New Study Shows the Dramatic Impact of Extreme Poverty on Mortality in a Racially Diverse Low-Income Population

During the past 40 years, the gap between rich and poor Americans has continued to widen in terms of health and mortality, as well as income.

Now, in a first-of-its-kind study(opens in new tab/window) of an extremely low-income and predominantly Black population, researchers at Vanderbilt University Medical Center found that people who earned less than $15,000 a year died, on average, more than 10 years earlier than those whose annual income exceeded $50,000.

Addressing racial and income disparities in mortality requires a comprehensive approach. Ultimately, “efforts to improve income equality are crucial in reducing mortality and health disparities among low-income Americans,” the researchers reported recently in the American Journal of Preventive Medicine(opens in new tab/window), published by Elsevier.

The paper’s corresponding author, Wei Zheng(opens in new tab/window), MD, PhD, MPH, director of the Vanderbilt Epidemiology Center, noted, “Tobacco smoking is the leading cause of death in the US. However, we found that in this low-income population excess risk of death due to poverty is greater in magnitude than tobacco smoking.”

The study included 79,385 participants aged 40 to 79 in the ongoing Southern Community Cohort Study(opens in new tab/window), the majority of whom were recruited at community health centers in 12 south-eastern states between 2002 and 2009. Approximately two thirds of cohort members are Black.

More than half of the study participants reported an annual household income of less than $15,000, providing a unique opportunity to evaluate the impact of extreme poverty on mortality in a racially diverse low-income population.

Participants completed questionnaires that collected data about their health and lifestyle/behavioral factors associated with disease risk and death, including cigarette smoking, alcohol consumption, physical activity, and the quality of the foods they ate.

The study analyzed 19,749 deaths in this group that occurred during a period of about 18 years from the time participants joined the cohort.

Individuals in the low-income group (less than $15,000 in annual income) who had the worst lifestyle score based on risk factors identified in the questionnaire, had a 6.1-fold increase in mortality, compared to those in the highest-income group (more than $50,000) who had the best lifestyle score.

Low-income participants with the best lifestyle scores had a lower cumulative mortality than those in the high-income group with the worst lifestyle scores, supporting the impact that behavioral and lifestyle factors have on health and lifespan.

Because low-income communities tend to have a limited availability of healthy food options and less access to healthcare or to safe, walkable environments that are conducive to regular physical exercise, encouraging healthy behaviors and lifestyles cannot fully mitigate the adverse effects of poverty on mortality, the researchers cautioned.

Among those in the high-income group, White participants had a lower cumulative mortality risk than Black participants. But the situation was reversed in the low-income group — Whites had a higher cumulative mortality than Blacks.

In the high-income group, the average age at death was 82.7 years for Whites and 81.2 years for Blacks. In the low-income group, the average age at death was 67.8 years for Whites and 70.9 years for Blacks.

Despite the healthier lifestyle practiced by some participants, the disparity in life expectancy between the two income groups ranged from about 10 years for Blacks to nearly 15 years for Whites.

The researchers concluded, “This estimate is alarming and calls for evaluation of policy and public health strategies to reduce mortality and health disparities in low-income Americans. Without interventions on this specific population to decouple low income and health, further widening and hardening SES (socioeconomic status) gaps might be seen in health.”

Notes for editors

The article is “Impacts of Poverty and Lifestyles on Mortality: A Cohort Study in Predominantly Low-Income Americans,” by Lili Liu, MPH, Wanqing Wen, MD, MPH, Martha J. Shrubsole, PhD, Loren E. Lipworth, ScD, Michael T. Mumma, MS, Brooke A. Ackerly, PhD, Xiao-Ou Shu, MD, PhD, William J. Blot, PhD, and Wei Zheng, MD, PhD, MPH (https://doi.org/10.1016/j.amepre.2024.02.015(opens in new tab/window)).It appears online in advance of the American Journal of Preventive Medicine, volume 67, issue 1 (July 2024), published by Elsevier.

The article is openly available for 30 days at https://www.ajpmonline.org/article/S0749-3797(24)00069-2/abstract(opens in new tab/window).

Full text of this article is also available to credentialed journalists upon request; contact Jillian B. Morgan at +1 734 936 1590 or [email protected](opens in new tab/window). Journalists wishing to interview the authors should contact Craig Boerner, Assistant Director, Media Director, National News Director, Vanderbilt University Medical Center, at +1 615 322 4747 or [email protected](opens in new tab/window).

Dr. Zheng is the Anne Potter Wilson Professor of Medicine, chief of the Division of Epidemiology in the Department of Medicine, and associate director for Population Sciences Research in the Vanderbilt-Ingram Cancer Center.

Lili Liu(opens in new tab/window), MPH, a graduate student in Epidemiology at VUMC, is the paper’s first author.

Vanderbilt University and VUMC co-authors are Wanqing Wen, MD, MPH, Martha Shrubsole, PhD, Loren E. Lipworth, ScD, Michael T. Mumma, MS, Brooke Ackerly, PhD, Xiao-Ou Shu, MD, PhD, and William J. Blot, PhD.

The research was supported in part by National Institutes of Health grant U01CA202979. The Southern Community Cohort Study is funded by the National Cancer Institute.

About the American Journal of Preventive Medicine

The American Journal of Preventive Medicine(opens in new tab/window) is the official journal of the American College of Preventive Medicine(opens in new tab/window) and the Association for Prevention Teaching and Research(opens in new tab/window). It publishes articles in the areas of prevention research, teaching, practice and policy. Original research is published on interventions aimed at the prevention of chronic and acute disease and the promotion of individual and community health. The journal features papers that address the primary and secondary prevention of important clinical, behavioral and public health issues such as injury and violence, infectious disease, women's health, smoking, sedentary behaviors and physical activity, nutrition, diabetes, obesity, and alcohol and drug abuse. Papers also address educational initiatives aimed at improving the ability of health professionals to provide effective clinical prevention and public health services. The journal also publishes official policy statements from the two co-sponsoring organizations, health services research pertinent to prevention and public health, review articles, media reviews, and editorials. www.ajpmonline.org(opens in new tab/window)

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