Insomnia may be linked to a higher risk of developing certain cancers in people under the age of 50, according to new research.
A large-scale study involving nearly 18.9 million participants found that individuals with poor sleep patterns were more likely to be diagnosed with early-onset breast, bowel, womb and ovarian cancers.
In a broader public health context, researchers have increasingly been examining how lifestyle factors such as sleep, diet and stress may contribute to rising cancer rates among younger adults.
Health experts say cancer diagnoses in people aged 20 to 40 have increased by around 24 per cent since 1995, prompting ongoing investigations into possible causes.
The study, conducted by Jefferson Health in New Jersey and the Anderson Cancer Centre in New Orleans, analysed data from adults aged 18 to 50 between 2021 and 2025.
Researchers found that women diagnosed with insomnia were three times more likely to develop breast cancer within five years compared to those without sleep disorders.
The risk of womb cancer was found to be double, while ovarian cancer risk was around 60 per cent higher among those with insomnia.
For both men and women, early-onset bowel cancer risk was also significantly higher, at approximately 85 per cent.
Presenting the findings at the American Society of Clinical Oncology conference in Chicago, researchers said sleep disruption may represent a potentially modifiable risk factor that warrants further study.
However, the study did not find any significant link between insomnia and cancers of the throat, stomach, pancreas, prostate or testicles.
Medical professionals note that sleep plays a key role in immune system regulation, and prolonged sleep deprivation may contribute to poorer overall health outcomes.
Experts also caution that lifestyle factors associated with insomnia, such as reduced physical activity, higher alcohol intake and poor diet, may also influence cancer risk.
The NHS recommends adults get between seven and nine hours of sleep per night and maintain consistent sleep routines to support overall health.
