Feeling lonely isn't just emotionally painful — it could cost you years of good health. A first-of-its-kind study from Tulane University, published in Nature Communications, found that loneliness and social isolation are associated with a significant loss of disease-free life expectancy, with the sharpest toll falling on mental health.

The study tracked over 277,000 adults aged 40–69, none of whom had seven major chronic conditions at the outset. Using age 50 as a baseline, researchers calculated how many healthy years were lost among those experiencing loneliness, social isolation, or both — compared to those experiencing neither. Notably, healthier lifestyle habits (diet, exercise, sleep, not smoking) reduced health risks tied to social isolation — but had little effect on the risks tied to loneliness, suggesting the two require distinct interventions.

By the Numbers:

• Men experiencing both loneliness and social isolation lost ~5.8 years free from depression and anxiety
• Women experiencing both lost ~3.7 years free from mental disorders
• Women lost 2.4 fewer years free from physical disease; men lost 1.7 fewer years
• About half of U.S. adults report experiencing loneliness

Why it matters: With roughly half of U.S. adults experiencing loneliness, this research underscores that social disconnection is a serious public health issue — one that may demand targeted mental health strategies beyond lifestyle advice alone.