Why Socializing Can Support Your Immune System, Per New Study

Do you consider yourself a people person, social butterfly or extrovert? Maybe you’re always looking for social events to fill your calendar—and if you can’t find an event, you’ll create one. You love spending time with family and friends, even if that means just having a cup of tea and good conversation. If so, your social habits could be improving your health—and possibly even adding years to your life.

Loneliness and social isolation are common in the U.S. About one in three adults feels lonely, and about one in four has a lack of emotional and social support. Social isolation and loneliness can have some negative impacts on health, including increasing the risk of heart disease and stroke, type 2 diabetes, depression and anxiety, suicidality and self-harm, dementia and dying earlier than one would have without being lonely or socially isolated.

It’s important to note that there is a difference between social isolation and loneliness. Social isolation is an objective measure based on certain criteria—whether someone lives alone, how frequently they have contact with other people and whether they participate in social activities. Loneliness is a subjective measure based on whether someone feels lonely. You can be surrounded by people, but still feel lonely if you don’t feel a true connection to them. 

While researchers know there is an association between social isolation and loneliness with poorer health, they have yet to figure out the underlying cause of why this happens. But researchers at the University of Cambridge in the UK and Fudan University in China may have discovered some of the causes. They published their findings in the January 2025 issue of Nature Human Behaviour. Let’s see what they found.

How Was This Study Conducted?

Data was pulled from the UK Biobank, a large-scale biomedical database that contains detailed information about people’s demographics, medical histories, lifestyles, bloodwork results and numerous other medical tests, like MRIs. Researchers used information from 42,062 participants with an average age of 54 and just over half of them being female. Participants were followed for an average of 14 years.

All participants contributed quality-controlled proteomic data from bloodwork and complete behavioral data that included social isolation and loneliness status. A proteome is a complete set of proteins. Proteins are in every cell of our bodies and differ depending on the type of cell. They are essential for helping our bodies function properly. They also change and are influenced by many factors, including our behaviors and health status.

These researchers wanted to know if proteins offered a biological clue into why social isolation and loneliness influence health and disease status. 

What Did This Study Find?

After analyzing the proteomes and adjusting for certain confounding factors, like sex, age and socioeconomic status, the scientists discovered that 175 proteins were associated with social isolation and 26 were associated with loneliness. They also found an overlap of proteins, where about 85% of the proteins associated with loneliness were also associated with social isolation, creating a large interactive network of proteins related to immunity.

Researchers started connecting the dots with these findings and why those who are socially isolated and lonely tend to have high levels of inflammation. Many of the identified proteins are part of our immune response, which instigates the inflammatory response when our bodies are fighting off illness. Inflammation is also linked to chronic disease, including heart disease, stroke, cancer, type 2 diabetes and arthritis. 

The study authors were also able to isolate specific proteins and their effect on the body. For example, one of these proteins is called ADM. This protein helps regulate the body’s response to stress and stress hormones. ADM also regulates oxytocin, a hormone that encourages feelings of love and attachment. They found higher levels of ADM in people who were lonely, suggesting that their immune system was battling infection—or what it perceived as infection—due to loneliness. 

There was also an association between higher levels of ADM and a smaller insula, a part of the brain that controls interoception—the ability to feel what’s going on inside your body. In addition, higher ADM was also linked to changes in the left caudate, a region of the brain involved in several functions, including movement, emotions, cognition and social processes. 

Researchers note that over half the proteins associated with social isolation and loneliness also demonstrated a significant link with heart disease, type 2 diabetes, stroke and death. For example, a one-unit increase in ADM level was associated with a 58% increased risk of death during the 14-year follow-up period. 

ADM wasn’t the only stand-out protein. Another, called ASGR1, was associated with higher cholesterol levels and risk of heart disease. 

How Does This Apply to Real Life?

While researchers have known that social isolation and loneliness increase the risk of disease, including heart disease and diabetes, they did not yet know the reasons behind the association. This is one of the first studies to examine the potential biological reasons linking the factors together. 

“The World Health Organization has found that one in four older people are socially isolated and 5% to 15% of adolescents feel lonely,” says Barbara Sahakian, Ph.D., DSc, one of the study authors and a professor of psychiatry at University of Cambridge. “It is important for your physical and mental health and wellbeing not to let yourself become disconnected with those around you and feel lonely.”

There are several ways you can help prevent loneliness and isolation, says Sahakian. “Volunteering for a charity is an excellent way to boost your social connections and make new friends,” she suggests. “It also activates the reward system in the brain, giving us enjoyment and pleasure from doing a good deed.”

Sahakian also recommends exercising as part of a team sport or through cycling or walking clubs, since this will boost your mood, thinking ability, physical health and wellbeing. “Face-to-face book clubs are also a great way to stimulate your imagination and creative thinking and engage in interesting discussions while socializing,” adds Sahakian. 

Going to church, participating in group cooking lessons or taking classes to learn a new hobby are a few more ideas. You can also play a role in helping others feel less isolated and lonely. Share a meal and conversation with a neighbor or offer to play cards with or shop for someone you know who can’t get out. That phone call you’ve been putting off? Make it happen. 

Of course, you can spend time with people but not feel connected with them, which may cultivate feelings of loneliness. To deepen your connection with others, it’s important that you’re authentic and genuine and allow certain levels of vulnerability over time as you feel more comfortable. Build trust and rapport with the people in your life. If you have difficulty doing so due to past trauma, consider seeking appropriate professional help to work through the trauma. There is hope and post-traumatic growth on the other side! 

The Bottom Line

This study suggests that certain proteins related to inflammation are present at higher levels in people who are lonely or socially isolated, predisposing them to a higher risk of disease. There are also changes in the brain related to these proteins. If you’re feeling lonely or are avoiding social opportunities, it’s important to take action. 

“Find a social activity that you think is fun and make it a goal to make some new friends,” says Sahakian. “Getting social support from others and giving friends social support in challenging times will lead to a happier and more fulfilling life.”