Loneliness and healthy years: what a large study found — and what it didn't

More than a decade ago, several hundred thousand middle-aged Britons answered a few simple questions. How often do you see friends or family? Do you live alone? How often do you feel lonely? At the time, the answers were just lines in a questionnaire for UK Biobank, a large health research project.

Now researchers at Tulane University in the United States have matched those answers with what happened to the same people over the following years. Their findings, published this year in Nature Communications, quickly travelled under headlines such as "loneliness steals six years of life". The figure is real. But to understand what it means, we first need to separate two words we tend to use as if they were the same.

Loneliness and isolation are not the same thing

The World Health Organization draws the line like this. Social isolation is the objective lack of sufficient social connections: living alone, rarely seeing others, taking part in no shared activity. Loneliness is the painful feeling that comes from a gap between the relationships a person wants and the ones they actually have.

The two do not always go together. You can live alone and not feel lonely. You can have a large family, a busy workplace and weekly get-togethers — and still feel deeply lonely.

The study measured the two separately. Isolation was assessed through facts: living alone, how often people saw friends or family, whether they joined any group activity. Loneliness was assessed through people's own feelings.

What the study found

The participants were 277,489 adults aged 40 to 69. At the start, none of them had any of seven major chronic conditions: diabetes, heart disease, lung disease, dementia, cancer, depression or anxiety. They were then followed for many years.

The authors estimated how many years after age 50 people live, on average, without these conditions, and compared groups. People who were both lonely and socially isolated at the start had fewer such years than people who were neither:

• years free of depression and anxiety — about 5.8 fewer for men and 3.7 fewer for women;
• years free of major physical disease — 1.7 fewer for men and 2.4 fewer for women.

So the "six years" refers specifically to mental health, to men, and to having both conditions at once. For physical health the gap is noticeably smaller, though still significant, according to the authors.

The most interesting part is in the detail

The researchers also checked whether a healthy lifestyle — diet, exercise, sleep, not smoking — changed the picture. The answer was different for the two conditions.

For social isolation, healthy habits narrowed the gap in healthy years. For loneliness, they did not: the authors found no statistically significant reduction.

This result should be read with care, but it points to something important. Isolation may be partly offset by what a person does on their own. Loneliness seems to work differently: it is not about steps or hours of sleep but about the quality of relationships. Lead author Lu Qi also noted that, in their data, men appeared more vulnerable to the effects of loneliness.

What this study does not prove

The key limitation is that this is an observational study. It shows an association, not that loneliness causes disease. The arrow could also point the other way: someone whose health is starting to decline may gradually withdraw from others. The authors say clinical trials should be the next step.

There are other caveats:

• loneliness and isolation were assessed at the start of the study, although a great deal can change over the following years;
• UK Biobank participants are volunteers who are, on average, healthier than the general population;
• the participants were middle-aged Britons, so the results cannot simply be transferred to other countries or age groups.

The honest summary, then: loneliness and isolation are associated with fewer years free of disease, and the link holds even in a very large sample. Whether it is causal remains an open question.

Who is lonely: an unexpected picture

We tend to think of loneliness as a problem of old age. Recent data tell a different story.

The WHO estimated in 2025 that loneliness affects about one in six people worldwide. Among people aged 13 to 29, 17–21% report it, with the highest rates among teenagers. In low-income countries loneliness is roughly twice as common as in high-income ones: about 24% against 11%.

In England, the government's Community and Engagement Survey 2025/26, with more than 175,000 responses, found that 7% of adults feel lonely often or always. The rate was highest among 16–24-year-olds (9%) and lowest among 65–74-year-olds (4%).

Across the EU, the first joint survey on loneliness, carried out in 2022 with more than 25,000 respondents, found that about 13% felt lonely most or all of the time. Ireland had the highest rate (over 20%), while the Netherlands, Czechia, Croatia and Austria were below 10%. Here, too, younger people reported loneliness more often than older generations.

One caveat: different surveys ask different questions, so their numbers cannot be compared directly. But they point in the same direction.

What society can do

If loneliness is not only a personal misfortune, the response cannot be only personal either. Some countries have recognised this at government level. The United Kingdom launched its first national loneliness strategy in 2018, and Japan appointed a minister for loneliness and isolation in 2021.

In its roadmap, the WHO stresses "social infrastructure": places where people can meet without a special reason, such as parks, libraries, cafés and clubs. It also calls for better measurement of social connection, so that policies can be tested against data rather than intuition.

At the same time, the British study's finding on lifestyle is a reminder of the limits of simple fixes. Isolation may be eased by getting out of the house more often; loneliness seems to require something else — not more contacts, but deeper ones.

What it means for readers

The most useful takeaway from this study is not fear of the "six years" figure, but a sharper question to ask yourself. Not "how many contacts do I have?" but "are there people around me I can really talk to?"

And a second one: loneliness is not a sign of weakness, nor a rare condition. Teenagers and retirees feel it, in cities and in villages, living alone or with family. Talking about it calmly is already part of the answer.

This article is not medical advice. If loneliness or low mood lasts a long time, it is worth speaking to a professional.

Questions for discussion

1. How do you tell loneliness and isolation apart in your own life — have you ever been surrounded by people and still felt lonely?
2. Why do you think young people today report loneliness more often than older generations?
3. Which places in your town or neighbourhood help people meet without a special reason — and which are missing?