Each year, the CDC tracks the diseases that kill the most people in the United States (the frontrunner for now: heart disease). But diseases don’t happen in a vacuum – society often shapes who suffers from certain illnesses, even if we can't identify them on a death certificate.
A new study gives a clearer picture of the social undercurrents that shape death: It lists tge 10 life experiences that were linked to death over the course of the study, and which groups are more likely to experience each one.
In a sample of 13,611 people from the US Health and Retirement Study, scientists identified 57 different non-biological factors linked to death over 6 years. These 57 factors primarily fell into six categories: factors related to hardship in childhood (like low educational attainment for parents), low socioeconomic status, health behaviors (like smoking), negative social interactions (like divorce), or and adverse events during adulthood (like discrimination).
The team determined how strongly all of these factors were linked to death by cataloging how likely it was that someone who experienced each of these factors died over the course of six years. Their analysis yielded a ranked list, and here are the top 10:
- Being a smoker– increased risk by 91 percent.
- A history of divorce – increased risk by 45 percent.
- Abusing alcohol – increased risk by 36 percent.
- Recent financial difficulties – increased risk by 32 percent.
- A history of unemployment – increased risk by 32 percent.
- A history of smoking– increased risk by 32 percent.
- Lower life satisfaction – increased risk by 31 percent.
- Never getting married – increased risk by 30 percent.
- A history of food stamp use – increased risk by 28 percent.
- Seeing the negative side of everything – increased risk by 23 percent.
The study was published Monday in Proceedings of the National Academy of Sciences.
Who is most likely to experience these factors? – The story of this study extends far beyond the top 10. For instance, ranking in at number 13 was daily discrimination. Discrimination was associated with an 22 percent increase in risk of death over the study period.
Importantly, 77.6 of the study population was white, which is a nationally representative sample, the authors note. But breaking the data down by race revealed clear inequities. They found that Black people were 22 percent more likely to have experienced one of these factors linked with death over the study period in the first place. In regard to gender, men were 28 percent more likely to have experiences these conditions compared to women.
The study adjusts for race, gender, and whether someone was foreign born to arrive at the list of factors, so the findings are intended to apply across all groups. But the fact that race and gender were linked with higher risks with is noteworthy in itself.
The study’s lead author, Eli Puterman, tells Inverse that the population in the study was mostly white, but that they weighted the sample to best reflect the demographics of older Americans. He adds that their followup analysis “did not reveal differences in the impact of discrimination between the participants who identified as white and those who did not.”
The ripple effects of discrimination, which stem from systemic racism, however, may not be always labeled as such, adds Puterman.
“Considering the current climate, daily experiences of discrimination is one part of the lived experience of minorities, but systemic racism plays a significant role in shaping the schools we can attend, the careers we dream of having, the behaviors we engage in, and so on, and we did capture discrimination in this way,” Puterman says.
Stress and mortality– Some of the conditions on this list of factors have more intuitive links to mortality than others. Smoking is the leading risk factor for lung cancer, and is linked to numerous health problems. Alcohol abuse has also been linked to higher mortality in past work.
The connection between socioeconomic and social factors and stress can be indirect – these factors influence access to care, and exposure to environmental factors. But there's also a biological explanation for how these social forces impact health. The mechanism that underpins them is stress, Puterman says.
Stress activates two major systems in the body. The first is the sympathetic-adrenal medullary pathway, which releases adrenaline when you’re under duress. The second is the hypothalamic-pituitary-adrenal axis, which triggers the release of cortisol, another stress hormone.
“In the long term, continued activation of these systems can cause low-grade inflammation and increased heart rate and blood pressure – to name a few outcomes of these systems when activated for too long,” says Puterman.
Moving forward – In the future, the authors argue that studies need to take into account the social factors that might shape longevity. While we search for biological ways to extend our lives, there are social solutions, too.
“Expanding our ideas of what types of factors are associated with disease and mortality can perhaps lead to testing causality and developing interventions and shaping policy down the road,” says Puterman.
As the authors note in the paper, that includes thinking about “macro-level markers” that might underpin something like stressful childhood, or food or financial insecurity. That includes structural racism.
Ultimately, these experiences don’t only affect the world outside your body, they can linger on the inside too.
Abstract: Behavioral and social scientists have identified many nonbiological predictors of mortality. An important limitation of much of this research, however, is that risk factors are not studied in comparison with one another or from across different fields of research. It therefore remains unclear which factors should be prioritized for interventions and policy to reduce mortality risk. In the current investigation, we compare 57 factors within a multidisciplinary framework. These include (i) adverse socioeconomic and psychosocial experiences during child- hood and (ii) socioeconomic conditions, (iii) health behaviors, (iv) social connections, (v) psychological characteristics, and (vi) adverse experiences during adulthood. The current prospective cohort investigation with 13,611 adults from 52 to 104 y of age (mean age 69.3 y) from the nationally representative Health and Retirement Study used weighted traditional (i.e., multivariate Cox regressions) and machine-learning (i.e., lasso, random forest analysis) statistical approaches to identify the leading predictors of mortality over 6 y of follow-up time. We demonstrate that, in addition to the well-established behavioral risk factors of smoking, alcohol abuse, and lack of physical activity, economic (e.g., recent financial difficulties, unemployment history), social (e.g., childhood adversity, divorce history), and psychological (e.g., negative affectivity) factors were also among the strongest predictors of mortality among older American adults. The strength of these predictors should be used to guide future transdisciplinary investigations and intervention studies across the fields of epidemiology, psychology, sociology, economics, and medicine to understand how changes in these factors alter individual mortality risk.