Cutting corners on sleep has been normalised under the pretext of work or getting some additional me-time by binge-watching at night. It is often the first thing to be compromised when life gets busy, gradually turning late nights into a regular habit.
Can regular poor sleep be life-threatening and increase cancer risk? Dr Ashish B Agrawal, associate director and head (Unit II) – medical oncology, haematology and BMT, Sarvodaya Hospital, Sector-8, Faridabad, revealed that chronic sleep disruption deserves greater attention. But there is no evidence of a direct cause-and-effect relationship between poor sleep and cancer.
“Current human evidence is not strong enough to establish a simple cause-and-effect relationship. What research does show is that persistent sleep and circadian disruption can affect biological systems involved in cancer development,” he said.
This means poor sleep may create conditions that are favourable for cancer development. Despite there being no direct cause-and-effect relationship, chronic sleep deprivation may affect biological processes associated with cancer risk.
He cautioned against treating sleep as downtime and stressed that it should be prioritised. But before you fret over pulling an all-nighter to meet a deadline, the oncologist assured that one or two nights of poor sleep are not expected to influence your likelihood of developing cancer. So, when does poor sleep become a concern?
How is poor sleep harmful?
Poor sleep becomes a problem when it becomes a persistent pattern rather than an occasional occurrence. Irregular sleep schedules and night-time work can disturb your body’s natural internal clock.
Dr Agrawal described how the circadian rhythm is closely connected to other physiological systems: “The real issue is the case of chronic sleep deprivation along with inconsistent sleep mode and night-time working patterns. Our body is programmed in accordance with circadian rhythm, which is a biological clock that regulates a variety of relevant functions including sleeping, hormonal release, metabolic processes, defence mechanisms of the body and recovery.”
So when you go without good-quality sleep for a prolonged period, it can interfere with your hormonal balance, metabolism, immune defences, and the body’s ability to recover. When these systems are disrupted together, they may create conditions that are more favourable for disease development.
Additionally, the oncologist highlighted the role of melatonin, the hormone associated with the sleep-wake cycle. He said, “Melatonin also interacts with pathways involved in oxidative stress, DNA damage, and cell proliferation. Repeated exposure to light at night can suppress normal melatonin signalling.” Moreover, Dr Agarwal warned that chronic sleep loss can cause systemic inflammation, which may affect immune-cell function and metabolic regulation.
Describing how oxidative stress is responsible, he said, “The excessive oxidative stress can harm proteins and DNA, but DNA damage will not automatically lead to cancer as cells have ways to repair it. However, repeated DNA damage together with failure to regulate the process may generate conditions that would eventually result in carcinogenesis, which is the transformation of normal into malignant cells.”
Can better sleep prevent cancer?
Dr Agarwal clarified that good sleep, sure, does support preventive health, but it should not be treated as a guaranteed way to prevent cancer. It is one part of a broader healthy lifestyle.
“Although sleep should be included in preventive health practices, it cannot be considered a method of treating cancer or keeping it at bay. Adults are usually recommended to get a minimum of seven hours of quality sleep on a regular basis,” he said.
So getting enough sleep supports the biological processes that protect your overall health, but it cannot guarantee that you will remain cancer-free.
Dr Agarwal noted, “Cancer prevention is about the principles we already know well, including refraining from smoking, having a healthy weight, drinking less alcohol, exercising, getting screened in accordance with the prescribed schedule, and getting inoculated against possible infections. Good sleep is part of this list of recommendations.”
Note to readers: This article is for informational purposes only and not a substitute for professional medical advice.
