Tossing and turning towards trouble: How insufficient sleep fuels cancer risk


    18th October 2023 – (Hong Kong) Sleepless nights are all too familiar for the average overworked, overstressed Singaporean. A recent ResMed survey found 8 in 10 residents report disrupted sleep, with most blaming untreated sleep apnea. This epidemic of sleep deprivation is more than just an annoyance – it may seriously elevate Singaporeans’ cancer risk.

    Local sleep studies reveal a majority get under the recommended 7 hours nightly. YouGov found 73% sleep less than 7 hours, a sharp 44% rise since 2018. This forebodes ill health, with strong links emerging between insufficient sleep and cancers of the breast, colon, ovaries, and prostate.

    The mechanics are complex, but essentially poor sleep desynchronizes the body’s internal clock governing vital functions. This stokes inflammation and impedes cancer-fighting immune defences, creating an environment ripe for tumours to develop. Those sleeping less than 6 hours face a stark 41% higher cancer risk versus 6-8 hours, and napping over an hour daily further slashes risk by 60%.

    Light exposure at night while working also suppresses the sleep hormone melatonin, promoting cancer cell growth. Doctors have observed higher instances of breast and prostate cancers among shift workers. While evidence remains inconclusive for mobile devices, their blue light emissions may be problematic.

    Sleep experts like Dr. Wong Sheau Hwa in Singapore have seen various sleep-deprived cancer patients. Beyond breast and prostate tumours, they also suffered cancers of the colon, lung, and pancreas. Wong notes precise prevalence is unclear since cancers like colon cancer cause fatigue, complicating directionality. Overall though, poor sleep promotes genetic mutations enabling cancer.

    The bad news continues regarding weekend lie-ins. Our circadian cycles operate on 24-hour rhythms, so fluctuating sleep and wake times remain disruptive. Making up lost sleep does not compensate for accumulative harm. For shift workers, options are limited beyond proper screening and reducing light exposure.

    Wong suggests well-balanced diets and regular exercise as additional pillars, alongside sleep, for reducing cancer risk. Physical activity benefits the immune system and regulates hormones involved in cancer growth. No singular “superfood” protects against cancer, but overall healthy eating does matter.

    Cancer and sleep intersect in other complex ways too. Treatment side effects like pain, nausea, and emotional turmoil often persistently disturb sleep. Anxiety over diagnosis and prognosis also breed insomnia. Consequently, quality sleep remains elusive for many patients and survivors.

    A Johns Hopkins study found nearly 25% of childhood cancer survivors reported sleep initiation and maintenance problems. This impeded school and workplace performance, highlighting sleep’s broad impact on functioning. Younger survivors especially need adequate rest to thrive developmentally.

    Overall, long-term sleep disruption potentially heightens later susceptibility to chronic diseases by exhausting the body’s restorative capacities prematurely. This includes cancer risks, which accumulate from oxidative damage over time. Actively addressing sleep issues via relaxation techniques, therapy, and lifestyle changes is vital for patients.

    Beyond disease prevention, quality sleep also affects cancer progression and prognosis. According to Stanford research, breast cancer patients who slept fewer than 6 hours nightly were more likely to have recurrent tumours versus longer sleepers. Insufficient sleep impairs the immune system’s ability to keep malignancy in check.

    Conversely, excessive sleep brings risks too, like metabolic disorders that create a carcinogenic environment. Moderately disrupted sleep from apnea and insomnia may share common pathways with cancer development. However, causality remains unproven, and undiagnosed cancers often cause fatigue that lengthens sleep. Disentangling the relationship requires more research through rigorous longitudinal studies.

    Overall, most evidence indicates chronic sleep deprivation enables higher cancer risk while restful sleep aids recovery. Investing in healthy slumber provides dividends across all aspects of life. For Singapore’s sleep-starved workforce, fighting cancer begins with winning the battle against exhaustion. Treating disorders like sleep apnea improves sleep quality and longevity.

    Our doctrines of productivity and success require revaluation if progress destroys health. Knowledge of sleep’s ties with killer diseases like cancer should spur individual and collective action towards rest, before time runs out. Along with diet and exercise, adequate sleep forms a foundation for living life to the fullest.