The researchers did not observe a significant increase between the neighborhoods in fruit and vegetable intake, whole grain consumption, or body mass index. Though the introduction of supermarkets in food deserts is appropriate, the mechanisms for understanding how the introduction of such supermarkets may influence dietary behaviors and weight status requires further study. Policymakers considering the approach of introducing full‐service supermarkets in food deserts should include assessments of other community‐level mechanisms that may affect both store users and nonusers. Finally, future assessments should consider longer‐term follow‐ups, which may allow for changes in weight status to be detected [29].
Another PHRESH study examined neighborhood walkability. Previous studies have found that Black adults are not likely to get the recommended amount of daily moderate to vigorous physical activity (MVPA) [30], which is known to be an important factor for lowering diastolic blood pressure [31] and for reducing the risk of cardiovascular disease and risk factors [32]. In a study conducted by Richardson and colleagues using data from the PHRESH study, it was hypothesized that low levels of MVPA (where accelerometry was used to measure physical activity, which is superior to self‐reporting) among Black adults may be associated with crime rates, the amount of green space, and walkability in one's neighborhood [30]. In addition to data from PHRESH, the study examined crime data available from the City of Pittsburgh and used ArcGIS to calculate street network distances from households to crime locations. The team hypothesized that crime occurring in the previous year would influence perceptions of safety. The team studied the relationship between these three variables (i.e., neighborhood green space, walkability, and crime) and their influence on MVPA, as well as a potential interaction effect.
The results suggested that, although all residents engaged in little MVPA, women under the age of 65 living in more walkable neighborhoods engaged in significantly more MVPA. The variables green space and crime were not associated with MVPA in this study. However, there may have been limited power to detect associations between neighborhood characteristics and MVPA. Future studies are required to increase knowledge regarding the impact of lifestyle and neighborhood factors (e.g., walkability, green space, and crime) and their interactions on MVPA to inform public health policy [30].
3.6 Challenges and Future Opportunities
3.6.1 Biological Links to Social Determinants
One of the major challenges that researchers face is understanding how the social determinants of health get “under the skin” to impact health. This requires studies to link specific social determinants of health to biological mechanisms. Several developing research areas aim to investigate such links as epigenetic markers, and how heritable and potentially modifiable changes in gene expression can be affected by nonbiological and environmental exposures [33]. Other examples include biological markers of stress, such as cortisol or telomere length, as a marker for cellular aging. These issues will add to the ongoing complexity of health disparities research. Nonetheless, continuing to develop new methods to elucidate mechanisms will be crucial in the quest to eliminate health disparities.
3.7 Summary
This chapter focused on summarizing the state of the literature, measurement issues, and research opportunities related to race, SES, and other social determinants. The chapter references two conceptual frameworks in order to provide an understanding of the factors involved in the relationships between race/ethnicity, SES behavioral mediators/moderators, and health outcomes. The use of widely accepted measures, such as those used by the US Census Bureau, is critical to minority health and health disparities research because they make it possible to compare findings across studies and over time.
The differences between race and ethnicity are distinct, although they can be difficult to distinguish if one is not intimately familiar with them. As the United States becomes more diverse, future health research will need to disaggregate the larger racial/ethnic categories to understand the causes of known differences in health status, behaviors, and outcomes between subgroups. Among the key measures of health are mortality, morbidity, and life expectancy, which can be used to gauge progress in improving minority health and in reducing health disparities.
One of the most studied social determinants, SES, is a strong predictor of health and can be measured on an individual or community/neighborhood level. Other social determinants, including acculturation, social environment, and physical environment, can also influence health independent of SES. Assessing such factors, in addition to SES, can elucidate relationships that have previously gone unobserved. The examples above represent some of the leading research related to race, ethnicity, and social determinants of health.
In addition to disaggregating racial/ethnic groups, the opportunity to link social determinants of health to biological mechanisms will advance research addressing minority health and health disparities. Future research should also consider integrating race/ethnicity, SES, and other social determinants into the healthcare setting, as well as into the emerging areas of precision medicine, clinical trials, sexual and gender minority research, and workforce diversity.
3.8 Key Points
Race and ethnicity are complex constructs and incorporate aspects of skin color, societal influences, nationality, and culture, which all impact racial/ethnic differences in health status.
Racial/ethnic minority populations in the United States experience significant morbidity, mortality, and decreased life expectancy compared to the White population.
Lower SES, income inequality, and other factors such as poorer physical and social environments are social determinants that impact health, particularly for racial/ethnic minority groups.
Several innovative studies have been designed and conducted, especially to understand complex issues in health disparities research and intricate aspects of the culture and life of racial/ethnic populations.
More research is needed to link the social determinants of health to biological mechanisms and to understand the nuances of social determinants in understudied and under‐served populations.
Disclaimer
The views and opinions expressed in this chapter are those of the authors only and do not necessarily represent the views, official policy, or position of the U.S. Department of Health and Human Services or any of its affiliated institutions or agencies.
References
1 1 Marmot, M., Friel, S., Bell, R. et al. (2008). Closing the gap in a generation: health equity through action on the social determinants of health. The Lancet 372 (9650): 1661–1669.
2 2 Marmot, M. and Allen, J.J. (2014). Social Determinants of Health Equity. American Journal of Public Health 104 (Suppl4): S517–S519.
3 3 LaVeist, T.A. (2005). Conceptual issues in race/ethnicity and health. In: Minority Populations and Health, 15–29. San Francisco, CA: Jossey‐Bass.
4 4 Houghton Mifflin Harcourt Publishing Company (2017). American Heritage Dictionary of the English Language, 5e. Boston, MA: Houghton Mifflin Harcourt.
5 5 LaVeist‐Ramos, T.A., Galarraga, J., Thorpe, R.J. et al. (2012). Are black Hispanics black or Hispanic? Exploring disparities at the intersection of race and ethnicity. Journal of Epidemiology and Community Health 66 (7): e21.
6 6 National Center for Health Statistics (2016). Health, United States, 2015: With Special Feature on Racial and Ethnic Health Disparities. Hyattsville, MD: National Center for Health Statistics.
7 7 Gardner, J.W. and Sanborn, J.S. (1990). Years of potential life lost (YPLL) – what does it measure? Epidemiology 1 (4): 322–329.
8 8 Xu, J., Murphy, S.L., Kochanek, K.D., and Arias, E. (2016). Mortality in the United States, 2015. Hyattsville, MD: National Center