The Study
Social isolation, C-reactive protein, and coronary heart disease mortality among community-dwelling adults
This study found that people who didn't have many friends or social connections were more likely to have high inflammation and die from heart disease later on. But it didn't prove that being lonely caused the heart disease—it just showed that these two things often happened together.
Analysis score
Maximum 72 for a cohort study.
Where the score came from
People with very few friends or social ties were much more likely to die of heart disease 15 years later—even if they weren’t overweight, didn’t smoke, and had normal blood pressure.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 558 / 100
Quality score
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes—this means being extremely lonely is as risky for your heart as smoking or high cholesterol, even if you look healthy on standard tests.
- 2People with the least social ties had 2.69x higher odds of high inflammation (CRP >3.0 mg/L) and 2.66x higher odds of dying from heart disease than those with the most social ties.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Social science & medicine (1982)
Year
2011
Authors
K. Heffner, M. Waring, M. Roberts, C. Eaton, R. Gramling
Related Content
Claims (6)
Prolonged social isolation is associated with sustained activation of inflammatory pathways that contribute to gradual deterioration of heart tissue and function.
Middle-aged adults with fewer social connections are more likely to have higher levels of a blood marker called C-reactive protein, which indicates systemic inflammation, even when accounting for age, body weight, and income.
Over a 15-year period, adults who had fewer social connections were 2.66 times more likely to die from coronary heart disease than those with more social connections, even when accounting for age, sex, and traditional cardiovascular risk factors.
People with higher levels of C-reactive protein in their blood have a 2.22 times greater chance of dying from coronary heart disease over 15 years, even after accounting for social isolation. This suggests that C-reactive protein predicts mortality risk on its own, but it does not explain why social isolation is linked to heart disease death.
People who experience social isolation have the same levels of diabetes, body weight, physical activity, and calculated heart disease risk as those who are socially connected, suggesting that social isolation affects heart disease death rates through different biological mechanisms than these known risk factors.
People who are severely socially isolated have a higher risk of dying from coronary heart disease compared to those with moderate or high levels of social connection; however, there is no meaningful difference in risk between those with moderate and high levels of social connection.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.