FRIDAY, Sept. 25, 2026 (HealthDay News) — Loneliness and social isolation can cost a person up to six years of healthy life, a new study says.

Physical and mental health suffer when people feel lonely and become isolated, even if they largely stick to healthy habits, researchers reported recently in the journal Nature Communications.

The two conditions are different. Social isolation refers to having few relationships or limited contact with others, while loneliness is a distressing feeling caused by a lack of meaningful connection, according to the National Council on Aging.

In other words, people can be socially isolated but still not feel lonely if they are getting what they need from whatever connections they do have. 

Roughly half of all U.S. adults are lonely, and nearly as many feel socially isolated, researchers said in background notes. These numbers paint a grim picture for America’s future health. 

“Overall, the study found that social isolation and loneliness can have a significant impact on disease-free life expectancy,” senior researcher Dr. Lu Qi said. He is a professor in the School of Public Health and Tropical Medicine at Tulane University in New Orleans. 

“This includes both physical and mental disease,” Qi added in a news release.

Researchers tracked more than 277,000 people ages 40 to 69 who entered the study free of seven major health problems — diabetes, heart disease, lung disease, dementia, cancer, depression and anxiety. The people were participants in the UK Biobank, a long-term health study in the United Kingdom.

The team measured how loneliness and social isolation affected the number of disease-free years people could expect to live, starting at age 50 as a reference point.

Women with both loneliness and social isolation lived an average of 2.4 fewer years free of physical health problems, while men lived 1.7 fewer disease-free years, the results showed.

Mental health suffered even worse. Women lived about 3.7 fewer years free from mental disorders, and men 5.8 fewer years.

“This comes down to the gender differences between men and women,” Qi said. “Our research found men are more susceptible to being affected by loneliness. We also know that women tend to live longer than men. There are gender advantages with certain diseases.”

Notably, a healthier lifestyle — diet, exercise, sleep and not smoking — narrowed the loss of disease-free years linked to social isolation, but did not significantly reduce the health risks of loneliness.

“The findings weren’t surprising to me,” Qi concluded. “Previous studies found that social isolation and loneliness are related to mortality, especially premature mortality, and this study provides additional evidence.”

More information

The National Council on Aging has more about loneliness and social isolation.

SOURCE: Tulane University, news release, Sept. 22, 2026