A new study illustrates the extent to which poverty impacts health: individuals in households with annual incomes below $15,000 are at three times the risk for early death compared to those in average-income families.
The research, led by Vanderbilt University Medical Center and published in the American Journal of Preventive Medicine, was based on a racially diverse low-income population.
It also shows that a healthy lifestyle may partially mitigate the effects of poverty on death rates, said senior author Wei Zheng, M.D., Ph.D., M.P.H., director of the Vanderbilt Epidemiology Center and chief of the Division of Epidemiology at VUMC.
“If you maintain a healthy lifestyle, you can improve your health and reduce your chances of dying, no matter what your household income is,” Zheng said.
Gathering the Evidence
Zheng and colleagues analyzed data from the Southern Community Cohort Study, which included 79,385 participants, ages 40 to 79 years.
The majority of research participants were recruited at community health centers in 12 Southeastern states between 2002 and 2009. About two thirds were Black. One quarter lived in rural areas and three quarters in urban areas. More than half –
55 percent – had an annual household income of less than $15,000 per year.
“This is a unique study because it was conducted primarily in a very low-income population,” Zheng said.
The low-income group was compared to those with a household income of about $50,000, which is approximately the national average.
“We found an alarming 3.3 times higher risk of death in the low-income group compared to the high-income group,” he said.
Participants completed questionnaires that collected data about their health, lifestyle and behavioral factors associated with disease and death, including cigarette smoking, alcohol consumption, physical activity and diet quality. Each participant received a lifestyle score based on risk factors identified in the questionnaire.
To put the findings in perspective, Zheng noted: “Tobacco smoking is the leading cause of death in the United States. The impact of poverty on the risk of death is even higher in magnitude than tobacco smoking in this study population.”
“The impact of poverty on the risk of death is even higher in magnitude than tobacco smoking in this population.”
Healthy Lifestyles Matter
Reassuringly, a healthy lifestyle appeared to be protective. Low-income participants with the best lifestyle scores had a lower cumulative death rate than those in the high-income group with the worst lifestyle scores.
Those in the low-income group with the worst lifestyle score had a more than six-fold increase in death when compared to those in the higher-income group with top lifestyle scores. Yet, people living below the poverty level face tough challenges in sustaining a healthy lifestyle.
“They have limited availability to healthy food choices and less access to health care or to safe outdoor environments conducive to regular physical exercise,” Zheng said.
White participants in the high-income group had a lower cumulative risk of death than Black participants in the same income group, but the reasons were not explored in this study. The situation was reversed in the low-income group – white participants had a higher cumulative death rate than Black participants with lower incomes.
The high-income group registered an average age at death of 82.7 years for white participants and 81.2 years for Black participants. In the lower-income group, the average age at death was 67.8 years for white participants and 70.9 years for Black participants – resulting in a difference of more than 10 years in life expectancy associated with poverty.
Poor communities need better information about what a healthy lifestyle means, Zheng said.
“Many poor people get their health care through community networks. We need to work with community health centers to raise awareness on how adopting a healthy lifestyle can improve health,” he said.
Doctors can also play a role by talking to patients about lifestyle factors.
“Doctors need to emphasize the importance of healthy behaviors. Patients are more likely to believe health information when they hear it from their doctor,” Zheng said.
