Sustained economic hardship among young people is strongly linked to poor cognitive function in midlife and may contribute to premature aging, according to a new study in the American Journal of Preventive Medicine.
Although previous research has shown that exposure to poor socioeconomic conditions during childhood and/or adulthood is associated with cognitive deficits, most of these studies involved older adults, offering little data on whether poverty can influence cognitive health earlier in life.
“Income is dynamic and individuals are likely to experience income changes and mobility especially between young adulthood and midlife,” said lead investigator Adina Zeki Al Hazzouri, Ph.D., of the Division of Epidemiology, Department of Public Health Sciences at the University of Miami.
“Monitoring changes in income and financial difficulty over an extended period of time and how these influence cognitive health is of great public health interest.”
The researchers investigated the effects of sustained poverty and perceived financial difficulty on cognitive function in midlife using income data for about 3,400 adults who took part in the ongoing Coronary Artery Risk Development in Young Adults (CARDIA) prospective cohort study. The CARDIA study tracked black and white males and females 18 to 30 years of age at the start of the study in 1985-86.
Income information was gathered from study participants six times between 1985 and 2010. Sustained poverty was defined as the percentage of time the participants’ household income was less than 200 percent of the federal poverty level.
Participants were divided into four groups: never in poverty; less than a third of the time; from third to nearly 100 percent of the time; or always in poverty. The annual income cut-offs for 200 percent of the federal poverty level for a four-person household were $26,718 in 1990, $28,670 in 1992, $31,138 in 1995, $35,206 in 2000, $39,942 in 2005, and $44,630 in 2010.
In 2010, at a mean age of 50 years, participants underwent a series of tests that are widely used and considered reliable to detect cognitive aging. The findings show significant and graded associations between greater exposure to economic hardship and worse cognitive function, suggesting that poverty and perceived hardship may be important contributors to cognitive aging.
People living in chronic poverty scored significantly worse than individuals never in poverty. Similar results were found in individuals with perceived financial difficulty.
“Maintaining cognitive abilities is a key component of health,” said Zeki Al Hazzouri. “Findings among this relatively young cohort place economic hardship as being on the pathway to cognitive aging and as an important contributor to premature aging among economically disadvantaged populations. It is important to monitor how trends in income and other social and economic parameters influence health outcomes.”