Race and health

Health disparities refer to gaps in the quality of health and health care across racial and ethnic groups.[11] The US Health Resources and Services Administration defines health disparities as "population-specific differences in the presence of disease, health outcomes, or access to health care".[12] Health is measured through variables such as life expectancy and incidence of diseases.[13]

For racial and ethnic minorities in the United States, health disparities take on many forms, including higher rates of chronic disease, premature death, and maternal mortality compared to the rates among whites. It is important to note that this pattern is not universal. Some minority groups—most notably, Hispanic immigrants—have better health outcomes than whites (Lara et al., 2005). This “immigrant paradox” appears to diminish with time spent in the United States, however (Lara et al., 2005). For other indicators, disparities have shrunk, not because of improvements among minorities but because of declines in the health of majority groups.

In the U.S., minority populations suffer disproportionately from chronic diseases. More than 133 million American (45% of the population)have one or more chronic diseases. Racial/ethnic minorities are 1.5 to 2.0 times more likely than whites to have most of the major chronic diseases. Hispanics and African Americans had the greatest prevalence of diabetes, while non-Hispanic blacks had higher odds of having heart disease with cancer or chronic lung disease than non-Hispanic whites.[14] 

Between 1960 and 2005 the percentage of children with a chronic disease in the United Stated quadrupled with minority having higher likelihood for these disease. The most common major chronic biases of youth in the United States are Asthma, diabetes mullets, obesity, hypertension, dental disease, attention- deficit/hyperactivity disorder, mental illness, cancers and others.

Although individuals from different environmental, continental, socioeconomic, and racial groups etc. have different levels of health, yet not all of these differences are always categorized or defined as health disparities. Some researchers separate definitions of health inequality from health disparity by preventability. Health inequalities are often categorized as being unavoidable i.e. due to age, while preventable unfair health outcomes are categorized as health inequities. These are seen as preventable because they are usually associated with income, education, race, ethnicity, gender, and more.[15]

Definitions of race are ambiguous due to the various paradigms used to discuss race. These definitions are a direct result of biological and social views. Definitions have changed throughout history to yield a modern understanding of race that is complex and fluid. Moreover, there is no one definition that stands, as there are many competing and interlocking ways to look at race.[16] Due to its ambiguity, terms such as race, genetic population, ethnicity, geographic population, and ancestry are used interchangeably in everyday discourse involving race. Some researchers critique this interchangeability noting that the conceptual differences between race and ethnicity are not widely agreed upon.[17]

Biological definitions of race encompass essentialist and anti-essentialist views. The scientific community does not universally accept a single definition of race. Essentialism is a mode of thought that uses scientific data to argue that racial groups are genetically distinct populations. Essentialists describe "races as groups of people who share certain innate, inherited biological traits, a.k.a. use of biological evidence to demonstrate racial differences".[18] As its counterpart, anti-essentialism uses biological evidence to demonstrate that "race groupings do not reflect patterns of human biological variation, countering essentialist claims to the contrary".[19] Despite Essentialism and anti-Essentialism views, modern scientific evidence suggests there are more genetic differences within individuals belonging to the same racial groups, than between individuals belonging to different racial groups.[20]

In the last 20 years there has been major criticisms on the once widely held view that race is biological. In response to these criticisms, researchers and social scientists have begun examining notions of race as constructed.[21] Racial groups are "constructed" from differing historical, political, and economic contexts, rather than corresponding to inherited, biological variations. Proponents of the constructionist view claim that biological definitions have been used to justify racism in the past and still have the potential to be used to encourage racist thinking in the future.[18] Since race is changing and often so loosely characterized on arbitrary phenotypes, and because it has no genetic basis, the only working definition we can assign it is a social construct. This is not to say race is imaginary or non-existent, it is very real and plays a role in our society; however to say that the concept of race has any scientific merit or has a scientific foundation can lead to many issues in scientific research, and it may also lead to inherent racial bias.[22]

Social views also better explain the ambiguity of racial definitions. An individual may self-identify as one race based on one set of determinants (for example, phenotype, culture, ancestry) while society may ascribe the person otherwise based on external forces and discrete racial standards. Dominant racial conceptions influence how individuals label both themselves and others within society.[23] Modern human populations are becoming more difficult to define within traditional racial boundaries due to racial admixture. Most scientific studies, applications, and government documents ask individuals to self-identify race from a limited assortment of common racial categories.[24] The conflict between self-identification and societal ascription further complicates biomedical research and public health policies. However complex its sociological roots, race has real biological ramifications; the intersection of race, science, and society permeates everyday life and influences human health via genetics, access to medical care, diagnosis, and treatment.

Diseases affect racial groups differently, especially when they are co-related with class disparities.[25] As socioeconomic factors influence the access to care,[26] the barriers to access healthcare systems can perpetuate different biological effects of diseases among racial groups that are not pre-determined by biology.

Some researchers advocate for the use of self-reported race as a way to trace socioeconomic disparities and its effects in health.[27] For instance, a study conducted by the National Health Service checks program in the United Kingdom, which aims to increase diagnosis across demographics, noted that "the reported lower screening in specific black and minority ethnic communities... may increase inequalities in health."[28] In this specific case, the lack of attention to certain demographics can be seen as a cause of increased instances of disease from this lack of proper, equal preventative care. One must consider these external factors when evaluating statistics on the prevalence of disease in populations, even though genetic components can play a role in predispositions to contracting some illnesses.

Individuals who share a similar genetic makeup can also share certain propensity or resistance to specific diseases. However, there are confronted positions in relation to the utility of using 'races' to talk about populations sharing a similar genetic makeup. Some geneticists argued that human variation is geographically structured and that genetic differences correlate with general conceptualizations of racial groups.[29] Others claimed that this correlation is too unstable and that the genetic differences are minimal and they are "distributed over the world in a discordant manner”.[30] Therefore, race is regarded by some as a useful tool for the assessment of genetic epidemiological risk,[31] while others consider it can lead to an increased underdiagnosis in 'low risk' populations.[32]

A positive correlation between minorities and a socioeconomic status of being low-income in industrialized and rural regions of the U.S. depict how low-income communities tend to include more individuals that have a lower educational background, most importantly in health. Income status, diet, and education all construct a higher burden for low-income minorities, to be conscious about their health. Research conducted by medical departments at universities in San Diego, Miami, Pennsylvania, and North Carolina suggested that minorities in regions where lower socioeconomic status is common, there was a direct relationship with unhealthy diets and greater distance of supermarkets.[51] Therefore, in areas where supermarkets are less accessible (food deserts) to impoverished areas, the more likely these groups are to purchase inexpensive fast food or just follow an unhealthy diet.[51] As a result, because food deserts are more prevalent in low income communities, minorities that reside in these areas are more prone to obesity, which can lead to diseases such as chronic kidney disease, hypertension, or diabetes.[51][52]

Furthermore, this can also occur when minorities living in rural areas undergoing urbanization, are introduced to fast food. A study done in Thailand focused on urbanized metropolitan areas, the students who participated in this study as were diagnosed as “non-obese” in their early life according to their BMI, however were increasingly at risk of developing Type 2 Diabetes, or obesity as adults, as opposed to young adults who lived in more rural areas during their early life.[53] Therefore, early exposure to urbanized regions can encourage unhealthy eating due to widespread presence of inexpensive fast food. Different racial populations that originate from more rural areas and then immigrate to the urbanized metropolitan areas can develop a fixation for a more westernized diet; this change in lifestyle typically occurs due to loss of traditional values when adapting to a new environment. For example, a 2009 study named CYKIDS was based on children from Cyprus, a country east of the Mediterranean Sea, who were evaluated by the KIDMED index to test their adherence to a mediterranean diet after changing from rural residence to an urban residence.[54] It was found that children in urban areas swapped their traditional dietary patterns for a diet favoring fast food.

The fact that every human has a unique genetic code is the key to techniques such as genetic fingerprinting. Versions of a trait, known as alleles, occur at different frequencies in different human populations; populations that are more geographically and ancestrally remote tend to differ more.

A phenotype is the "outward, physical manifestation" of an organism."[55] For humans, phenotypic differences are most readily seen via skin color, eye color, hair color, or height; however, any observable structure, function, or behavior can be considered part of a phenotype. A genotype is the "internally coded, inheritable information" carried by all living organisms. The human genome is encoded in DNA.[55]

For any trait of interest, observed differences among individuals "may be due to differences in the genes" coding for a trait or "the result of variation in environmental condition". This variability is due to gene-environment interactions that influence genetic expression patterns and trait heritability.[56]

For humans, there is "more genetic variation among individual people than between larger racial groups".[13] In general, an average of 80% of genetic variation exists within local populations, around 10% is between local populations within the same continent, and approximately 8% of variation occurs between large groups living on different continents.[57][58][59] Studies have found evidence of genetic differences between populations, but the distribution of genetic variants within and among human populations is impossible to describe succinctly because of the difficulty of defining a "population", the clinal nature of variation, and heterogeneity across the genome.[60] Thus, the racialization of science and medicine can lead to controversy when the term population and race are used interchangeably.

Evolutionary factors

See also: Heterozygote advantage

Malaria-endemic countries eastern hemisphere

Malaria-endemic countries western hemisphere

Genes may be under strong selection in response to local diseases. For example, people who are duffy negative tend to have higher resistance to malaria. Most Africans are duffy negative and most non-Africans are duffy positive.[61] A number of genetic diseases more prevalent in malaria-afflicted areas may provide some genetic resistance to malaria including sickle cell disease, thalassaemias, glucose-6-phosphate dehydrogenase, and possibly others.

Many theories about the origin of the cystic fibrosis have suggested that it provides a heterozygote advantage by giving resistance to diseases earlier common in Europe.

In earlier research, a common theory was the "common disease-common variant" model. It argues that for common illnesses, the genetic contribution comes from the additive or multiplicative effects of gene variants that each one is common in the population. Each such gene variant is argued to cause only a small risk of disease and no single variant is enough to cause the disease. An individual must have many of these common gene variants in order for the risk of disease to be substantial.[62]

More recent research indicates that the "common disease-rare variant" may be a better explanation for many common diseases. In this model, rare but higher-risk gene variants cause common diseases.[63] This model may be relevant for diseases that reduces fertility.[64] In contrast, for common genes associated with common disease to persist they must either have little effect during the reproductive period of life (like Alzheimer's disease) or provide some advantage in the original environment (like genes causing autoimmune diseases also providing resistance against infections). In either case varying frequencies of genes variants in different populations may be an explanation for health disparities.[62] Genetic variants associated with Alzheimer's disease, deep venous thrombosis, Crohn disease, and type 2 diabetes appear to adhere to "common disease-common variant" model.[65]

Public health researchers and policy makers are working to reduce health disparities. Health effects of racism are now a major area of research. In fact, these seem to be the primary research focus in biological and social sciences.[15] Interdisciplinary methods have been used to address how race affects health. according to published studies, many factors combine together to affect the health of individuals and communities.[21] Whether people are healthy or not, is determined by their circumstances and environment. Factors that need to be addressed when looking at health and race: income and social status, education, physical environment, social support networks, genetics, health services and gender.[15][70][71] These determinants are often cited in public health, anthropology, and other social science disciplines. The WHO categorizes these determinants into three broader topics: the social and economic environment, the physical environment, and the person's individual characteristics and behaviors. Due to the diversity of factors that often attribute to health disparities outcomes, interdisciplinary approaches are often implemented.[70]

Interdisciplinarity or interdisciplinary studies involves the combining of two or more academic disciplines into one activity (e.g., a research project) The term interdisciplinary is applied within education and training pedagogies to describe studies that use methods and insights of several established disciplines or traditional fields of study. Interdisciplinarity involves researchers, students, and teachers in the goals of connecting and integrating several academic schools of thought, professions, or technologies—along with their specific perspectives—in the pursuit of a common task.

There is a controversy regarding race as a method for classifying humans. Different sources argue it is purely social construct[75] or a biological reality reflecting average genetic group differences. New interest in human biological variation has resulted in a resurgence of the use of race in biomedicine.[76]

The main impetus for this development is the possibility of improving the prevention and treatment of certain diseases by predicting hard-to-ascertain factors, such as genetically conditioned health factors, based on more easily ascertained characteristics such as phenotype and racial self-identification. Since medical judgment often involves decision making under uncertain conditions,[77] many doctors consider it useful to take race into account when treating disease because diseases and treatment responses tend to cluster by geographic ancestry.[78] The discovery that more diseases than previously thought correlate with racial identification have further sparked the interest in using race as a proxy for bio-geographical ancestry and genetic buildup.

Race in medicine is used as an approximation for more specific genetic and environmental risk factors. Race is thus partly a surrogate for environmental factors such as differences in socioeconomic status that are known to affect health. It is also an imperfect surrogate for ancestral geographic regions and differences in gene frequencies between different ancestral populations and thus differences in genes that can affect health. This can give an approximation of probability for disease or for preferred treatment, although the approximation is less than perfect.[13]

Taking the example of sickle-cell disease, in an emergency room, knowing the geographic origin of a patient may help a doctor doing an initial diagnosis if a patient presents with symptoms compatible with this disease. This is unreliable evidence with the disease being present in many different groups as noted above with the trait also present in some Mediterranean European populations. Definitive diagnosis comes from examining the blood of the patient. In the US, screening for sickle cell anemia is done on all newborns regardless of race.[77]

The continued use of racial categories has been criticized. Apart from the general controversy regarding race, some argue that the continued use of racial categories in health care and as risk factors could result in increased stereotyping and discrimination in society and health services.[13][79][80] Some of those who are critical of race as a biological concept see race as socially meaningful group that is important to study epidemiologically in order to reduce disparities.[81] For example, some racial groups are less likely than others to receive adequate treatment for osteoporosis, even after risk factors have been assessed. Since the 19th century, blacks have been thought to have thicker bones than whites have and to lose bone mass more slowly with age.[82] In a recent study, African Americans were shown to be substantially less likely to receive prescription osteoporosis medications than Caucasians. Men were also significantly less likely to be treated compared with women. This discrepancy may be due to physicians' knowledge that, on average, African Americans are at lower risk for osteoporosis than Caucasians. It may be possible that these physicians generalize this data to high-risk African-Americans, leading them to fail to appropriately assess and manage these individuals' osteoporosis.[82] On the other hand, some of those who are critical of race as a biological concept see race as socially meaningful group that is important to study epidemiologically in order to reduce disparities.

David Williams (1994) argued, after an examination of articles in the journal Health Services Research during the 1966–90 period, that how race was determined and defined was seldom described. At a minimum, researchers should describe if race was assessed by self-report, proxy report, extraction from records, or direct observation. Race was also often used questionable, such as an indicator of socioeconomic status.[83] Racial genetic explanations may be overemphasized, ignoring the interaction with and the role of the environment.[84]

One area in which population categories can be important considerations in genetics research is in controlling for confounding between population genetic substructure, environmental exposures, and health outcomes. Association studies can produce spurious results if cases and controls have differing allele frequencies for genes that are not related to the disease being studied,[88][89] although the magnitude of its problem in genetic association studies is subject to debate.[90][91] Various techniques detect and account for population substructure,[92][93] but these methods can be difficult to apply in practice.[94]

Population genetic substructure also can aid genetic association studies. For example, populations that represent recent mixtures of separated ancestral groups can exhibit longer-range linkage disequilibrium between susceptibility alleles and genetic markers than is the case for other populations.[95][96][97][98] Genetic studies can use this disequilibrium to search for disease alleles with fewer markers than would be needed otherwise. Association studies also can take advantage of the contrasting experiences of racial or ethnic groups, including migrant groups, to search for interactions between particular alleles and environmental factors that might influence health.[99][100]

The Human Genome Diversity Project has collected genetic samples from 52 indigenous populations.

In a report by the Institute of Medicine called Unequal Treatment, three major source categories are put forth as potential explanations for disparities in health care: patient-level variables, healthcare system-level factors, and care process-level variables.[101]

• Dark skin § Health implications
• Light skin § Health implications
• HapMap[102]
• Average height around the world § Notes
• List of countries by life expectancy
• Ethnic bioweapon
• Environmental racism in Europe
• Social determinants of health
• Social determinants of health in poverty § Ethnicity
• Ethnopsychopharmacology
• Category:Human genome projects

United States:

• Race and health in the United States
• Center for Minority Health, US.
• Environmental racism

General:

• Health disparities
• Pharmacogenomics
• Medical genetics
• Personal genomics

• Cultural Diversity in Healthcare Speaker Series University of Wisconsin School of Medicine and Public Health
• Cultural Diversity in Healthcare Research Symposium University of Wisconsin School of Medicine and Public Health
• News-Medical.net
• Unnatural causes, videos on how racial inequalities influence health