# Loneliness (as health risk)

Loneliness, the subjective feeling of social disconnection, is now recognised as an independent risk factor for cardiovascular disease, dementia, and early mortality. Meta-analyses by Holt-Lunstad and colleagues found that strong social relationships were associated with ~50% greater odds of survival (2010, PLOS Medicine), and that social isolation, loneliness, and living alone independently raise all-cause mortality risk by roughly 26–32% (2015, Perspectives on Psychological Science) — an effect Holt-Lunstad has compared by analogy to the mortality risk of smoking up to 15 cigarettes a day, a framing later cited in the 2023 US Surgeon General's Advisory on the epidemic of loneliness and isolation. It dysregulates inflammation, sleep, and HPA-axis stress responses. In longevity science, addressing loneliness through community, purpose, and relationships is a primary, evidence-based intervention.

## Sources

- Holt-Lunstad J, Smith TB, Baker M, Harris T, Stephenson D. (2015). Loneliness and Social Isolation as Risk Factors for Mortality: A Meta-Analytic Review. Perspectives on Psychological Science. https://doi.org/10.1177/1745691614568352
- Holt-Lunstad J, Smith TB, Layton JB. (2010). Social Relationships and Mortality Risk: A Meta-analytic Review. PLOS Medicine. https://doi.org/10.1371/journal.pmed.1000316

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_Canonical: https://longevity-germany.com/en/glossary/loneliness-health-risk · Part of Longevity Cities · Updated 2026-05-02_