A lack of sleep could be quietly fuelling a rise in young people being diagnosed with cancer, experts have warned.
It has long been suggested that people who regularly struggle to sleep, known as insomniacs, are more likely to develop the disease than those who sleep well.
Sleep disorders are on the rise in the UK, with almost a fifth of adults not getting enough sleep.
The number of young people diagnosed with cancer has also surged by almost 80 per cent in the last three decades, with more than one million under 50s dying from the disease each year.
Experts are still searching for a reason why, with many suggesting there is unlikely to be one smoking gun.
However, experts at the annual meeting of the American Society of Clinical Oncology, in Chicago, believe poor sleep could be partly to blame.
The study found that people with sleep problems were more likely to develop early‑onset bowel, breast, ovarian and uterine cancer.
Dr Rowan Miller, a consultant oncologist at University College London, said poor sleep could be contributing to the mysterious rise in cancers with no obvious behavioural risk factors like smoking, drinking or obesity.
Insomniacs are up to three times more likely to develop breast cancer
‘It’s true that a lot of cancers are rising in young people – including ovarian cancer,’ Dr Miller said.
‘What isn’t clear is why certain cancers – which aren’t considered lifestyle cancers associated with obesity, smoking or a lack of exercise – are on the rise.
‘But, there’s clearly something in the way that we live our lives now that’s increasing the risk of lots of different cancers, and insomnia could be partly to be blame, affecting hormone levels which could increase the risk of cancer.’
The study, spearheaded by researchers at Jefferson Health New Jersey and the Ochsner MD Anderson Cancer Center, found that insomniacs were 57 per cent more likely to be diagnosed with ovarian cancer within five years of their diagnosis.
They were also more than three times as likely to develop breast cancer and about twice as likely to be diagnosed with bowel cancer in the same time period – both of which appear to be affected by smoking and obesity.
Commenting on the research, which involved more than 413,000 people with insomnia and over 18 million people without sleep issues, experts labelled the findings ‘interesting,’ but said further research is needed to better understand the link between sleep and cancer.
Dr Miller added: ‘I think it’s likely multifactorial but it’s certainly clear that we are seeing more cancers in younger people.
‘A lack of awareness of symptoms, smoking, drinking and living a sedentary lifestyle are all going to increase the risk of disease.’
Dr David Garley, a GP and director of the Better Sleep Clinic in Bristol, England, added that the relationship can also work in reverse, with underlying cancers that have not yet been picked up impacting sleep quality.
He also said that when people are sleep deprived, other health conscious behaviours like exercise, eating well and socialising with friends are likely to fall by the wayside, increasing the risk of the disease.
Around one in three adults in the UK – 16 million people – are thought to suffer from insomnia.
There are around 7,500 cases of ovarian cancer cases every year in the UK.
