Many Americans feel alone; a 2023 report found that about half of adults in the United States are lonely. Nearly as many also lack regular social contact. Experts say these problems are as harmful as other well-known health risks. Still, the public rarely treats them as urgent.
One big question has been left unanswered. How many healthy years do people lose because of these conditions? Until recently, scientists had no clear number. A new study from Tulane University has now offered one. The work came from the Celia Scott Weatherhead School of Public Health and Tropical Medicine. It was published in the journal Nature Communications. It is the first study of its kind.
The findings are serious. People who are both lonely and socially isolated lose close to six years of life without mental disorders such as depression and anxiety. They also lose some years free of physical illness, though the loss is smaller. Lead author Lu Qi holds a chair at the school and is a professor there. He said the results show a real effect on years lived without disease, both physical and mental.
The two terms are not the same. Experts define them differently. Social isolation can be counted. It refers to how many social ties a person has and how often they see others. Loneliness is a feeling. It describes how unhappy someone is with their relationships. A person can have a busy social life and still feel lonely. Another person might feel fine even if they spend a lot of time alone.
Qi was not surprised by the results. Earlier research had already linked both conditions to early death. This study adds more proof to that link.
The team studied 277,489 adults aged 40 to 69. At the start, none of them had any of the seven major long-term conditions. These were diabetes, heart disease, lung disease, dementia, cancer, depression and anxiety. The researchers followed the group over time. They then estimated how many disease-free years a person could expect after age 50, depending on their level of loneliness and isolation.
The results differed for women and men. Take people who were both lonely and isolated, and compare them with people who were neither. Women in the first group had 2.4 fewer years without physical disease. Men had 1.7 fewer years. The gap for mental health was larger. Women had about 3.7 more years with mental disorders. Men had about 5.8 fewer years.
Qi noted that loneliness seems to have a greater impact on men. He also pointed out that women generally live longer than men. In his view, the two sexes have different strengths and weaknesses when it comes to certain diseases. These differences help explain the pattern.
Lifestyle also played a role. Beneficial habits included a healthy diet, regular exercise, enough sleep and avoiding cigarettes. People who kept these habits lost fewer healthy years to social isolation. However, the same habits did not clearly reduce the extra risks tied to loneliness. This suggests that the two problems may need different kinds of help. Fixing one may not resolve the other.
This was an observational study. That means it shows a link, but it cannot prove that loneliness or isolation directly caused the lost years. The team plans to look at other groups of people next. They also want to test cause and effect through clinical trials.
The message is clear. Social connection is not just a lovely extra. It seems to matter for both the body and the mind. Doctors, families and communities may need to pay closer attention to people who feel alone or have few contacts. Even small steps, like calling a friend, can help.
