Our knowledge that social factors can influence health is abundant and has shaped research and policy across medicine, public health and society for decades. In this special issue, Nature Aging features a collection of reviews and opinion articles that explore how social factors influence healthy aging across the life course and become biologically embedded.

There is a long and rich history of thinking and research on how societal factors can affect human health. Socioeconomic, cultural and environmental circumstances — including where one lives, occupation and income, and access to education, food and healthcare — can all influence disease and mortality risks, psychological well-being, and physical and cognitive functions.

A well-known epidemiological example of how health is shaped by social factors came from the Whitehall study. A 1978 research paper on more than 17,000 middle-aged British civil servants showed that health followed a sociohierarchical gradient, such that lower employment grades were associated with poorer health and premature morbidity as compared with higher positions1.

These various societal factors are commonly referred to as the social determinants of health2,3. They can promote, protect or harm health, as early as conception, and tend to accumulate throughout life. Theoretically modifiable through policy or behavioral changes, these social and environmental factors present opportunities to improve public health and address health inequities within and across nations4,5.

As populations around the globe are aging, but often not in good health, understanding what and how social factors shape healthy aging is becoming increasingly important. In this special issue, Nature Aging presents a collection of reviews and opinion articles that explore the social determinants of healthy aging.

A Correspondence by HelpAge International emphasizes how humanitarian crises disrupt the social, economic and environmental conditions that support healthy aging, and proposes recommendations on how government and nongovernmental organization efforts should be adapted during such crises. In a Comment, Beard and Aiello argue for the need to track health trajectories continuously across the life course to understand how socioeconomic disadvantages become biologically embedded. Turning to productive aging, Gonzales and colleagues consider, in another Comment, how employment, volunteering and caregiving can support health and social cohesion for older adults, and call for interventions that make such engagement a choice rather than an obligation.

An interesting area of aging research aims to understand how the sum of all exposures across the life course, the so-called exposome, shapes health in aging. In a Perspective, Ibáñez and colleagues discuss how the exposome influences brain health as we age, and emphasize a global, integrative view of the multiple dimensions that influence dementia risk across income and geographical settings. The Gateway Exposome Coordinating Center (GECC), a consortium of epidemiologists, social scientists and health economists, offers a Consensus Statement that calls for greater interdisciplinary collaboration, closer attention to the timing and context of exposures, mechanistically informed measures, and better use of emerging data sources in exposome research on healthy aging. Together, their recommendations aim to connect complex environmental and social influences with actionable targets for intervention and policy.

Neighborhoods, communities and the built environment are all key for healthy aging. In a Review, Winterton and colleagues examine how policy, socioeconomic conditions, infrastructure, environmental changes and community resources interact in rural settings. They discuss how rural residence is not inherently associated with poor health and call for place-based approaches that recognize both the diversity and the capacities of older people and their communities. In another Review on the topic, Ji and colleagues introduce environmental health resilience as a framework for understanding how green space, age-friendly urban design, climate-resilient infrastructure and social connectivity can counter the effect of adverse exposures on disease risk and functional decline. They also propose that building such resilience is a complementary strategy to reducing exposure to promote healthy aging for all. Staying with the theme of social connections, Steptoe and Fancourt review the evidence that links social isolation with morbidity, mortality and biological aging. They highlight community leisure engagement, including participation in cultural, recreational, civic and nature-based activities, as a potentially modifiable component of social connections, and consider how targeted programs could mobilize community assets to support healthy aging.

Highlighting the need to move from association towards causation, Avendano and colleagues explore, in a Perspective, how experimental and quasi-experimental evaluations of social policies can help to understand whether changes in education, income, work or housing alter biological and functional trajectories of aging. Using education and cognitive aging as an example, they discuss how policy effects depend on the specific exposure targeted, the populations affected, and the life-course stage at which an intervention occurs. On the same theme of establishing causality, Bartolomucci and colleagues contribute a Perspective that considers how animal models can be used to identify causal mechanisms that link social adversity and aging. Bringing together evidence on early-life adversity, social connectivity and social status, they introduce the concept of experimental social geroscience that connects these social hallmarks with molecular hallmarks of aging, providing a framework for identifying biological pathways and potential targets for intervention.

One common theme emerging from this collection of articles is the need for a life-course approach to studying healthy aging, as the social, economic and environmental influences accumulate, interact and become biologically embedded from the early stages of life. Some of these articles also bring social epidemiology and geroscience closer together by discussing biology (including biomarkers of aging, mechanisms and causality) in a social context. They point to a potentially growing interface between these disciplines, but also to a shared goal: extending healthspan through prevention.

Altogether, this collection points to exciting opportunities to explore causal pathways at scale, identify sensitive periods for interventions, and test actionable policy levers for healthier and more equitable aging. We hope that this series of articles will stimulate further research efforts in these directions.

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