Your neighborhood, plus emotional stress, may be aging you prematurely

CHAMPAIGN, Ill. — While scientists have long known that living in a disadvantaged neighborhood is associated with biological symptoms of accelerated aging, emotional distress accounts for a significant portion of these effects, researchers found in a recent study.

“Consistent with a chains-of-risk framework — the theory that later-life health conditions are triggered by sequential, linked exposures earlier in life — the findings support our hypothesis that prolonged exposure to contextual socioeconomic disadvantage accelerates one’s biological age, and that some but not all of this effect operates through increases in psychological symptoms,” said first author Christina Kamis, a professor of sociology at the University of Illinois Urbana-Champaign.

The study’s sample population comprised more than 1,440 people living in Wisconsin and included two factors — cumulative exposure to neighborhood disadvantage and overall emotional distress — that prior studies have not explored. Co-author Wei Xu, a professor in the Institute for Health and Humanity at the Medical College of Wisconsin, has led a number of studies investigating links between health disparities and neighborhood conditions.

Published in The Journals of Gerontology, Series B: Psychological Sciences and Social Sciences, the paper was co-written by Michal Engelman, a sociology professor and the director of the Center for Demography of Health and Aging at the University of Wisconsin-Madison; and Kristen Malecki, a professor and the director of the Division of Environmental and Occupational Health Sciences at the University of Illinois Chicago School of Public Health.

Engelman and Malecki were the co-principal investigators for the Researching Epigenetics, Weathering, Aging and Residential Disadvantage project that contributed to this work. Funded by the National Institutes on Aging at the National Institutes of Health, the project links the residential histories of respondents of the Survey on the Health of Wisconsin to survey and biomarker data, examining the relationship between long-term exposure to residential disadvantage and DNA methylation patterns and metabolic outcomes. Malecki was the principal investigator of SHOW when the data were collected.

While much of the prior research on accelerated aging, neighborhood factors and residents’ emotions focused on depression, the current study also explored stress and anxiety, “and how each of the psychological factors mediated the relationship between cumulative exposure to neighborhood disadvantage and epigenetic aging,” Xu said. “What we found is that anxiety appeared to be a really significant mediator between exposure and the outcome.”

Kamis said the research used three epigenetic “clocks” that measure an individual’s state of biological aging based on patterns of epigenetic changes in the genome. “These epigenetic clocks have different algorithms and assumptions,” Kamis said. “If we’re seeing similar patterns across several different clocks, we have stronger evidence of the relationship.”

The team used two-second generation clocks, the PhenoAge and GrimAge, which, when regressed on chronological age, produce residuals indicating epigenetic age acceleration; along with the Dunedin Pace of Aging clock, which can be interpreted as the rate of biological aging per one year of chronological age, Kamis said.

While the team found that epigenetic age acceleration was common among those in the sample population, the magnitude varied depending on the clock, Kamis said. By the Dunedin PACE, more than 60% of the participants were aging faster than expected; however, the PhenoAge and GrimAge clocks   indicated that 46% and 42%, respectively, of those in the sample were affected.

Six census-tract socioeconomic indicators — including median household income, the percentage of rental households and the proportions of residents with a high school education or less — were used to characterize neighborhood disadvantage.

The researchers also created a composite measure of cumulative exposure by tracking each individual’s residential history since the age of 18 — a unique level of exposure that prior neighborhood-biological aging research has rarely been able to consider due to data limitations, Kamis said.

The team obtained participants’ residential data for up to five decades, Xu said. “That allowed us to make more accurate inferences about the relationship between neighborhood disadvantage and biological aging, as well as the role of psychological symptoms in that relationship, because we accounted for their cumulative life course exposure, not just that associated with their current neighborhood.”

Individuals’ psychological symptoms were measured using a 21-item scale that included three subscales that separately assessed depression, anxiety and stress. By clinical measures, about 24% of the individuals in the study had above-normal scores for depression, while 21% had elevated levels of anxiety and 15% had above-normal stress scores, the researchers found. By adding each person’s scores on the three subscales together, the team calculated a composite measure called “overall distress.”

Cumulative neighborhood disadvantage was a significant predictor of greater overall distress across all three models, and it predicted accelerated aging across all three clocks directly and indirectly through increases in distress, Kamis said.

“Cumulative neighborhood disadvantage and overall distress were both significant predictors of accelerated aging for all three clocks,” Kamis said. “One-unit increases in cumulative disadvantage were associated with .187 and .219 additional years of age acceleration by the PhenoAge and GrimAge clocks, respectively, and a .006 increase in the pace of aging by the Dunedin PACE.”

For each accelerated epigenetic aging measure, cumulative neighborhood disadvantage had both a significant direct and indirect effect through overall distress, Kamis said. “About 13% of the effect of neighborhood disadvantage operated through overall distress by the GrimAge clock, while that proportion was around 10% for each of the other two clocks.

“When we looked at each of the psychological symptom subscales separately, most of the indirect effect on accelerated aging occurred through anxiety,” Kamis said.

Amy Schultz, a scientist at the UW-Madison School of Medicine and Public Health, and then-postdoctoral scholar Joseph Clark also were co-authors of the current study.