One of the great, unsolved mysteries in medicine is explaining why health and longevity tend to increase with socioeconomic status – even among those who are materially secure. There is no threshold at which the link between increasing SES and better average health comes to an end.
Access to health care and differences in health behavior, such as smoking and eating habits, only account for part of the link between socioeconomic status and health.
Allostatic load theory attempts to explain how psychological and social experiences “get under the skin” and give rise to disease. The basic idea is that repeated stressful experiences can build up over time, gradually wearing down the body’s regulatory systems, opening the door to the onset and progression of many different diseases. Bruce McEwen and Teresa Seeman explain,
“For each system of the body, there are both short-term adaptive actions (allostasis) that are protective and long-term effects that can be damaging (allostatic load). For the cardiovascular system, a prominent example of allostasis is the role of catecholamines in promoting adaptation by adjusting heart rate and blood pressure to sleeping, waking, physical exertion. Yet, repeated surges of blood pressure in the face of job stress or the failure to shut off blood pressure surges efficiently accelerates atherosclerosis and synergizes with metabolic hormones to produce Type II diabetes, and this constitutes a type of allostatic load.”
Measures of allostatic load are supposed to reflect how well or poorly the cardiovascular, metabolic, nervous, hormonal and immune systems are functioning. Higher scores indicate greater vulnerability to illness. Researchers have proposed different ways to score allostatic load. They combine the results of various tests: blood pressure, body mass index (or waist-hip radio), kidney function, blood sugar, cholesterol, C-reactive protein, and cortisol and other hormones that regulate the response to stress.
By combining multiple test results in one index, researchers are trying to capture the accumulated effect on all physiological systems, including feedback loops between those systems.
It’s possible that this approach might give researchers and public health officials a more immediate way to test the results of policies or programs designed to reduce health disparities. Because it may take years to see an impact on disease outcomes, some effective programs may appear to be ineffective if evaluated over too short a time horizon.
People with higher allostatic load scores who have been tracked for years in observational studies are more likely to develop heart disease, experience cognitive and functional decline, and die prematurely.
Numerous studies have found that allostatic load builds up faster in people lower on the socioeoncomic ladder. Higher allostatic loads emerge as early as the first five years of life and persist throughout childhood, adulthood and older age. People living in disadvantaged neighborhoods have significantly more biological “wear and tear” as measured by allostatic load, above and beyond the effect of individuals’ income, education and race or ethnicity.
African Americans tend to have higher allostatic loads than white people, and higher poverty rates among blacks do not account for the difference. In fact, in one national analysis, high allostatic load scores were more prevalent among nonpoor blacks than among poor whites. The average score for blacks was roughly equal to the score for whites who were 10 years older.
Current evidence does not provide definitive support for the proposed links between psychological and social stresses and dysregulation of biological systems. The field continues to debate which physiological measurements should be included in the allostatic load index. Some researchers question whether the indices used to score allostatic load are actually measuring the processes by which repeated stressful experiences shape health over the life course. In a recent study examining the elevated rate of poor birth outcomes among African American women, for example, allostatic load scores surprisingly did not correlate with preterm birth or low birth weight.
Research linking socioeconomic status and health is almost all observational, which means it shows correlation, not causation. So the research does not firmly establish that low income, lack of education or low social status cause poor health. Most often, the influences are likely to be reciprocal: social status affects health and health affects social status. Chronic illness, for instance, can hinder success in education, employment, and earnings.
Some authors assert that socioeconomic status is a proxy rather than a true cause of health inequalities, and emphasize behavioral risk factors that are under the control of individuals.
The debate is not merely academic. It’s still not clear, for instance to what extent investing in education or income transfers would improve population health. Attempts to use tax credits, income support, or school funding to improve health aren’t likely to work if income and education aren’t primary causes of the social gradient in health. If they are primary causes, solutions focused on individual behavior don’t stand much chance of success.
Medical experts have long urged the government and health systems to address the health consequences of climate change and their disproportionate effects on vulnerable communities. The new DHHS Office of Climate Change and Health Equity (OCCHE) opened on August 30, 2021 is the first federal program aimed specifically at understanding how planet-warming greenhouse gas emissions from burning fossil fuels also affect human health. Climate change exacerbates existing health and social inequities by worsening environmental conditions associated with chronic illness and injury. It also increases food insecurity, worsens air pollution, reduces our access to clean water, displaces people from their homes and causes widespread social and economic disruption.
Culturally appropriate care
A health care approach that acknowledges the influence of cultural values and beliefs (for the patient and provider) in health care delivery and provides care to address cultural needs. It is useful when describing health interventions, educational materials, etc.
Disability and health disparities
Disability is unique among factors related to health disparities because it is both directly a health issue and an issue that affects health. In addition, people can have disabilities that are not necessarily medical in nature but that still affect other aspects of health. Although a single term, the word “disability” is likely broader than most factors that relate to health inequities.
Almost 1 in 4 (18.7 percent) of the U.S. population has a disability, but how that manifests varies from person to person, sometimes from day to day, and with a broad diversity even for people with the same diagnosis. What everyone with a disability has in common is that the true determinant of their condition is the environment and what it makes accessible — and not accessible — to them. Environment can be everything from locational (accessible sidewalks, public transit, food islands) to educational obstacles (physical, bureaucratic and pedagogical) and social constructs that willfully or accidentally include or exclude people with specific disabilities, including from meaningful employment.
On the health care access front, people with disabilities experience a host of worse outcomes, from being less likely to access preventive care to having higher mortality rates.
Disability also interacts with other social determinants of health, including ethnicity, income and education level, and gender.
Despite its central role in disparity and its permanent partnership with human existence, disability as a factor in health disparities has only recently started to draw significant attention. That means that journalists who cover health are seeing the beginning stages of emerging insights into how disability affects and interacts with other social determinants of health.
The U.S. government portal, Healthy People 2020, focuses on health disparities, and its page on disability is here.
The American Association on Health and Disability offers a brief white paper on disability-related disparity stats and interacting factors, along with a critique of the gaps in Healthy People 2020.
This 2018 analysis from the journal Social Forces takes a look at factors that interact with disability to create health disparities. It uses a sociological perspective and provides a good overview of two ways of viewing or framing disability: the social model and the medical model.
This commentary from Tufts gets to one reason disability is “emerging” in health disparity studies despite being ever present: the focus used to be on prevention.
Education and health
Education may be the aspect of socioeconomic status offering society the most powerful way to improve population health. And numerous studies have revealed that Americans with fewer years of education are falling farther behind in almost every measure of health status. Education acts on several levels:
Increases knowledge, problem-solving, and coping skills, thus helping people make better-informed health choices. (People with more education are quicker to adopt changes in health-related behaviors in response to new evidence.)
Improves chances of securing a job with healthy working conditions, better employment-based benefits and higher wages. The job security and higher income that tend to come with more education provide a buffer from chronic stress - a corrosive force that undermines health among lesser educated, lower income people.
Gives people a greater sense of personal control. Positive beliefs about personal control have a profound impact on how people approach life, make decisions about risky behavior, and cope with illness.
Since 1980, life expectancy has changed very little among the less-educated and virtually all gains in life expectancy occurred among highly educated groups. From 1990 to 2008, the disparity in life expectancy between the most and least educated increased from 7.7 years to 10.3 years for women, and from 13.4 years to 14.2 years for men, the journal Health Affairsreported in 2012. Adults with fewer than 12 years of education now have life expectancies not much better than those of the overall U.S. population in the 1950s.
The links between education and health are complex and intertwined. For instance, while education creates opportunities for better health, poor health can also undermine educational attainment. And living conditions – especially at birth and in early childhood – profoundly shape both health and education. That means that improving the deteriorating health of Americans with fewer years of education will most likely require policies that go beyond schooling to include early child care, housing, transportation, food security, unemployment, and economic development.
Income, education, neighborhood environment and other social forces shape and limit the food choices people make.
For instance, studies consistently have found a socioeconomic gradient in food choices: at lower levels of socioeconomic status, the consumption of whole grains, lean meats, fish, low-fat dairy products, and fresh vegetables and fruit decreases while the consumption of fatty meats, refined grains, and added fats increases.
Cultural ways influence food preferences, such as the heavier meat consumption researchers have noted in low-income households. Investigators who interviewed nearly 100 low-income mothers in Minnesota found that ethnic traditions were influential, along with taste, meat’s versatility in meal preparation, and the importance of meat as a status symbol. Meat preferences also reveal how differing education plays a role. In recent years, Americans higher up on the ladder of education and income status have cut back on red meat consumption since it’s been tied to higher rates of cancer and other health risks.
People living in lower income places also tend to be surrounded by less healthy offerings: fast food restaurants with “dollar” menus and corner stores selling snack foods rather than boutique green grocers and farmers’ markets selling fresh produce. Lower income neighborhoods also are subject to a heavier barrage of advertising for unhealthy food and drink than wealthier neighborhoods.
Among people in lower income populations, price appears to be a significant driver of food choices. A recent meta-analysis by researchers at Brown University and the Harvard School of Public Health calculated that healthy eating costs about $1.50 more per day per adult than eating a low-quality diet ($550 more annually per person). That extra cost represents a 25 percent increase for a household that spends $6 per person on food each day, which is more than many low-income families spend. An earlier study found that the cost of substituting healthier foods can cost 35 to 40 percent of an American low-income family's food budget.
Energy-dense foods (made of processed grains, sugar, and fat) are typically the most affordable choices. Such fare also has a longer shelf-life, which is extra meaningful for people short on money and needing to minimize waste. Processed foods also cost less in terms of the time it takes to plan and prepare meals for those struggling to work long hours outside the home while handling childcare and housekeeping.
Some studies have shown that healthy food choices don’t necessarily have to increase household food spending. In a recent Canadian study, for example, researchers tracked 73 women who adopted a Mediterranean diet and found that it didn’t cost them more. But that study included mostly college educated women, all from households earning well above the poverty level. Studies including disadvantaged households (e.g. here and here) suggest that such families can often barely afford food, purchase most of their groceries at the lowest available prices, and would probably have to pay more to adopt healthier choices.
Health and longevity tend to decrease with poverty and social isolation. This link has persisted since at least the early 1800s, which is hard to explain given that the U.S. and other wealthy nations have practically eliminated all of the infectious diseases that seemed to account for the unequal burden of death in poor households and neighborhoods in earlier times. Inequalities in mortality have continued at more or less the same level. All that has changed are the major causes of death, which are now cancers and chronic disease of the heart and vascular system.
Social scientists Jo Phelan and Bruce Link were among the first to make the case that inequalities in health are unlikely to change unless policy makers address inequalities in income, education, and social status. Link and Phelan developed an influential theory that describes how social forces are the fundamental causes of health disparities.
A fundamental cause, according to these authors, involves access to resources people can use to avoid or minimize a broad range of health risks:
For example, a person with many resources can afford to live in a high-SES neighborhood where neighbors are also of high status and where, collectively, enormous clout is exerted to ensure that crime, noise, violence, pollution, traffic, and vermin are minimized, and that the best health-care facilities, parks, playgrounds, and food stores are located nearby. Once a person has used [socioeconomic status]-related resources to locate in an advantaged neighborhood, a host of health-enhancing circumstances comes along as a package deal. Similarly, a person who uses educational credentials to procure a high-status occupation inherits a package deal that is more likely to include excellent health benefits and less likely to involve dangerous conditions and toxic exposures. In these circumstances, the person benefits in numerous ways that do not depend on his or her own initiative or ability to personally construct a healthy situation; it is an “add on” benefit operative at the contextual level.
Resources also shape individual health behavior, that is, whether people “know about, have access to, can afford, and receive social support for their efforts to engage in health-enhancing or health-protective behaviors,” in the words of Phelan, Link and Parisa Tehranifar. When cancer screening tests were first invented, for example, people with more resources were the first to gain access. Even now, screening rates for cervical and breast cancer remain higher among those with more education and income.
Resources such as knowledge, money, power, prestige, and beneficial social connections can be used no matter the prevailing health risks or available protective steps at any point in history. And this, according to the theory, is how socioeconomic status continues to shape health status even as the major threats and ways to avoid them change dramatically over time.
The theory predicts that mortality should be more equal for diseases that medicine still can’t prevent or effectively treat, and numerous studies support this hypothesis. Cancer survival, for instance, is worse among disadvantaged minority groups and the poor, but the survival gaps shrink for the types of cancer that aren’t amenable to existing treatments, according to a study based on national cancer statistics.
Another study found that the survival advantage of more-educated individuals increases in the case of diseases with more rapid progress in treatment technology. The authors used two measures of treatment progress: the number of approved drugs to treat a disease, and the rate of change in mortality from that disease.
Sociologists Karen Lutfey and Jeremy Freese identified a “massive multiplicity of mechanisms” by which socioeconomic status acts as a fundamental cause of inequality in health outcomes. Their influential 2005 study used ethnographic analysis to compare the experience of diabetes treatment in two contrasting clinics, one with mostly white, middle- and upper-class patients, the other serving mostly minority, working class and under-insured patients.
Thinking about fundamental causes leads to different policies for addressing health inequalities than the prevailing approaches based on individual risk factors. Medical providers and public health campaigns typically identify modifiable risk factors (e.g. smoking, high blood pressure, lack of exercise, poor diet) and target individuals with interventions that attempt to change those individual risk factors. Fundamental causes theory predicts that interventions that aim solely to change individual risk factors will tend to worsen social inequalities in health. And there is some evidence that this really happens.
Phelan and coauthors assert that:
• Efforts to change individual risk profiles should first identify factors that put people “at risk of risks,” for example, overcrowded and dangerous neighborhoods with failing public schools and limited access to affordable, wholesome food. The idea is to avoid ineffective public health campaigns aimed at changing behaviors that are powerfully influenced by conditions left untouched by the intervention.
• Policies that aren’t normally considered health interventions may be the most effective way to reduce health disparities if they reduce resource inequalities. This could include, for example, minimum wage and parenting leave laws, head-start programs, housing for homeless and low-income people, college-admission policies, regulation of lending practices, and so on.
In the 1960s, anthropologist Oscar Lewis asserted that residents of poor urban ghettos absorb a “culture of poverty” in their early socialization and carry it with them into adulthood. In the words of James Rosenbaum and co-authors, "The fatalism underlying the culture of poverty affects everything they do; in effect, culture is internal. Similarly, in the traditional psychological view, efficacy is an aspect of an individual’s personality, an early formed, relatively stable characteristic that is unlikely to change."
But researchers in more recent years have found evidence to the contrary. They have proposed a “geography of opportunity” model of health disparities based on findings that neighborhood environments profoundly shape people’s health, schooling, employment opportunities, and quality of life. While the culture of poverty model assumes that low-income individuals who acquire a low sense of efficacy will tend to be stuck with it, the geography of opportunity model suggests that moving from disadvantaged neighborhoods will enable people to regain a sense of efficacy.
Better neighborhoods create opportunities in many different ways:
Provide access to more jobs, greater variety of jobs, and closer jobs.
Avoid the stigma of a housing project address, which makes it harder to get a job, and harder to get credit, which increases the costs of debt.
Ability to get jobs and credit gives people opportunity to see themselves as capable of being financially independent.
Integration improves people’s efficacy, as they realize that they are able to interact with people from other backgrounds as peers and friends.
Provides information and access to ways of attaining goals, for example, through better public schools and enrichment programs.
Gaining confidence from being around peers confident in their ability to succeed.
Chicago’s Gautreaux Program, ordered by a Supreme Court decision in 1976, permitted thousands of low-income blacks to live in middle-income white suburbs. Between 1976 and 1998, over 7,000 families participated, and more than half moved to suburbs.
Studies tracking participants found that moving to a new environment could drastically change a person’s outlook. In an example cited by Rosenbaum and colleagues, “Ms. P” equated the housing projects to prison and found freedom in the suburbs:
I think it was the richness in the atmosphere that the children realized … they no longer had to be in the projects; they no longer had to dodge bricks and things coming in the building where they lived. Here they could just sit out and enjoy themselves, and they did… Because it was like living in a prison, you know. And when you can’t go out whenever you like and play or whatever—I had to go out with my kids—it’s hard. But up here, it’s a lot different; it’s quieter, much quieter. I’m able to sleep at night.
Moving to the suburbs removed some people from bad influences that had limited their efficacy. “Ms. Q” reported that prior to her move, she was "hanging with the wrong crowd."
The young adults around her were partying into the early hours, sleeping late, watching television through the day, and some were involved with drugs. She found it difficult to avoid these activities if she was to interact with her neighbors. Having a job did not fit into this life style. After moving to the suburbs, she reports, “Now I’m trying to work and better my life … I have a better house, but I can’t live off of this [Program] forever, so now I’m trying to strive and get going back to school and trying to work and just better myself." In her old neighborhood, Ms. Q felt constrained by poor role models, peer pressure and a lack of opportunity. Living in the suburbs gave her a new outlook; she began to realize that she could actively control her life: “I felt better about where I lived, and that made me want to try to do something with my life other than just sit back and be nervous and worried all the time.”
The federal Moving to Opportunity Program provided another test of the geography of opportunity, but produced some strikingly conflicting results. Moving out of impoverished neighborhoods resulted in some health gains for girls, for instance, but made things substantially worse for boys.
The program enrolled about 4,600 families in public or project-based assisted housing in high-poverty areas of Baltimore, Boston, Chicago, Los Angeles, and New York from 1994 to 1998. Researchers randomly assigned families to three groups: Some received vouchers to move to low-poverty neighborhoods, some received traditional vouchers enabling them to move but with no geographic restriction, and some received no change in the level of assistance. Researchers compared health outcomes 10 to 15 years later.
Girls in the traditional voucher group had decreased rates of major depression and conduct disorder, and girls in the low-poverty voucher group had no statistical differences, compared with those in the control group. Boys in the low-poverty voucher group had substantially increased rates of major depression, posttraumatic stress disorder, and conduct disorder compared with those in the control group. And boys in the traditional voucher group had an increased rate of posttraumatic stress disorder, the authors reported in JAMA.
The program also found no consistent impacts on adult economic self-sufficiency or children’s educational achievement.
Critics of the Moving to Opportunity study note that those who left public housing often moved into segregated neighborhoods lacking job opportunities and good schools. Social conditions weren’t significantly better than the ones they left.
People whose socioeconomic status is low are more likely to act in ways that harm their health compared with those higher on the ladder of income and social stature. On average, they smoke more, exercise less, have poorer diets, and more often ignore health advice and fail to comply with treatment. As a group, they are even less likely to use seatbelts.
Researchers have proposed many theories to explain why this is so, and these involve more than the inability to pay for goods and services that promote health. (Cigarettes are expensive, after all.) Walking and many other forms of exercise don’t require money, and neither does clicking a seatbelt.
Investing less in health behavior may be a positive adaptation to socioeconomic deprivation, according to a theory inspired by evolutionary biology. In other words, it’s like deciding to spend little on car maintenance when you live in a neighborhood of rampant car theft. Living under threat of high mortality from outside causes may set a limit on how much energy it is worth to put into lowering mortality from internal causes.
Another explanation that’s recently drawn a lot of media attention is the idea that poverty overloads the capacity of the brain to make sound decisions, an idea elaborated in the book Scarcity: Why Having Too Little Means So Much.
It’s important to note that the social patterning of unhealthy behaviors is not the same in every country. In France, for example, people on the upper end of the social ladder are almost as likely to smoke, eat poorly and neglect physical activity as people farther down the ladder, a recent study found.
So far, there is no grand unified theory that accounts for all social, psychological and political forces that press on people on the lower rungs of the socioeconomic ladder. In an informative review, Fred C. Pampel, Patrick M. Krueger, and Justin T. Denney break down the evidence for and against nine major pathways by which socioeconomic status shapes health behavior:
1. Self-medicating response to stress: Smoking, overeating, and inactivity provide pleasure and relaxation that help regulate mood among the disadvantaged. This “self-medicating” function makes these behaviors tough to give up.
2. Fatalism and discounting the future: Lower lifetime earnings and wealth give people less reason to invest in future longevity and more reason to focus on the present in making decisions about health behaviors. People in disadvantaged circumstances may believe they gain little in terms of longevity from healthy behavior and feel fatalistic about their ability to act in ways that extend their lives.
3. Latent traits: Some traits related to intelligence and self-control are set early in life and to some extent determine school and employment success as well as adult health behaviors. To what extent this happens remains a matter of huge debate.
4. Class distinctions: As with fashion, people adopt lifestyle habits at least partly to reinforce their social position. Class distinction is part of what motivates more educated and wealthy people to swear off cigarettes, adopt a Mediterranean diet and spend hours per week doing yoga and Pilates. Likewise, class distinction may also motivate people with less education and income to set themselves apart with behaviors such as smoking that have come to symbolize independence, toughness, and freedom from convention.
5. Lack of knowledge and access to information: People with limited education are less knowledgeable of the harms of unhealthy behavior. If they live in a disadvantaged neighborhood, they are likely to be exposed to more advertising that promotes tobacco, liquor and unhealthy food.
6. Education and efficacy: Schooling increases problem-solving skills, ability to process information, self-control and efficacy. These are useful tools for overcoming the inertia of inactivity, the discomfort of exercise, and the desire for tobacco, unhealthy foods and excess calories.
7. Ability to pay: Adopting healthy behaviors does not always require money, but having money makes it easier to take steps such as buying nicotine patches to quit smoking, joining a health club, or eating fresh fruits, vegetables, and lean meats. In this way, disposable income can help overcome low education, efficacy, and agency.
8. Neighborhood opportunity: Communities shape opportunities to adopt and maintain healthy behaviors. Low-income neighborhoods have more than their share of fast-food restaurants, liquor stores, and places to buy cigarettes and have less than their share of large grocery stores with a wide selection of healthy fresh foods.
9. Social Support, cohesion, and peer influence: Networks of family members, relatives, friends, and neighbors can support healthy behavior, discourage unhealthy behavior, and share information on ways to change. Or they can do the reverse. Wealthier and more educated people tend to associate with other high-SES persons in networks that promote health. People with less education and living in poorer neighborhoods have networks that can promote unhealthy behavior.
Researchers have done little to systematically compare the relative impact of these interacting forces, Pampel and co-authors note. They say it’s crucial to understand the difference between having the motivation versus having the means for healthy behavior. The stress response, fatalism, class distinctions, and knowledge of risk emphasize how socioeconomic status alters the motivation for healthy behavior. Education, income, and neighborhood opportunity focus more on how socioeconomic status can limit the means for healthy behavior.
“The distinction between motives and means tends to blur at the edges, as strong motives increase efforts to find effective means, and possessing scant means tends to sap motivation to change,” they say. “However, motives and means are analytically distinct, and distinguishing among them may aid in the study of disparities in health behaviors.”
The research suggests that it takes more than self-motivation to overcome poverty and the social determinants of unhealthy behavior.
Prosperity and advances in public health and medicine have pushed average life expectancy steadily upward–but not for everyone in the United States.
In many corners of the country, women and men are dying younger than they did 20 years ago. From 1983 to 1999, life expectancy among U.S. women fell by more than a year in 180 counties, and among men in 11 counties. Babies born in some U.S. neighborhoods have an average life expectancy 25 years shorter than their peers in more affluent enclaves just a few miles away.
These are examples of health disparities: health differences that are avoidable, unnecessary and unjust. Health inequalities, a more or less synonymous term, is seeing more use among researchers and public health officials because it more explicitly raises the issue of justice.
Not all health differences are health disparities. For example, worse health among the aged compared with the young, and higher rates of arm injuries among professional tennis players than in the general population don’t qualify, Paula Braveman, M.D., M.P.H., explains in a recent article. A serious disease outbreak in an affluent community not seen in less affluent communities would deserve attention but for reasons other than relevance to health disparities, she writes. “None of these examples reflects what is at the heart of the concept of health disparities: concerns about social justice—that is, justice with respect to the treatment of more advantaged vs. less advantaged socioeconomic groups when it comes to health and health care.”
Health disparities present a difficult challenge for policy makers. Social scientists have amassed convincing evidence that the root of the problem is economic and social disadvantage, which make people more vulnerable to illness, disability, suffering, and premature death. That means that to ameliorate health disparities will require more than expanding access to health insurance and medical care. It will require new policies that more effectively reduce poverty, increase economic opportunity, and prevent discrimination in education, housing and jobs.
The definition of health equity has been evolving over at least three decades. To provide a clear definition of the concept, public health researchers, physicians, social scientists and other experts in the U.S. and other countries have drawn from laws and principles in the field of human rights, including the constitution of the World Health Organization and the U.N. Declaration of Human Rights. In studies and editorials, argue that at the heart of the definition of health equity are matters of fairness, justice, and morality.
A lay definition of health equity may be this: a state wherein everyone is allowed to live their healthiest possible lives, regardless of their educational attainment, living environment, income level, age, gender, ethnicity, race and other social conditions and demographic characteristics. British public health researcher Margaret Whitehead, Ph.D., a professor at the University of Liverpool, has been at the forefront of studying health equity in Europe and is widely credited with the present definition of the term. Whitehead, however, uses the expression health inequalities, which is more widely used in Europe and implicitly suggests that socioeconomic inequities are at the root of the concept. In a 2006 WHO report Whitehead co-authored, she and her colleague offer the following definition of what has been described as a principle:
“…equity in health implies that ideally everyone could attain their full health potential and that no one should be disadvantaged from achieving this potential because of their social position or other socially determined circumstance.”
In the U.S., Paula Braverman, M.D, Director of the Center on Social Disparities in Health at the University of California, San Francisco (UCSF), has been at the forefront of health equity research in that country. Braverman has said that health equity is about providing everyone with the economic, environmental, and educational opportunities, among others, to achieve their best possible health, and “giving special attention to the needs of those at greatest risk of poor health, based on social conditions.”
While public health researchers, policymakers, physicians, and others have created more awareness about health equity in recent years, the concept can be traced to at least the middle of the 19th century. As the Industrial Revolution created rapid technological advances, urbanization and economic growth, physicians and researchers were studying the relationship between harsh environments, cramped living conditions, access to sanitation, and disease trends.
Some public health researchers have said the roots of health equity are in social medicine. Jules Guérin, Rudolf Virchow, Salomon Neumann and Rudolf Leubuscher were among French and German medical doctors and others who argued quality of health was also tied to social factors. At the turn of the 20th century, U.S. Black intellectuals such as W.E.B Dubois and Booker T. Washington were sounding alarm bells about troubling health trends in Black Americans that they argued were a consequence of centuries of slavery.
Health impact assessment
Elected leaders and policy makers have opportunities to make choices that – if they take health into account – could help ameliorate public health problems such as the obesity epidemic and the large and growing disparities in the burden of chronic disease.
Health impact assessment, or HIA, is a way to scrutinize the effects a government program or project may have on the health of a population. The systematic process is supposed to help policy makers avoid unintended harmful effects and take advantage of opportunities to promote health.
According to the The Health Impact Project, an initiative of the Robert Wood Johnson Foundation and The Pew Charitable Trusts, "HIA gives federal, tribal, state and local legislators, public agencies and other decision makers the information they need to advance smarter policies today to help build safe, thriving communities tomorrow."
The number of assessments has mushroomed from a few dozen in 2007 to more than 240 completed or in progress in 35 states, Washington, D.C., Puerto Rico, and at the federal level as of 2013, according to a recent Institute of Medicine report.
After a health impact assessment in Alaska, the Bureau of Land Management in 2007 withdrew part of an oil and gas development lease that threatened the health of native populations, and the approved lease required new pollution monitoring and controls.
A health impact assessment helped resolve concerns about a proposed biomass energy project in Placer County, Calif., in 2012. The assessment found that the project would likely benefit community health in the Lake Tahoe Region through the removal of forest slash and reduction of wildfire fuels, the diversion of open pile burns to more emission efficient combustion and the diversification of energy sources.
Boston’s regional transit agency in 2013 held off imposing steep fare increases and service cuts after a health impact assessment concluded that it would lead to significant health and financial costs because of increased automobile use.
How they’re done:
Assessments generally follow a six-step process.
1. Screening: Decide whether a HIA is warranted and would be useful in the decision-making process.
2. Scoping: Choose which health impacts to evaluate, the methods for analysis, and a workplan for completing the assessment.
3. Assessment: Gather data and predict health impacts using qualitative and quantitative research methods.
4. Recommendations: Prioritize evidence-based proposals to mitigate negative health impacts and maximize positive health impacts.
5. Reporting: Communicate findings.
6. Monitoring: Evaluate the effects of the impact assessment on the decision-making process.
The Robert Wood Johnson Foundation recently analyzed 23 health impact assessments completed between 2005 and 2013. Most weren’t given enough time or money, the authors concluded. People doing the assessments struggled to find relevant, neighborhood-level data, and they found it tough to make headway in politically charged situations. In some cases, agencies moved ahead on project decisions without waiting for completion of the health impact assessment.
As communication continues to rapidly change, experts are reexamining the fundamentals of health literacy and reevaluating the steps needed to improve it.
As with general literacy, a complex web of social factors can affect an individual’s health literacy skills. At the same time, widely available online health information and health technology are also changing how people access and comprehend their own health and how providers are grappling with the issue.
“During the coming decade, the speed, scope, and scale of adoption of health IT will only increase. Social media and emerging technologies promise to blur the line between expert and peer health information. Monitoring and assessing the impact of these new media, including mobile health, on public health will be challenging,” experts with the U.S. Department of Health and Human Service said wrote in a report for HealthyPeople2020. The major initiative aimed at improving Americans’ health is in part focused on the role of health communication and technology to improve health outcomes.
According to the Institute of Medicine, about half of all U.S. adults lack the ability to understand health information and act on it. Yet that ability is more likely than other factors such as education, income or race to predict a person’s health. Most at risk are those who are chronically ill as well as seniors.
In fact, researchers now regard health literacy as a concept that is still evolving, rather than a static one tied simply to basic reading and comprehension. The IOM created a panel to weigh ongoing issues with literacy regarding health, including culture and technology.
People who are homeless face many health threats and are among the heaviest users of hospital services. Safe and affordable housing, some experts assert, is a necessary first step to care effectively for people with chronic mental health and substance abuse problems who live on the streets. And there is some evidence that this approach may, in some circumstances, even save taxpayers money (but probably not as much as is often claimed).
In an influential 2009 study in Seattle, researchers analyzed medical and law enforcement costs for 91 people given supportive housing and found that costs dropped to about half the level seen among 35 comparable homeless people on a waiting list. But note that this savings estimate doesn’t include the capital costs of building and refurbishing apartments. Raising capital is likely to be a tall hurdle for many communities and this issue often gets ignored in news reports about the promise of supportive housing.
News coverage sometimes overstates the potential cost savings. In a study of supportive housing in Chicago, the savings were statistically insignificant. In a five-city study, clients in supportive housing wound up costing more than a comparison group of people not given housing.
Some advocates assert that saving money is an unfair requirement for a medical intervention that effectively relieves suffering. The cost-effectiveness of medical interventions is customarily measured in terms of quality-adjusted life-years gained, not dollars saved.
Housing First, a model developed by New York-based Pathways to Housing and others, has occasionally provoked controversy because of its “harm reduction” approach. Tenants are not required to take part in rehab or abstain from drugs or alcohol to remain eligible.
Some outstanding questions include:
Can cities fund addiction treatment services and mental health treatment adequately to serve everyone in supportive housing who seeks help?
How will proposed supportive housing stand up to NIMBY opposition from neighbors?
How should housing agencies handle residents who continue to use illegal drugs? What if the residents who continue to drink or use drugs have children living with them?
How will service agencies decide who will qualify for supportive housing? The available housing units aren’t likely to accommodate more than a fraction of the people in need.
Education, income, and social status appear to shape health in a complex web of interactions. Habits such as smoking, inactivity, poor diet and substance abuse are more prevalent among people in disadvantaged social groups, and probably account for much of the health gap between people of different social classes.
But behavior is not just a matter of personal choices. People are buffeted by social, cultural, and economic forces that can strongly influence behavior. In some disadvantaged neighborhoods, for example, tobacco and liquor advertising is prominent, lack of safe or convenient parks discourages outdoor recreation and much of the affordable food offered for sale is unhealthy.
Educational opportunity and achievement are especially powerful influences. Adults without a high school diploma, for example, are three times more likely to smoke than college graduates. Lesser education correlates with many other unhealthy behaviors. Education acts in at least two ways: It equips people with knowledge and skills useful for prevention of disease, and it paves the way to secure employment, a decent income and higher social status.
The physical environment and social quality of neighborhoods are important variables. People in lower-income and minority neighborhoods are likely to face more environmental health risks, such as hazardous waste sites and air pollution from nearby factories and highways. Such neighborhoods may lack social cohesion, undermining residents’ sense of security and well-being. Living in a neighborhood with high unemployment, urban blight and crime imposes a burden of chronic stress.
Prolonged exposure to stress can trigger the release of hormones, such as cortisol and epinephrine, that undermine immunity, boost inflammation and increase vulnerability to conditions such as diabetes and heart disease. Stress during fetal development, from a mother’s poor diet or exposure to pollutants, for example, may set the stage for diseases decades later in life by altering metabolism or triggering lasting changes in the activity of genes. Some studies suggest that these “epigenetic” changes in gene expression can be passed on to children and influence the occurrence of disease in more than one generation.
The 2007-2009 economic recession and its slow rebound has drawn new attention to the gaps between the so-called haves and the have-nots, a financial gap also known as income inequality.
Such wealth gaps have been growing for years, but a year-end report by the Pew Research Center showed that the difference in the United States is wider than ever. Researchers in a December 2014 analysis found the spread between America’s top earners and the middle class at a 30-year high, with median earnings among high-income Americans of $639,400 compared to $96,500 among those with more middle incomes. Based on data collected by the U.S. Federal Reserve, Pew’s researchers also found that the wealth gap actually increased in the years following the official end to the recession.
Worldwide, income inequality – sometimes referred to as economic inequality has also spread in recent decades. According to the Organisation for Economic Co-operation and Development, while levels of the wealth gap vary considerably across its member countries, such inequality overall has grow “moderately” since the mid-1980s. Some of the countries with the greatest discrepancy between the rich and the poor are Chile, Mexico and Turkey, the OECD found in a 2011 report. The United States came in fourth. Countries with the least gap included Slovenia, the Slovak Republic and the Czech Republic as well as the Nordic countries of Denmark, Norway, Sweden and Finland.
The economic impact of a wide gap between those with low-incomes and higher incomes, including its effects on employment rates and economic growth, are widely debated among policymakers and politicians alike. Meanwhile health researchers continue to examine the effects of wealth and poverty on longevity, obesity, overall wellness and a host of other areas.
Injuries and violence kill more young people in the U.S. than any other cause of death. The burden of these deaths varies enormously by race, ethnicity and social class. Deaths by homicide, for instance, are more than nine times more prevalent among blacks than among non-Hispanic whites, and homicide deaths are three times more common among American Indians and Alaskan Natives than among non-Hispanic whites under age 30:
Age-adjusted suicide and homicide deaths per 100,000 by race and ethnic origin in the year 2011 among those ages 0 to 29 in 17 states tracked in the CDC’s Web-based Injury Statistics Query and Reporting System (WISQARS).
Life expectancy numbers show that the unequal burden is stark. Homicide takes two full years off the expected life span of black males in Los Angeles County and homicide subtracts nearly five years from the expected life span of black males in some low-income urban areas of Los Angeles.
The most dangerous counties in the United States have violent death rates that are more than 10 times higher than the safest counties. As you can see in the map below, rates vary from less than 10 to more than 100 violent deaths per 100,000 population, based on homicides, police shootings, and suicides in the years 2004 through 2010. (Counties with rates based on 20 or fewer deaths are unreliable and are marked as suppressed.)
Credible evidence supports claims that the excess deaths are partly a consequence of the kind of society we have built, a society that marginalizes certain classes of people, depriving them of high-quality education, job opportunities, and healthy neighborhood living conditions. A Lancet paper, written by researchers from the Centers for Disease Control and Prevention, explains:
Young people growing up in communities with concentrated disadvantage are more likely to witness violence, attend underperforming schools, and have poor employment opportunities; they are also more likely to be exposed to drug-distribution networks and can access firearms more readily than can young people not growing up in such communities. These social and environmental factors can greatly increase an individual's risk of perpetrating violence and being a victim of violence. Thus, the link between socioeconomic status and injury is mediated by many conditions at home, at work, in communities, and within families and groups, with variations in effects noted across different types of injury. Social and economic factors fuel stress; challenge adaptation and coping mechanisms; contribute to social exclusion and isolation, residential instability, workplace pressures, and low community participation; and affect access to safe environments, safety equipment, and services. These factors can accumulate and interact to substantially affect experiences and risks.
Some research suggests that neighborhood environment largely explains the racial and socioeconomic differences in death rates. A study of homicide risk in Atlanta in the 1970s, for instance, found no differences in homicide by race when household crowding was used as a measure of neighborhood socioeconomic conditions. In a Los Angeles study published in 2010, 75 percent of the neighborhood variation in homicide’s impact on life expectancy could be predicted from neighborhood poverty levels.
Higher socioeconomic status may not protect the health of people who are well off when they live in poor environments. Regardless of your socioeconomic status, you are more likely to die of an injury if you live in an area with high poverty levels. The study that reached that conclusion found no link between individual social position and suicide, but a 50 percent increased risk of suicide for people living in neighborhoods with low socioeconomic status, high concentration of racial groups, and high residential and family instability.
Note how the risk of violent injury (and other injuries) rose with each step of decreasing neighborhood socioeconomic status in a ten-year study of hospitalizations in Memphis, Tenn., and surrounding Shelby County:
Some authorities say it might be best to target prevention efforts (e.g. public awareness campaigns, community policing, increased police patrols, collaborative involvement of neighborhood associations and local businesses) on high-risk neighborhoods, rather than diluting limited resources over a broader population or geographic area.
Others say that the U.S. needs to do more to confront the root causes of the inequality with strategies that reduce bias and discrimination and improve access to employment, safe housing, and high-quality education.
Cities such as Baltimore have tried to reduce the density of bars and liquor stores in high-crime neighborhoods because the density of alcohol outlets has been linked to higher rates of violent crime. The so-called Broken Windows theory has led to initiatives that try to reduce violence by restoring deteriorating neighborhoods, removing or securely sealing abandoned buildings, and greening vacant lots. The idea is that abandoned places give cover to criminal activity and signal that no one is in control.
Researchers in Philadelphia found a significant association between the risk of violent assault and the presence of abandoned buildings and vacant lots, even after controlling for demographic and socioeconomic characteristics of the neighborhoods. Vacant properties also had the strongest effect size, prevailing over almost a dozen well-known indicators of disadvantage. The following figure shows the link between rates of violent assault and the number of vacant properties across every census block group in Philadelphia County between 2002 and 2006:
The same group of investigators conducted a decade-long study of the impact of a vacant lot greening program in Philadelphia by comparing vacant lots that were converted into parks with matching lots that were left abandoned. They found that vacant lot greening was linked with consistent reductions in gun assaults. The impact on other types of crimes was less clear, however, and a smaller but more controlled trialfound less evidence of an effect.
Although not a typical medical “symptom,” a growing number of health care providers are taking a wider view when it comes to assessing health and one’s level of social support, recognizing that the lack of connections can lead to isolation and loneliness that can impact overall well-being.
A lack of social support structures can leave people isolated and feeling alone. Vulnerable groups can include the elderly, certain immigrants in certain areas, and others. In fact, one of the key factors that can determine one’s health and resilience is having a strong support network of people, whether they are family members or non-relatives, according to the American Psychological Association.
There are both psychological and physical impacts from loneliness, including aggression or social anxiety as well as sleep loss, changes in the brain, and elevated stress hormones. In modern society, the lack of social support has grown to become a public health concern as given ongoing changes to society and the way people live that stem from a variety of factors from technology and transportation to geography and family structures. Some studies also suggest there may be a genetic component to why being alone may weigh more on certain people.
In addition to mental and behavioral health effects, isolation can also impact physical fitness and nutrition, increasing the risk of a host of other related health conditions and disease from obesity and diabetes to hypertension.
"Isolation, lack of meaning and a loss of self-worth" all can impact health, according to former U.S. Surgeon General Vivek Murthy, adding that the “long-term emotional well-being that comes from fulfillment, purpose, connectedness and love” can impact people on a biological level.
“Happy people have lower levels of cortisol, a key stress hormone. They have more favorable heart rates and blood pressure. They have stronger immune systems, and they have lower levels of inflammatory markers” that have been linked to heart disease, Murthy said in a TedMed talk posted in 2016.
To combat such isolation, a growing number of communities are working with organizations to address potential isolation in people of all ages, from the elderly to younger adults and children.
“Whether we’re living with depression or diabetes, treatment is essential, too,” Murthy said, adding that how people process life events is a key contributor to long-term happiness, while changes in circumstances have mostly a short-term effect.
Researchers have urged patients and practitioners to should think of loneliness and well-being the same way as diet, exercise and sleep in addressing wellness.
Lesbian, gay, bisexual and transgender people, like other minority people, also face unique health challenges that can lead to disparities.
Experts, advocates and others also sometimes include “Q,” or queer or "questioning," making it LGBTQ, on the premise that for many people, especially youth, their sexual orientation and gender identity is something they are still sorting out. Others have pointed to sexuality as a spectrum and that for some how they identify themselves is fluid.
Someone’s sexual orientation, however they define themselves, can play a significant role in their health, increasing risks for certain conditions.
For example, LGBT individuals are at a higher risk for sexually transmitted diseases, including HIV, according to federal government data. While safer sex practices over the years have helped reduce infection rates for STDs, the Substance Abuse and Mental Health Services Administration (SAMHSA) noted that “studies over the last few years have demonstrated the return of many unsafe sex practices.” STD rates among gay men are a particular concern, with younger black and Hispanic gay men more likely to be infected with HIV, according to the Centers for Disease Control and Prevention.
Additionally, mental health issues are also a top concern. Despite some recent legal gains and public opinion polls showing a greater acceptance of LGBT individuals, many still face stigma in their families and communities that can lead to depression that in turn can increase the risk for substance abuse or suicide, research has shown. It can also manifest itself as eating disorders or, among younger people, trouble at school. Isolation can also make it harder to report abuse or assaults. Some also face homelessness.
Cancers can also be more common. For example, studies have shown misconceptions about lesbian and bisexual women’s risk for cervical cancer has led to fewer of them being screened for the disease. Their lower rate of oral contraceptive use and birth can also impact their risk for breast cancer. Additionally, among gay men, the human papillomavirus (HPV) may also be a factor in higher rates of anal cancer, according to SAMSHA, which added that the virus “is often downplayed as an unsightly inconvenience.”
Lack of health care coverage and access to care is also an issue. Until recently, LGBT individuals with no health insurance would not have been eligible to insurance through their partner’s employer. The Landmark Supreme Court ruling in June on gay marriage may change that. With marriage now legal, more partners could see coverage under their spouse’s health insurance paving the way for greater access to health care, including preventative care and screenings, consistent treatment for chronic diseases, and other health care.
Considered one of the world’s top 10 concerning chemicals, lead is a long-known risk still causing public health concerns.
Although lead exposure in the United States has declined in recent years, its pervasive and lingering effects in the environment continue persist, particularly among vulnerable populations. Its impact on children and their developing bodies, as well as pregnant women, is especially a concern.
“Despite significant progress in reducing geometric mean BLLs in recent decades, racial and income disparities persist. These observed differences can be traced to differences in housing quality, environmental conditions, nutrition, and other factors,” a CDC advisory panel wrote in a key 2012 report on the issue calling for action to reduce lead exposures.
The damaging health effects are well documented, especially lead exposure’s neurological impact. Lead exposure dramatically damages the brain and central nervous system, causing intellectual development delays and harming a range of other functions from memory to motor skills. Severe levels of exposure can cause coma or convulsions and can be fatal. But ongoing low levels of exposure are also a concern, in part because they may make it harder to detect and mitigate. The effects of lead exposure are not reversible, and there is no know safe level of lead exposure.
“Children at higher risk for lead exposure, are poor, are members of racial-ethnic minority groups, are recent immigrants, live in older, poorly maintained rental properties, or have parents who are exposed to lead at work,” according to the CDC. Symptoms of exposure build up over time and can include aggressive behavior, headaches and abdominal pain as well as loss of appetite. Children can also show development loss.
Although lead mitigation efforts exist to remove the material or reduce exposure, public health experts are also focused on prevention, in part by raising awareness about the hazards and risks. Housing is a particular concern. According to the CDC, one-third of U.S. dwellings still contain lead paint, mostly those built before 1978.
It also remains a major public health issues globally, particularly in developing countries. According to WHO, “developing regions” account for the “highest burden” of the 143,000 annual deaths worldwide from lead poisoning. Countries in Southeastern Asia account for half of such deaths while one-fifth occur in the Western Pacific nations such as chine. Another one-fifth occur in Eastern Mediterranean countries that include much of the Middle East.
In another example, WHO found that “exposure to lead-contaminated soil and dust resulting from battery recycling and mining has caused mass lead poisoning and multiple deaths in young children in Senegal and Nigeria.”
Life expectancy is a measure of likely mortality that weighs a number of factors across a population. In its simplest form, it is the average number of years an infant at birth could be expected to live. Put another way, it’s an overall look at the pattern across a certain group and the mortality rate across a population.
However, such projections are made with the idea that the current patterns of mortality will stay constant. Life expectancy is a hypothetical estimate of how long a baby will live if all factors at birth stay the same. Things change. And no one will really know long someone will live until they die. So researchers look at expectations and use statistics to extrapolate estimates.
And, of course, different groups have different life expectancies. On average, life expectancy in the United States is 78.8 years, according to the Centers for Disease Control and Prevention (CDC). Still, sex, race and location play a major role in how long one can expect to live, not to mention a host of other factors, such as access to health care and income.
There are a number of calculators that aim to show how long, on average, a certain individual could expect to live. Users plug in their gender, date of birth and other information. Many are aimed at financial planning and insurance but some, including Livingto100.com and Canada’s Project Big Life, take health information into account. The CDC, the Census Bureau and the World Bank also offer tables and estimates (see below).
Risk factors for a disease or health condition that can be modified make up so-called lifestyle risk, or controllable risk factors. Unlike uncontrollable risk factors, such as one’s genetic make-up, these risks are linked to behaviors such as diet and exercise that individuals can control.
According to the Centers for Disease Control and Prevention, such behaviors that are tied to the risk for disease, with lack of physical activity, poor nutrition, tobacco use and excessive alcohol consumption increasing the risk. This is particularly true when it comes to chronic diseases, which make up the bulk cause of deaths among Americans each year, the agency has said.
In 2015, researchers in Australia also identified two additional lifestyle risk factors: sedentary behavior and sleep. Overall, they studied six health behavior measures -- smoking, alcohol use, dietary behavior, physical inactivity, sedentary behavior, and sleep – “were associated with an increased risk for all-cause mortality.”
Lifestyle risk can play a role in the risk for a range of conditions from osteoporosis, cardiovascular disease and stroke to obesity, diabetes and even some cancers. For example, the CDC cites diets high in saturated fats, trans fat, cholesterol salt as a top risk factor for heart disease as well as other factors such as lack of physical activity, excess body fat, excessive alcohol consumption and tobacco use.
Just how controllable such risk factors are, however, is a matter of debate and a growing piece of the puzzle as public health experts examine ways to mitigate health disparities. While many focus on the behavior aspect, access is equally an issue. For example, if someone lives in an area with less access to sidewalks and green spaces as well as additional crime they may spend less time outdoors exercising.
Additionally, cost is another factor. Gym memberships and sporting equipment can help make it easier to get exercise. And if healthier foods such as fresh produce are more costly than mass-produced low-nutrition, high-calorie snacks, those with lower incomes are at a disadvantage. Such gaps can be addressed in part, through police – such as allowing SNAP benefits at farmers’ markets – but challenges remain an ample area of coverage.
This might not seem specific to social determinants of health, but machines that can be trained in health information may become gatekeepers of the future. If the artificial intelligence and medicine intersect successfully, the result could prove lifesaving for people whom social factors leave at a disadvantage. To grasp the importance, imagine living an hour or two-hour drive from the nearest emergency room or urgent care. How do you determine if a child with a fever or worrisome symptoms needs to be seen and that you should make the drive. A machine that has been trained on diagnostics could provide a step-by-step screen via a smartphone or online connection, helping with the decision-making.
Other potential uses of this technology include for triage in emergency rooms and urgent care or even for garden-variety telehealth. The questions that arise are whether or not all parties involved would give and receive the quality of care they’d otherwise experience, and of course, what margin of error exists for dangerous or potentially fatal mistakes.
The Patient-Centered Outcomes Research Institute has devoted a part of its website to addressing crucial issues in telehealth and the potential upsides and downsides. What the site does not yet dig into is how artificial intelligence will play into the delivery of telehealth, especially to underresourced populations. That’s in part because machine learning and AI are just now touching the realm of possibility when it comes to distance diagnostics.
A study published Feb. 11, 2019, in Nature Medicine offers a proof of concept, using electronic health records for thousands of children. Human doctors gleaned keywords from these records, researchers taught the terms to an AI system, and the system then chose from 55 possible options to diagnose from records for another 567,498 children. The accuracy of the process was quite high, 95 percent for the most common condition.
That’s a starting point. It remains to be seen where AI will go when it intersects with telehealth, but quite a few studies are in the works, and their results will be a turning point for health access. It’s definitely an area worth tracking for any health journalist.
Some of the social changes we’ve allowed – or even embraced – make it difficult for people to avoid unhealthy weight gain in the U.S. One of the most vivid demonstrations of our obesogenic environment is what happens among successive generations of immigrants: one recent study of Mexican immigrants found that the risk of becoming obese tripled by the second generation, relative to peers who remained in their native land.
Here are some of the environmental factors behind the rapid rise of obesity in the U.S. since the 1980s:
Food production & marketing Food companies spend over a billion dollars a year marketing nutrient-poor, calorie-dense convenience meals and snacks to children, producing measurable changes in food preferences and eating habits. U.S. Farm subsidies have boosted the output of nutrient poor, energy-dense food and pushed down the prices relative to healthier options. From 1985 to 2000, retail prices of fresh vegetables and fruit rose nearly 120 percent, about six times more than the rate of increase for soft drinks and three times more than that of sweets and fats.
Child development Obesity is the outcome of a process that can start in fetal development and infancy. An expectant mother’s severe undernourishment, or substantial overnourishment, can alter fetal metabolism and brain development, making offspring more prone to obesity, according to a number of animal and human studies. During infant development, observational studies have linked bottle-feeding rather than breast-feeding to weight gain. Lack of sleep, a trend affecting even toddlers, appears to promote obesity by disturbing the regulation of the hormones that drive appetite and the body's rate of energy use. In the Early Childhood Longitudinal Study, which tracked 7,738 kindergartners for a decade starting in 1998, half of the cases of obesity that arose were among kids who had become overweight during the preschool years.
Built environment Unsafe streets and lack of green space may be barriers to being physically active, although the evidence is limited. The effects of income and education may trump the influence of the built environment. It is clear that a lack of physical activity is one of the key factors in the worsening obesity gap between haves and have-nots. Children of college-educated parents have became more active than they were a decade ago, while children of less educated parents showed no improvement, according to a recent analysis.
Access to healthy food People living in lower income neighborhoods tend to be surrounded by less healthy offerings, i.e., fast food restaurants and corner stores selling convenience foods rather than green grocers and farmers’ markets selling fresh produce. Lower income neighborhoods may also be subject to a heavier barrage of advertising for unhealthy food and drink than higher income neighborhoods. To what extent “food deserts” drive obesity remains unclear. But the high price of healthy food does appear to be a significant driver of fattening food choices among families with limited incomes.
Living in poverty means living without the ability to afford or provide for a person’s basic needs.
“Human(s) needs include clean water, nutrition, health care, education, clothing, and shelter,” the Centers for Disease Control has said.
In 2014, 47 million people in the United States -- or nearly 15 percent of the nation’s population -- lived in poverty, the U.S. Census Bureau estimated. For a family of four that includes two children, the poverty threshold would be $24,008, according to the bureau. People can also move in and out of poverty over the course of a year.
Something else to consider is “deep poverty,” or those living with less than half the income cited for the poverty threshold. So that would be less than $12,004 for the two-adult, two-child family four. Of particular concern are the number of children living in such extreme poverty and the effects on their health and development.
Poverty can impact health, increasing the risk of infectious diseases and raising concerns about depression and other mental health issues as well as poor nutrition and food security. It can also make it harder to access preventive health care services or manage chronic diseases such as asthma, diabetes or heart disease. Lack of means also can lower life expectancy.
There can also be an indirect impact such as on health literacy. Poverty also ties in with behaviors that can affect health such as smoking and exercise or physical fitness. Environment –living in areas with poor air quality or lead paint – and stress also take their toll.
“Health in the United States is very strongly correlated with income,” researchers at the Institute for Research on Poverty at the University of Wisconsin-Madison have said. “Poor people are less healthy than those who are better off, whether the benchmark is mortality, the prevalence of acute or chronic diseases, or mental health.”
Life expectancy and mortality data reveal a complexity in the way race, ethnicity and gender combine to affect health risks. Compared to white Americans, African Americans and American Indians have higher death rates at every age from birth until advanced age. But black women have higher levels of life expectancy than white men at every age. Hispanics in the U.S. have lower mortality than whites at older ages. And Asians have lower mortality rates throughout life.
Racial disparities in health have persisted for decades – and in some cases worsened. Infant mortality for African Americans was 1.7 higher than for whites 1940, and despite steep reductions in infant deaths, the gap between blacks and whites has widened such that the rate among blacks was 2.4 times higher than whites as of 2006. In 1950, black and white Americans had comparable death rates for heart disease and cancer, but now death rates for both diseases are significantly higher among blacks.
Socioeconomic status Blacks and Hispanics have levels of overall poverty that are two to three times higher than those of whites. And socioeconomic inequalities have changed little over time, contrary to perception. But even after taking socioeconomic status into account, many disparities in health remain. A study comparing white physicians from Johns Hopkins University with black physicians from Meharry Medical College found large racial differences in health. Diabetes and hypertension were twice as high among the black doctors, who also had higher rates of heart disease than the white doctors.
“Weathering hypothesis” One cause of ethnic and racial disparities could be greater exposure to adverse social conditions and physical environments, which leads to greater wear and tear on physiological systems. Comparisons of infant death rates supply intriguing evidence to support this so-called “weathering hypothesis.” Among white and Mexican American women, infant mortality rates are lower for mothers who give birth in their twenties compared to those in their teens. But it’s the opposite for African American and Puerto Rican women in the U.S., who experience the lowest infant mortality as teenagers and higher infant mortality in their twenties, perhaps as a result of accumulated stress.
A revealing study compared African Americans and whites on measure called “allostatic load,” which is supposed to reflect how well or poorly the cardiovascular, metabolic, nervous, hormonal and immune systems are functioning. Scores are based on readings of blood pressure, body mass index, kidney function, blood sugar, cholesterol, C-reactive protein and other tests. The study found that blacks scored worse than whites at all ages, and the racial differences persisted after adjustment for poverty. In fact, nonpoor blacks scored worse than poor whites.
Racism Recent studies have found links between discrimination and health outcomes including sleep disturbance, abdominal fat, high blood sugar, coronary artery calcification, and breast cancer. Acceptance of negative stereotyping by stigmatized groups can be a source of anxieties that undermine social and psychological functioning. This so-called “internalized racism” has been linked to excessive drinking and psychological distress among African Americans. But as it stands, only a few studies have attempted to pin down the role of discrimination as a cause of health disparities.
Medical care Blacks in the United States are two to three times more likely than whites to have diabetes-related amputations, but blacks living in the U.K. face no higher risk than whites. Some experts believe that the near universal access to primary care in the U.K. accounts for the difference. There is evidence suggesting that prevention-oriented health care can help reduce disparities in health.
Costa Rica is an eye-opening case study. The country’s infant death rates fell from 60 per 1,000 live births in 1970 to 19 per 1,000 live births in 1985. Researchers attribute most of the improvement to public health programs, particularly the build up of primary health care in underserved areas in the 1970s. For each five years after primary care reform, child mortality fell by 13 percent, and adult mortality fell by 4 percent.
Experts in the field of social determinants of health tend to minimize the importance of medical care. (One widely quoted estimate asserts that medical care account for just 10 percent of potentially avoidable deaths.) But some research indicates that medical care may achieve bigger positive changes among socially disadvantaged populations than among the well-off.
Risk factors are conditions that can increase a person’s likelihood for developing a disease. But understanding the chances one has for getting sick – whether heart disease, cancer, dementia or a host of other conditions – is a complex calculation.
“A risk factor is any attribute, characteristic or exposure of an individual that increases the likelihood of developing a disease or injury,” according to the World Health Organization.
One part of the equation includes uncontrollable risk factors such as one’s gender or age that can impact their health. Race and ethnicity are another factor that can impact health that is out of a patient’s control. A person’s family history and DNA – i.e. their genetic make-up – also have an affect with little so far to realistically control for it.
Another part of the risk calculation, however, includes factors that in can be controlled.
These so-called controllable risk factors can those that can, at least in theory, be altered.
Some controllable risk factors are known as lifestyle risk and includes behaviors such as exercise and diet as well as alcohol and drug use. Those can have a significant factor in diseases such as obesity/overweight, cholesterol, diabetes, some cancers, stroke and cardiovascular disease.
But other factors that can also contribute to one’s health but are less easily changes such as geography. Where someone lives – whether by country, region or even down to a ZIP code – can make for stark differences in disease risk or longevity. While some people could easily move to a healthier area, others with fewer means may be less able. Additionally, contaminants in an area can also affect people’s health and is another area where, although it could be clean-up or remedied, may not easily materialize. In parts of the developing world, sanitation and clean water have a direct impact on health and can be modified, but not easily and note necessarily by an individual.
An individual’s overall risk factor weighs both things that can and cannot be modified to alter one’s health and wellness. Weighing such risk factors has an impact in a wide range of chronic diseases.
How well off financially a person is has an outsized role as well.
“Socioeconomic status is an important determinant of the likelihood that individuals and populations are exposed to environmental and other risk factors for health,” WHO researchers wrote in a 2004 report.
Nancy Adler, director of University of California, San Francisco’s Center for Health and Community, and Katherine Newman, dean of social sciences at Harvard’s Radcliffe Institute for Advanced Study, have also noted the impact of socioeconomic status (SES) on “three major determinants of health: health care, environmental exposure, and health behavior.”
“Inequality in education, income, and occupation exacerbates the gaps between the health “haves” and “have-nots,” Adler and Newman wrote for Health Affairs in 2002.
Since then, the impact of the social determinants on one’s risk factors, including behavioral risk, has become an increasing area of study.
For example, a University of California, Davis, study published in 2011 looked at the impact of socioeconomic status on heart disease. Other studies have looked at how SES affects the risk of other diseases such as cancer and diabetes as well as children/adolescent health and seniors.
The providing of health care and services in the nation’s more remote, nonurban areas, and the health status of the people living in those less-populated communities, is the core of rural health.
“Although a majority of counties are nonmetropolitan, the vast majority of the U.S. population resides in MSAs (metropolitan statistical areas),” according to the U.S. Centers for Disease Control and Prevention, which helps monitor rural health issues.
The 2010 Census found that less than 20 percent of people in the United States live in nonurban areas even as more than 95 percent of the nation’s land considered rural. From 2000 to 2010, rural U.S. residents “continued to decline as a percentage of the national population” While it remains to been seen if that trend will continue when the 2020 Census data emerges, the health implications remain. Residents also tend to be older and poorer, data show.
Distance is a major factor in rural health, with many residents living or working miles from available healthcare facilities. Delayed care not only plays a factor in emergency situations such as accidents or heart attacks when seconds count, it can also be a deterrent for those with chronic conditions who may face many trips to oversee their conditions or get medications. Most areas have few, if any, public transportation options.
Experts point to other social determinants, in particular housing, socioeconomic status and education, as major factors that can affect health care in less populated areas where access to jobs and other means may be more difficult. Mental illness, including addiction, is another challenge. Additionally, attracting and keeping health care providers willing to practice in country settings where they are paid less than their urban counterparts but often have to juggle more skill-sets can also be tough.
Overall, rural residents experience higher mortality rates and lower life expectancy than their urban counterparts, studies have shown. Researchers have found those in rural areas also suffer from higher rates of illnesses such as hypertension, diabetes and obesity/overweight, and are more likely to be hospitalized for something preventable, according to the Rural Assistance Center. Higher rates of smoking, alcohol use and other behaviors can also affect health in rural areas.
The perspective on disability can make a difference in how a story unfolds. One key distinction in perspectives on disability is whether or not it’s viewed as a social or a medical issue. Many disability-related websites define, compare and contrast the two. Briefly, the social model of disability posits that disability results from the outside, tracing to how society is structured. The implication is that changes in that structure, such as removal of both physical and cultural barriers, will level the playing field for people with disabilities and allow for independent function. The medical model frames disability as coming from the inside out. In this model, disability arises from some impairment or difference in the person that needs to be “repaired” or “fixed” so that the person can function independently.
Using the social model can frame a story in terms of what society could do to address inequities related to disability. Taking the medical model perspective centers the person and what needs to be “fixed” about them. Disability advocates argue that using the medical model imposes broad limitations because of a focus only on treating or resolving a physical problem. The social model, in contrast, opens up a variety of potential solutions through adjusting physical or cultural structures around the needs the disability creates.
The social support network for an individual can play a significant role on one’s health.
A social support network can consist of a range of trusted individuals from friends, immediate family or relatives, neighbors and other community members, or members of a church or other religious organization, as well as other groups. The American Psychological Association (APA) has said such a network need not be vast, and that even just a small number of trusted people can boost well-being.
Healthy People 2020, a federal government effort to boost the nation’s health by the year 2020, defines the areas of social influence that can impact health through four areas: social cohesion, civic participation, discrimination and incarceration.
Building a community surrounding can provide critical physical support such as driving someone to a medical appointment, helping deliver medicines or making a healthful mean, but also help pave the way for access to resources in the community such as exercise or other classes.
It can also deliver important emotional support.
“Though it may seem counterintuitive, having strong social support can actually make you more able to cope with problems on your own, by improving your self-esteem and sense of autonomy,” according to the APA. “Emotional support is an important protective factor for dealing with life’s difficulties … low levels of social support have even been linked to increased risk of death from cardiovascular disease, infectious diseases and cancer.”
Social norms and culture also play a role in health, and can be impacted by one’s network.
Having in place a strong network can be key to grappling with stress and trauma and boosting overall well-being. Researchers are also examining its affect on overall morbidity and mortality.
Experts at the Mayo Clinic advise that having access to supporters can not only ward off loneliness and creaet a sense of belonging, it also boosts feelings of security and self-confidence. Without it, people can face isolation and loneliness, an issue that a growing number of researchers are studying for its potential harms on health.
Psychologists at the University of Utah who reviewed available studies on the issue have noted that while findings have shown “ a robust relationship in which social and emotional support from others can be protective for health,” more detailed studies are needed.
Health studies routinely attempt to account for socioeconomic status, which is a person’s place in the hierarchy of wealth, self-determination, prestige and power. Socioeconomic status, or SES, is strongly linked to health and longevity. People higher on the SES ladder tend to live longer and healthier lives than people lower on the ladder. This link, the SES-health gradient, persists even among people in the middle and upper ranges of social position, many studies have shown.
To account for socioeconomic status, researchers typically rely on proxy measures such as years of education or household income. It’s convenient to do so, and sometimes no better data is available.
However, it’s important to keep in mind that proxy measures can obscure substantial socioeconomic differences.
Studies that compare people by househould income, for instance, are blind to potentially very large differences in wealth. Wealth, or total accumulated economic resources, is a stabilizing force that buffers families from the effects of setbacks such as unemployment or illness. People with comparable income can have drastically different wealth. Among very low income households, those headed by whites have about 400 times as much wealth as those headed by blacks. At higher income, whites have about 3 to 9 times the wealth of blacks.
Using years of education as a proxy can overlook meaningful differences in the quality of education. In some disadvantaged neighborhoods and cities, the quality of public schools is drastically worse than average. Also, years of education is definitely not a reliable stand-in for income or wealth. In the U.S., for example, black adults with 12 years of schooling earn 33 percent less, on average, than white adults with the same level of education, while Mexican-Americans earn 18 percent less than whites. Racial and ethnic disparities in income persist at every level of educational attainment, possbily as a result of unequal employment opportunities and differences in educational quality.
One-time measures of socioeconomic status ignore the effect of past experiences. Socioeconomic status can change over the course of a life, and past episodes of poverty or dramatic loss of income can have long-lasting effects on health. Deprivation during fetal development and early childhood, for example, can increase vulnerabilty to disease decades later.
Focusing on proxy measures of individuals may fail to register the influence of the different neighborhoods where people live. The characteristics of the built environment and social fabric of a neighborhood are powerful enough to shape health above and beyond the individual’s socioeconomic status.
In an informative review article worth reading in its entirety, Dr. Paula Braveman and colleagues distilled some useful conclusions about difficulties of accounting for socioeconomic status:
• Proxy measures of socioeconomic status are not interchangeable.
• Proxy measures can miss important and relevant aspects of socioeconomic status, and even studies that include multiple measures cannot capture all of the potentially important socioeconomic influences on health.
• A given proxy measure may have different meanings depending on the race, ethnicity, age, sex, or neighborhood environment of the people being considered.
• Racial and ethnic health disparities are likely to reflect unmeasured socioeconomic differences. (But that doesn’t mean that racial and ethnic disparities are reducible to socioeconomic issues; discrimination may also be an active force.)
The body’s response to challenges can cause stress, releasing hormones to grapple with it and triggering both mental and physical responses. Symptoms can manifest in a range of ways from breathing issues such as shortness of breath and digestive woes such as nausea to sleep problems and headaches. Stress can also affect moods, causing irritability, anxiety and even depression. Indirectly, it can also lead to other problems if people “self-medicate” with inactivity, smoking, drug use, overeating or other behaviors that can trigger other health complications.
Short-term, stress can be beneficial, providing the “fight or flight” response needed to duck out of danger or make it through a public presentation. But longer term stress presents health challenges that scientists are still trying to completely unravel, especially when it comes to “toxic” stress, youth and development as well as other related issues such as poverty, racism and other challenges.
But over time, chronic or long-term stress can take a toll.
“With chronic stress, those same life-saving responses in your body can suppress immune, digestive, sleep, and reproductive systems, which may cause them to stop working normally,” according to National Institutes of Health experts. “Over time, continued strain on your body from routine stress may contribute to serious health problems, such as heart disease, high blood pressure, diabetes, and other illnesses, as well as mental disorders like depression or anxiety.”
Such extended exposure to stress can unleash cortisol, epinephrine and other hormones can make people more vulnerable to everything from common virus to more serious conditions such as heart disease. Hormones released under stress can increase inflammation in the body and undermine its immune system. (Need a walk-through? HuffPost has this infographic.) The build-up of repeated stressful experiences over time is known as allostatic load, which psychologists try to measure as an indication of the accumulated effects of stress.
The impact of stress can be particular cause for concern in pregnant women and children, especially when it is severe and sustained over time. Known as toxic, or acute, stress, it can disrupt healthy development of the brain and organ systems, especially in the absence of any strong support systems or relationships, according to experts at Harvard University’s Center on the Developing Child.
“When toxic stress response occurs continually, or is triggered by multiple sources, it can have a cumulative toll on an individual’s physical and mental health—for a lifetime. The more adverse experiences in childhood, the greater the likelihood of developmental delays and later health problems, including heart disease, diabetes, substance abuse, and depression,” they wrote.
Stress and social determinants are intertwined. Examples of conditions that could cause longer-term health issues include unsafe living conditions, physical or emotional abuse, unemployment, illegal drug use, violence or neglect, among others.
At the same time, scientists are trying to further understand why the same stressors can impact people differently, leading some individuals to be more resilient than others, and whether resiliency to stressful triggers can be developed. How healthy one already is also likely plays a role.
“Acute stress responses in young, healthy individuals may be adaptive and typically do not impose a health burden,” researchers at the University of Miami’s Department of Psychology wrote, noting that people “who are optimistic and have good coping responses may benefit from such experiences and do well dealing with chronic stressor.”
“In contrast, if stressors are too strong and too persistent in individuals who are biologically vulnerable because of age, genetic, or constitutional factors, stressors may lead to disease. This is particularly the case if the person has few psychosocial resources and poor coping skills,” they added.
The effects of stress has also come into focus with increased attention on mental health issues and access to care under the 2010 Affordable Care Act in the face of more recent health care reform efforts. Besides physical changes in the body, stress over time can lead to depression and anxiety.
Health and health care delivery to a greater concentration of people in more densely populated areas underlies urban health. Key areas range from injuries and violence to infectious diseases and infrastructure.
“The factors influencing urban health include urban governance; population characteristics; the natural and built environment; social and economic development; services and health emergency management; and food security,” according to the World Health Organization.
In the United States, the bulk of the population lives in cities. More than 80 percent of U.S. residents live in metropolitan areas, even though such areas make up less than 5 percent of the country, according to the 2010 Census.
“While cities can bring opportunities, they can also bring challenges for better health,” WHO has said. Some of those challenges include access to healthy food, increased pollution, lack of affordable or safe housing. While many of the same social determinants that can affect health in rural areas also affect cities, they often play out in much different ways. For example, while rural residents may face challenges due to a lack of available transportation, urban dwellers may have public transportation nearby but be unable to afford it. Similarly, while rural hospitals may have trouble keeping their doors open, cities may have many hospitals but mostly clustered in wealthier neighborhoods.
Wearables: Wearables are becoming increasingly popular and are set to be a major health tool (and profit boom), with major tech companies entering the race. The wearables getting the most attention as of this writing are wrist versions that can detect atrial fibrillation or hypertension. Others are focused on aspects of fitness, allowing users to track activity, diet, heart rate, sleep and more. Government is interested, as well, with the National Institutes of Health having awarded millions for the development of wearable-based health tools.
What does this have to do with social determinants of health? Primarily, access related to costs. The cost of the fitness versions can be upwards of $400, while one that tracks hypertension has a price point of $350 as of this writing. As with all healthcare costs, greater expense means less access for many people who might need it most. Socioeconomics is the crossroads where medication costs, stress and health intersect: people who are asked to buy medication for a condition that they cannot feel or see may well make that expense a low priority over more urgent and apparent needs. So adherence drops and their condition persists or progresses.
But a wearable that could apprise them on a regular basis in visible numbers of how their medication is helping might change that calculus for them. And that, of course, takes things full circle back to the question of how people with socioeconomic barriers to access would ever acquire a wearable that could give them such useful, straightforward information.
That leads to the flip side of wearables: if they can be made accessible to most people, their potential for people with access barriers could be huge. They could allow remote monitoring for patients who live far from care centers or struggle to make the trip to one for regular appointments. They can mitigate the very factors that create other obstacles to effective care, including improving adherence and giving the user ownership of their healthcare. In the end, they could even reduce costs—if only people can afford them.
This Janus-faced problem of wearables as they relate to the social determinants of health is one to watch from many angles. How will they help, and whom? How will they harm?–privacy is a huge concern, and if they become widely used, social determinants may influence whose privacy is most exploited; in contrast, they also serve as an electronic health record, which could be a help. Will they remain just out of arm’s reach for people who need them most? Unseen but worth tracking is the future of these tools: which conditions they will target beyond existing wearables and those in the pipeline, the predicted cost trajectories—will they stay high or follow the arc of the microwave, which debuted with a $3000 price tag and now can cost under $100?