there are eight separate Americas instead of one." Leading the nation in longevity are Asian-American women who live in Bergen County, N.J., and typically reach their 91st birthdays, concluded Murray’s county-by-county analysis. On the opposite extreme are American Indian men in swaths of South Dakota, who die around 58.


 * Asian-Americans, average per capita income of $21,566, have a life expectancy of 84.9 years.
 * Northland low-income rural Whites, $17,758, 79 years.
 * Middle America (mostly White), $24,640, 77.9 years.
 * Low-income Whites in Appalachia, Mississippi Valley, $16,390, 75 years.
 * Western American Indians, $10,029, 72.7 years.
 * Black Middle America, $15,412, 72.9 years.
 * Southern low-income rural Blacks, $10,463, 71.2 years.
 * High-risk urban Blacks, $14,800, 71.1 years.

The risks for many diseases are elevated for socially, economically, and politically disadvantaged groups in the United States, suggesting that socioeconomic inequities are the root causes of most of the differences (Cooper et al. 2003; Cooper 2004).

Trends
Based on data for 1945 to 1999, forecasts for relative black:white age-adjusted, all-cause mortality and white:black life expectancy at birth showed trends toward increasing disparities. From 1980 to 1998, average numbers of excess deaths per day among American blacks relative to whites increased by 20%. David Williams writes that higher disease rates for blacks (or African Americans) compared to whites are pervasive and persistent over time, with the racial gap in mortality widening in recent years for multiple causes of death.

Environmental racism
Environmental racism is a form of racial discrimination where race-based differential enforcement of environmental rules and regulations; the intentional or unintentional targeting of minority communities for the siting of polluting industries such as toxic waste disposal; and the exclusion of people of color or lack thereof from public and private boards, commissions, and regulatory bodies results in greater exposure to pollution. RD Bullard writes that a growing body of evidence reveals that people of color and low-income persons have borne greater environmental and health risks than the society at large in their neighbourhoods, workplaces and playgrounds.

Race and genetic biomedical research
The role of race in biomedicine is actively debated among biomedical researchers. The primary impetus for considering race in biomedical research is the possibility of improving the prevention and treatment of diseases. Many previous studies have observed that disease susceptibility and environmental responses vary by race. Thus, some researchers believe that race may be an informative category for biomedical research. Other researchers believe that racial categories have no valid biomedical applications, and may be socially harmful (Jackson, 2004).

The role of race in biomedicine is actively debated among biomedical researchers.

Several questions are considered:


 * can the concept of "race" be considered valid?
 * When should race be taken into account when studying humans?
 * What definition of race is appropriate for biomedical research?
 * Do the biological differences between races justify the use of racial categories in research?
 * Can genetic assignment to population groups be used in lieu of self-identified race?
 * What are the ethical implications of using race in research?

The primary impetus for considering race in biomedical research is the possibility of improving the prevention and treatment of diseases. Many previous studies have observed that disease susceptibility and environmental responses vary by race. Thus, some researchers believe that race may be an informative category for biomedical research. Other researchers believe that racial categories have no valid biomedical applications, and may be socially harmful (Jackson, 2004).

Genetic differences among races
The biomedical relevance of genetic differences among races is a matter of debate. In general, genetic clusters exist that correspond roughly to the census definition of race and to self-identified ancestry. One large exception to this correspondence is that South, Central, and West Asians (e.g. Asian Indians) cluster with Europeans and are separate from East Asians. The association between race and genetics also breaks down for groups, such as Hispanics, that exhibit a pattern of geographical stratification of ancestry. Some researchers argue that the available evidence supports the notion that some of the genetic differences between races have biomedical significance, and thus should be studied.

An alternative view argues that the underlying genetic-cluster categories can be used in lieu of racial labels for biomedical purposes. Proponents of this view argue that by directly examining the genotype, the problem of using racial labels can be avoided. Moreover, they argue that genotyping is more reliable than using self-identified race as a proxy for ancestry. Some fear that the use of racial labels in biomedical research runs the risk of unintentionally exasperating health disparities, since doing so would mask risk factors such as exposure to racism and economic differences.

Proponents of using race in biomedical research argue that ignoring race will be detrimental to the health of minority groups. They argue that disease risk factors differ substantially between racial groups, that relying only on genotypical classes ignores non-genetic racial factors that impact health, and, furthermore, that minorities would be poorly represented in clinical trials if race were ignored.

These issues can be illustrated by looking at an example, sickle-cell disease. This disease has a clear relation to geographic origin since the associated gene also provides protection to a common tropical disease, Malaria. Thus, it is much more common in people of African descent than in whites. In an emergency room, this may help a doctor doing an initial diagnosis if a patient presents with symptoms compatible with this disease. However, this is still unreliable evidence. Testing the genotype by examining the blood of the patient gives the definitive evidence, not the race. Also, the disease does not follow absolute racial lines, it is most common in African American and Hispanics of Caribbean ancestry, but the trait has also been found in those with Middle Eastern, Indian, Latin American, Native American, and Mediterranean heritage, making it difficult to exclude patients who present with compatible symptoms simply based on race. Most diseases argued to have some correlation to race have much weaker correlation to geographic origin than sickle-cell disease, meaning that the value of knowing the race and not the exact genotype is even weaker.

Disease association studies
Michael Bamshad writes that inference about an individual’s ancestry trough self-identified race can make it easier to predict how likely an individual is to have a some disease-causing variants. HbSallele in sub-Saharan Africans and Southern Europeans or the C282Y-HFEand ∆508-CFTRalleles, which cause haemochromatosis and cystic fibrosis, respectively,in Northern Europeans are well known examples,but many others have been discovered. It is believed that many of these mutations first occurred in the population that is most affected.

The common disease-common variant (often abbreviated CD-CV) hypothesis predicts common disease causing alleles will be found in all populations. An often cited example is an allele of apolipoprotein E, APOE ε4, which is associated in a dose-dependent manner with susceptibility to Alzheimer's disease. This allele is found in Africans, Asians and Europeans. However, many disease causing alleles are found to have different (technically called epistatic) effects in different populations. For example, the increased risk of Alzheimer's disease that is associated with the APOE ε4 allele is 5-fold higher in individuals with Asian rather than African ancestry.

Polymorphisms in the regulatory region of the CCR5 gene affect the rate of progression to AIDS and death in HIV infected patients. While some CCR5 haplotypes are beneficial in multiple populations, other haplotypes have population-specific effects. For example, the HHE haplotype of CCR5 is associated with delayed disease progression in European-Americans, but accelerated disease progression in African-Americans. Similarly, alleles of the CARD15 (also called NOD2) gene are associated with Crohn's disease, an inflammatory bowel disorder, in European-Americans. However, none of these or any other alleles of CARD15 have been associated with Crohn's disease in African-Americans or Asians.

The effects of racial and ethnic identities on health
Although, considerable evidence indicates that the racial and ethnic health disparities observed in the United States arise mostly through the effects of discrimination, differences in treatment, poverty, lack of access to health care, health-related behaviors, racism, stress, and other socially mediated forces, differences in allele frequencies certainly contribute to group differences in the incidence of some monogenic diseases, and they may contribute to differences in the incidence of some common diseases (Risch et al. 2002; Burchard et al. 2003; Tate and Goldstein 2004). For the monogenic diseases, the frequency of causative alleles usually correlates best with ancestry, whether familial (for example, Ellis-van Creveld syndrome among the Pennsylvania Amish), ethnic (Tay-Sachs disease among Ashkenazi Jewish populations), or geographical (hemoglobinopathies among people with ancestors who lived in malarial regions). To the extent that ancestry corresponds with racial or ethnic groups or subgroups, the incidence of monogenic diseases can differ between groups categorized by race or ethnicity, and health-care professionals typically take these patterns into account in making diagnoses.

Even with common diseases involving numerous genetic variants and environmental factors, investigators point to evidence suggesting the involvement of differentially distributed alleles with small to moderate effects. Frequently cited examples include hypertension (Douglas et al. 1996), diabetes (Gower et al. 2003), obesity (Fernandez et al. 2003), and prostate cancer (Platz et al. 2000). However, in none of these cases has allelic variation in a susceptibility gene been shown to account for a significant fraction of the difference in disease prevalence among groups, and the role of genetic factors in generating these differences remains uncertain (Mountain and Risch 2004).

Human Genome Diversity Project
The Human Genome Diversity Project (HGDP) has attempted to map the DNA that varies between humans. In the future, HGDP could possibly reveal new data in disease surveillance, human development and anthropology. HGDP could unlock secrets behind and create new strategies for managing the vulnerability of ethnic groups to certain diseases. It could also show how human populations have adapted to these vulnerabilities. To date, HGDP research has resulted in a representative world distribution of 52 distinct genetic markers.

The project has raised ethical questions. Some worry that the results will be misued by racists. However, members of this project have been described as "liberals who argue that the project will help to reduce racism by showing that the concept of race is scientifically unsustainable" by Human Genetics Alert (HGA)