Is Political Polarization Becoming a Social Determinant of Health?
A new study published in Nature Human Behaviour raises a troubling question for public health: what if political polarization is no longer just shaping what people believe, but also how healthy they are?
Researchers Elizabeth Elder and Neil A. O’Brian examined individual-level medical data and death records from the National Longitudinal Study of Adolescent to Adult Health, a long-running study that has followed a nationally representative group of Americans since adolescence. Unlike many health datasets, this one includes both medical measures and political ideology, allowing the researchers to compare health outcomes across ideological groups over time.
The study found that conservatives and liberals in this cohort had similar health profiles in the late 2000s. But by 2016–2018, the most conservative respondents had worse health markers than the most liberal respondents. These markers included body mass index, cholesterol, blood glucose, blood pressure, and inflammation.
The divide became even more concerning in the early 2020s. Between 2020 and 2022, conservative respondents were more likely to die than liberal respondents, especially from internal causes such as heart disease, cancer, stroke, and diabetes. The authors note that COVID-19 contributed to the broader context, but the pattern was not limited to COVID-19 deaths.
So what might explain the widening gap?
Part of the answer appears to involve demographic and economic changes. The researchers found that shifts in education, income, health insurance, lifestyle factors, and geography explained some of the growing health divide. But those factors did not explain all of it.
The study points to another possible mechanism: trust in medicine.
In a separate survey of more than 21,000 adults, the authors found that right-leaning Americans, especially Republicans and Trump voters, were less likely to report trusting their primary care doctor, following medical advice, or believing that medications for chronic conditions are safe and effective. This pattern extended beyond COVID-19, encompassing routine care and chronic disease management.
The researchers are careful not to claim that ideology directly causes worse health. The study is descriptive, and more work is needed to understand cause and effect. Still, the findings suggest that political beliefs may now function as a social determinant of health. That means politics may shape not only policy environments, but also whether people seek care, trust clinicians, and follow treatment recommendations.
For public health, the implications are serious. A message that works in one community may fail in another if it is filtered through mistrust. Traditional public health communication may be less effective when medical guidance is seen as politically coded.
Public health agencies, clinicians, and community partners may need to invest more deeply in trusted messengers, local relationships, and communication strategies that respect people’s concerns without reinforcing misinformation. The goal should be simple: make prevention and care feel credible, accessible, and relevant across political divides.
Health polarization is not inevitable. But ignoring it may allow preventable illness and death to grow even further apart.
