People who have little social contact, especially women, are at an increased risk of developing cancer, concerning new research has found.
Mounting research has suggested that loneliness can be extremely detrimental to our health, increasing the risk of depression, heart disease and even dementia.
Official statistics show around a quarter of UK adults report feelings of loneliness, while 4.2million people aged over 65 live alone.
Now Chinese researchers, who analysed data from over 35,000 UK adults, have found that people who are socially isolated are more likely to develop cancer – but loneliness alone wasn’t enough to raise the risk.
Writing in the journal Communications Media, they said: ‘We propose that factors such as income, lifestyle habits, and inflammation might help explain this connection.
‘Addressing socio-economic challenges, unhealthy lifestyles and poor mental well-being, particularly for women, through health policies could help reduce cancer risk in isolated populations.’
The study analysed data from 354,537 UK Biobank participants, aged 38-73-years old.
At the start of the study, all participants were cancer free.
Women who reported feelings of isolation were significantly more likely to develop cancer
In order to assess social isolation, participants completed a questionnaire about how many people they lived with, how often they saw family or friends, and which leisure activities they engaged in at least once a week.
One point was awarded for living alone, another for visiting family and friends less than once a month and one for no participation in social activities at least weekly.
Individuals who scored at least two points were defined as socially isolated, making up around 6 per cent of the cohort.
Those who said they often felt lonely and felt like they could very rarely confide in someone were considered lonely – with 15,942 participants falling into this category.
Participants were followed for just under 12-years, during which time 38,103 were diagnosed with cancer.
After adjusting for potentially confounding factors – including existing health conditions, smoking status and mental health – researchers concluded that social isolation is associated with an 8 per cent increased cancer risk.
Women who had little social contact were more likely to develop cancer than men – with isolation increasing the risk of breast, lung, womb, ovarian and stomach cancers in women specifically.
Notably, women who rarely engaged in social settings had an 84 per cent increased risk of stomach cancer, compared to those who were not socially isolated.
Both sexes who were socially isolated were at an increased risk of bladder cancer.
Although loneliness had no significant effect on the overall population, younger individuals, aged 49-years-old and younger, showed decreased cancer risk with loneliness, as did those with a job.
Dr Jiahao Cheng, study first author, said: ‘Our study shows that while social isolation and loneliness may be conceptually related, the play distinct and independent roles in cancer incidence.
‘Social isolation as an objective state of reduced social contact, directly influences health behaviours and biological processes, including stress, pro-inflammatory responses and altered cellular pathways, all of which contribute to cancer development.’
They concluded: ‘To reduce cancer risk, addressing social isolation and loneliness directly is crucial, as well as developing effective preventive strategies to mitigate the effects of potential mediating factors.’
Bladder cancer is one of the ten most common cancers in the UK, with around 18,000 new cases and 6,000 deaths every year. When caught early, it can often be treated successfully.
But symptoms often hide behind common urinary symptoms, such as abdominal pain, exhaustion and pain or burning when passing urine, meaning many cases go undiagnosed until it is far more dangerous.
Breast cancer is also thought to be on the rise with now one in seven women in the UK diagnosed with the disease in their lifetime, making it the most common cancer in the UK.
But researchers now say more than a quarter of the healthy years lost to breast cancer globally can be traced to seven modifiable risk factors: obesity, high blood sugar, smoking, second hand smoke, heavy alcohol use, low physical activity and high red meat intake.
