Research found an association between poor sleep and early-onset cancer (Image: Getty)
Poor sleep may be fuelling a worrying rise in cancers among under 50s, according to a study of almost 19 million people. Insomniacs were up to three times more likely to develop some forms of the disease compared to people who slept soundly. The research looked at a range of early-onset hormone-related and gastrointestinal cancers.
Bad sleepers had triple the risk of being diagnosed with breast cancer within five years of an insomnia diagnosis. They were almost twice as likely to develop uterine cancer, nearly twice as likely to be diagnosed with early-onset bowel cancer, and had a 57% higher risk of ovarian cancer.
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Researchers at Jefferson Health New Jersey and the Ochsner MD Anderson Cancer Center, both in the US, used data from more than 413,000 people aged 18-50 with diagnosed insomnia and 18.4 million people without sleep problems.
Presenting their results in two abstracts at the American Association for Clinical Oncology’s annual conference in Chicago, the team concluded that sleep disruption “may represent a clinically relevant, potentially modifiable risk factor” for some cancers.
The study comes amid mounting global concern about a rising tide of the disease among people under the age of 50.
Recent analysis by the Institute of Cancer Research in London and Imperial College London found that 11 cancers — including breast, bowel, liver, kidney, pancreatic and ovarian cancer — were becoming more common among younger adults.
Claire Coughlan, clinical lead at Bowel Cancer UK, said: “Bowel cancer is more common in the over 50s, but there is a growing body of evidence globally that bowel cancer is increasing in younger people, including within the UK.
“We don’t know exactly why this is yet, but researchers currently believe it may be due to genetics, and lifestyle factors.
“This study’s conclusion that insomnia may be a potential risk factor in early-onset colorectal cancer could go some way to helping us understand the reasons behind this increase. The findings of this study are worth exploring further.”
Around one in three adults, or 16 million people, suffer from insomnia in the UK. Dr David Garley, a GP and director of The Better Sleep Clinic, said there was strong evidence that insomnia drives health conditions such as diabetes, heart disease and poor mental health.
The case for cancer is “not clear cut”, he added, but one possibility is that people with insomnia are typically less healthy. Dr Garley said: “When sleep deprived it’s difficult to live a healthy life — there is more drinking, more obesity, less exercise, more smoking etc. — and these may be what causes any possible increased risk.”
Around 16 million Brits suffer from insomnia (Image: Getty)
Sleep also plays a vital role in restoring the immune system and infections can increase the risk of some cancers, Dr Garley said.
Another possibility is that people with insomnia are more likely to suffer from health anxiety, which may prompt them to visit the doctor sooner when they notice symptoms. Dr Garley stressed that the study showed a link rather than proof that insomnia causes cancer.
He added: “Insomnia is often very closely linked to anxiety. If you start to over-emphasise a possible risk of cancer when you’re not sleeping, then that really heaps on the pressure and makes it even worse.”
Simon Vincent, chief scientific officer at Breast Cancer Now, said: “With breast cancer cases on the rise in the UK and globally, we welcome research that aims to understand what’s driving this trend.
“While this new research is a starting point, we need more evidence to know if there’s an association between insomnia and breast cancer.”
Megan Winter, health information manager at Cancer Research UK, agreed that more research was needed. She said: “There are proven steps people can take to reduce their cancer risk if they are worried, which include not smoking, keeping a healthy weight, and staying safe in the sun.
“If anyone notices something that’s not right for them, they should talk to their doctor. It probably won’t be cancer, but if it is, spotting it at an early stage can make all the difference.”
