Studies Link Insomnia to Cancer Risk in Under-50s

The results arrive amid a global surge in early-onset cancer. Cases worldwide rose from 1.82 million in 1990 to 3.26 million in 2019 — an increase of nearly 80% — while cancer deaths among people in their 30s and 40s climbed 27%. In the UK, bowel cancer has jumped 22% among adults aged 25 to 49. Women with insomnia faced triple the breast cancer risk, almost double the uterine cancer risk, and a 57% higher ovarian cancer risk. Both sexes were twice as likely to develop bowel cancer. However, no similar link was found between insomnia and hormonal cancers in men, such as prostate or testicular disease.

Independent experts welcomed the studies but cautioned that they show association, not proof of cause. Poor sleepers often drink more, exercise less, and gain weight — habits that themselves raise cancer risk. Cancer Research UK urged longer-term work before any change in clinical advice. For now, experts say, people can lower cancer risk by not smoking, keeping a healthy weight, and protecting their skin from the sun.