A new study has found that people with limited social interaction may face a higher risk of developing cancer, with women appearing particularly vulnerable. The research adds to growing evidence that social isolation can have serious effects on long-term health.
Previous studies have already linked loneliness to conditions such as depression, heart disease and dementia. With around a quarter of adults in the UK reporting feelings of loneliness and more than 4.2 million people aged over 65 living alone, experts say the health implications of social disconnection are becoming an increasing concern.
Large Study Tracks Over 350,000 Participants
Researchers in China analysed health data from 354,537 participants in the UK Biobank, aged between 38 and 73. At the beginning of the study, none of the participants had cancer. They were followed for nearly 12 years to examine the relationship between social isolation, loneliness and cancer risk.
To measure social isolation, participants completed questionnaires about their living arrangements, how often they met friends or family, and whether they took part in social activities at least once a week. Points were assigned for living alone, seeing family or friends less than once a month, and not participating in regular social activities.
Those who scored at least two points were classified as socially isolated, accounting for roughly six per cent of the participants. Meanwhile, 15,942 individuals reported persistent feelings of loneliness and difficulty confiding in others.
Isolation Linked To Increased Cancer Cases
During the follow-up period, 38,103 participants were diagnosed with cancer. After adjusting for other factors such as smoking, mental health and pre-existing conditions, the researchers found that social isolation was associated with an 8 per cent higher risk of developing cancer.
Women who had little social contact appeared to face greater risks than men. The study found that socially isolated women were more likely to develop breast, lung, womb, ovarian and stomach cancers.
Notably, women who rarely participated in social activities were found to have an 84 per cent higher risk of stomach cancer compared with those who maintained regular social connections. Both men and women who were socially isolated also showed an increased risk of bladder cancer.
Loneliness Alone Not A Key Risk Factor
Interestingly, the researchers noted that loneliness by itself did not significantly increase cancer risk across the overall population. In some groups, including individuals aged 49 and younger or those who were employed, loneliness was associated with a slightly reduced cancer risk.
Study lead author Dr Jiahao Cheng said the findings suggest social isolation and loneliness should not be treated as identical issues.
“Social isolation, as an objective state of reduced social contact, can influence health behaviours and biological processes such as stress responses, inflammation and cellular changes, which may contribute to cancer development,” he explained.
Addressing Social Isolation Through Public Health
The researchers suggested that wider factors such as income, lifestyle habits and inflammation may help explain why socially isolated individuals face greater cancer risks. They emphasised that health policies addressing socio-economic challenges and unhealthy lifestyles could help reduce these risks.
Experts say the findings highlight the importance of social connections as part of overall health and wellbeing. As societies become more digitally connected but physically distant, strengthening social networks may play a role in preventing a range of chronic illnesses.
The study was published in the journal Communications Medicine.
