Study: Social connection and mortality risk in older adults

When we talk about healthy aging and longevity, the conversation often centers on diet, physical activity, and biological mechanisms. In recent years, however, research has increasingly pointed to social factors as playing a far more significant role in health than previously assumed.

A recent systematic review and meta-analysis published in Aging Clinical and Experimental Research brings together evidence from a wide range of studies examining the relationship between social connection and mortality in older adults.

Read the blog to learn how, according to this study, living alone, loneliness, and social isolation may influence longevity and long-term health.

Study overview

This article is based on a large systematic review and meta-analysis published in Aging Clinical and Experimental Research in 2024. The study brings together evidence from 86 prospective observational studies examining how different forms of social connection relate to mortality risk in older adults.

Rather than focusing on a single social factor, the researchers set out to examine three related but distinct dimensions of social life: living alone, loneliness, and social isolation.

These factors are often grouped together in research and public discussion, yet the study highlights that they represent different aspects of social experience and may influence health and longevity in different ways.

The included studies followed older adults over time and assessed all-cause mortality as well as cause-specific mortality, including cardiovascular-related deaths. By pooling data across diverse populations, countries, and measurement approaches, the meta-analysis aimed to clarify how each social factor independently relates to longevity in later life.

To understand the findings of the study, it is important to distinguish clearly between these three concepts.

Living alone

Living alone refers to a person’s household situation and is a structural, demographic measure. It describes whether an individual resides alone or with others, without providing information about social engagement or emotional well-being.

The study emphasises that living alone should not automatically be interpreted as social disconnection. Many older adults who live alone remain socially active and well connected, while others who live with others may still experience limited social support.

Loneliness

Loneliness reflects a subjective experience of social disconnection. It is defined by how individuals perceive the adequacy and quality of their social relationships, rather than the number of contacts they have.

Within the context of the study, loneliness is understood as an emotional response that can occur regardless of living arrangements or social network size. This distinction helps explain why loneliness may be present even in socially active individuals.

Social isolation

Social isolation is an objective measure of social contact and participation. It typically captures aspects such as the size of social networks, frequency of interactions, and involvement in social activities.

Unlike loneliness, social isolation does not account for how individuals feel about their social situation. The study treats social isolation as a distinct construct, recognizing that limited social contact does not always lead to perceived loneliness, but may still have implications for health outcomes.

Why the distinction between these concepts matters

The study emphasizes that although these three social factors often overlap, they represent different aspects of social well-being. This distinction is important when examining their relationship with health and mortality. Without clearly differentiating between them, important nuances in how social factors influence aging and disease risk may be overlooked.

What does the research show about mortality?

Against this background, the study looks at how living alone, loneliness, and social isolation are reflected in outcomes later in life. According to the study, these factors do not carry the same implications for health.

Social isolation and mortality

Social isolation shows the strongest and most consistent association with increased mortality. The study finds that older adults with limited social contact and low participation in social activities have a markedly higher risk of both all-cause mortality and cardiovascular-related mortality compared with those who are more socially engaged.

This association is observed across different populations and measurement methods, suggesting that social isolation itself may act as an independent risk factor for earlier death in older age.

Loneliness and mortality

Loneliness is also associated with higher mortality risk, although the relationship is generally weaker than for social isolation. The study shows that older adults who report feeling lonely have a higher risk of all-cause mortality, and in some analyses, a higher risk of cardiovascular-related mortality.

The strength of this association varies more across analyses. According to the authors, this variation may reflect differences in how loneliness is measured and how it is experienced in different contexts. Overall, the findings suggest that perceived loneliness plays a role in survival in later life.

Living alone and mortality

Living alone is likewise associated with increased mortality risk, but the relationship is more moderate compared with both social isolation and loneliness. The study shows that living alone, on its own, is not a strong or consistent indicator of higher mortality.

The authors highlight that living arrangements do not necessarily reflect a person’s level of social connection. Many older adults who live alone remain socially active, while others who live with others may still experience isolation or loneliness.

Consistency and variation across studies

An important finding of the study is that the associations between social factors and mortality are observed across different countries, cultures, and measurement approaches. This strengthens the evidence that social connection is linked to survival in older adults across a wide range of settings.

At the same time, the authors note considerable variation between studies. Differences relate to how social factors are measured, how long participants are followed, and which health-related factors are adjusted for. Despite this variation, the overall direction of the findings remains consistent.

What does the study tell us?

The study provides a more nuanced view of how social relationships affect health later in life. By clearly distinguishing between loneliness, social isolation, and living alone, the research shows that these factors do not carry the same implications for mortality. According to the study, social isolation stands out as the most consistent risk factor, while loneliness and living alone play a more variable role.

At the same time, the researchers highlight that there is still a need for deeper insight into how these social factors interact over time. A better understanding of the interplay between different forms of social connection may be important for future efforts focused on supporting healthy aging.

How can this be approached in everyday life?

The study does not point to specific solutions, but its findings underline that social relationships matter for health in older age. In practice, this does not necessarily mean having many social contacts, but rather being mindful of both the presence and the quality of social connections in everyday life.

Small actions can make a difference. This might include regular contact with family or friends, taking part in communities that feel meaningful, or establishing simple routines that create opportunities for social interaction. At the same time, it is important to remember that living alone is not a problem in itself — many people thrive in their own company, as long as they feel connected to others.

For some, it may also be helpful to pay attention to signs of loneliness or social withdrawal, both in oneself and in those around us. Reaching out, checking in, or offering companionship can be small but meaningful gestures.

As the study shows, social relationships are not the same for everyone. Rather than one universal solution, what matters most is an ongoing awareness of how social connections fit into one’s life and overall well-being over time.