Cancer is a major cause of death and disease in the world’s population. In their lifetime, approximately 21% of men and 18% of women are expected to be diagnosed with cancer. As the population grows and ages, these numbers are only anticipated to get worse.
In order for cancer to develop, a person’s cells must proliferate abnormally and invade other tissues. Rather than being a single disease, cancer can be caused by a variety of diverse factors.
Many sleep researchers are now focusing on the link between sleep and cancer because of the growing understanding of the importance of sleep in general health.
Despite the fact that further research is required, specialists have discovered a complex link. Certain types of cancer may be linked to a person’s inability to get a good night’s sleep. It’s possible that they have an impact on how quickly cancer spreads and how well the treatment works.
As a side effect, cancer can also disrupt sleep. A lack of sleep due to cancer symptoms or the side effects of treatment can have a negative impact on a patient’s quality of life. Cancer survivors, even those who have completed treatment, may experience sleep disturbances due to long-term physical and mental changes brought on by the disease.
It is possible to improve one’s health by learning about the complicated connections between cancer and sleep. The risk of cancer cannot be completely eliminated, however, having adequate sleep may be a preventative factor. Better sleep may help cancer patients feel better physically and emotionally, which in turn may improve their capacity to deal with the disease.
Can Sleep Affect Cancer?
The importance of sleep for human health has long been known. Evidence suggests that sleep may influence cancer in a variety of ways, given its influence on practically every system in the body.
The brain, immune system, synthesis and regulation of hormones, metabolism, and body weight may all be affected by sleep in ways that affect cancer risk. It is possible that sleep alters the environment in which cells operate and the signals that control how they grow.
The following sections provide an overview of current research on the potential effects of sleep on cancer risk, progression, and treatment, even though this is still a developing topic.
A consultation with a physician is recommended for anyone concerned about the quality of their sleep or their risk of cancer.
Sleep and Cancer Risk
Sleep length, quality, circadian rhythm, and sleep problems have all been linked to an increased risk of cancer. However, studies on this area are not always consistent or conclusive, which may be due to problems in collecting long-term data on sleep.
There has been a lot of debate over the years about how much sleep one gets and the likelihood of developing cancer. Sleep data collection methods, cancer types evaluated, and other factors that can affect cancer risk may all have a role in the outcomes.
The chance of death from any cause is higher for people who sleep less than six hours a night, and a recent study indicated that persons with short sleep have a higher cancer risk as well.
Short sleep duration has been linked to an increased risk of colon polyps that can develop into cancer in certain cancers. Some studies have linked lower sleep duration in older persons to an increased risk of stomach cancer, as well as cancers of the thyroid, bladder, head, and neck in older adults.
These investigations, on the other hand, are not conclusive. Short sleep has not been linked to an increased risk of many cancers, including lung cancer. People who sleep less than seven or eight hours a night are less likely to develop cancer, according to several studies.
Sleep deprivation has been linked in animal studies to increased cell “wear and tear,” which may lead to DNA damage that can lead to cancer. Sleep and cancer may be linked, even if human research has yet to reveal this conclusively.
In addition, sleep deprivation may raise the risk of cancer. Obesity, a well-documented risk factor for a wide variety of cancers, has been shown to be correlated with insufficient sleep. Sleep deprivation has been linked to an increased risk of cancer because of immune system disorders such as chronic inflammation.
Sleeping more than nine hours a night has also been linked to an increased risk of cancer, according to certain studies. Colorectal cancer risk was observed to increase in older persons who slept less than seven hours a night, especially those who were obese or snored regularly. Long sleep duration has been linked to an increased risk of primary liver cancer and breast cancer, particularly the estrogen-dependent subtype.
Even more difficult to assess than sleep time is sleep quality, especially over the long term, which makes it difficult to correctly determine its implications on cancer risk.
Fragmented sleep has been shown to enhance tumor growth and progression in mice. More than 10,000 adults over the age of 50 were included in an observational study that indicated a greater cancer risk in those who assessed their sleep quality as poor or average.
More than 4,000 women took part in an observational study that discovered a link between insomnia and the severe form of breast cancer called triple-negative. In a more limited trial, men with more frequent and severe sleep interruptions had a higher chance of getting prostate cancer than those with less severe disturbances.
More research is needed to reproduce and verify these findings, just as there was with regard to the length of time spent sleeping. The number and length of sleep disturbances, for example, may influence the probability of acquiring certain types of cancer in future studies.
The 24-hour internal clock of the human body is known as the circadian rhythm. In the brain, it is governed by the suprachiasmatic nucleus (SCN), which sends signals throughout the body to maximize activity based on the times of the day.
In the absence of artificial light, people quickly adapt to a circadian rhythm where they are up during daylight hours and asleep at night. Circadian rhythms can go out of sync with the natural rhythms of the day and night in modern civilization due to factors such as exposure to artificial light, night shifts at work, and frequent travel across time zones.
A rising body of research suggests that cancer may be linked to circadian disturbance. Cell growth and division are influenced by circadian signals, which has ramifications for the possibility of mutations and DNA damage. When the circadian rhythm is out of whack, hormone production and metabolism, as well as the immune system, might be affected.
Circadian rhythm has a profound effect on many body systems, including breast cancer, colon cancer, lung cancer, pancreas cancer, and ovary cancer. This indicates that circadian disruption has several possible ties to the development of various malignancies.
Shift workers have an increased risk of cancer because their circadian rhythms are disrupted by nighttime labor, which is commonly referred to as “shift work.” Shift employment has been deemed “possibly carcinogenic” by the International Agency for Research on Cancer (IARC).
Exposure to carcinogens may play a role in disrupting circadian rhythms that may enhance one’s vulnerability to other risk factors, according to some researchers.
Obstructive Sleep Apnea
Most research examining the link between cancer and sleeping problems focuses on obstructive sleep apnea (OSA) (OSA). OSA causes sleep fragmentation and hypoxia (lack of oxygen in the blood) because of the many pauses in breathing it causes.
In animal studies, sleep apnea-induced hypoxia and sleep disruptions have been proven to promote tumor growth. A cancer-friendly environment may be created in people due to a variety of sleep apnea effects.
Hyperoxia exacerbates these alarming side effects, such as immune system dysfunction, chronic low-grade inflammation, oxidative stress, and insomnia by reprogramming immune system cells to be less effective in fighting cancer. In many cancers, low oxygen levels are discovered, raising the possibility that sleep apnea-induced hypoxia contributes to cancer risk.
These biochemical possibilities suggesting a relationship between OSA and cancer have not yielded conclusive findings in studies.
Study after study has found that persons with moderate and severe Obstructive Sleep Apnea (OSA) have a higher risk of dying from the disease. OSA and breast cancer have been linked in smaller studies. Prostate, uterine, lung, thyroid, and kidney malignancies, as well as malignant melanoma, are all more common in people with severe OSA.
Yet not all researchers have discovered the same patterns of cancer risk or death in people with OSA and some studies have shown fewer cancer cases in people with OSA. A lack of data on which patients were receiving therapy for OSA, as well as the fact that OSA is linked to a variety of other illnesses, such as heart disease, obesity, and diabetes, could explain some of the discrepancies in the study.
Sleep and Cancer Progression
Cancer’s growth and progression may be influenced by the quality of one’s sleep. However, more research is needed to determine whether or not factors like the impact of poor sleep quality on metabolism and inflammation can influence the aggressiveness of cancer cells.
Sleeping more than nine hours each night has been linked to an increased risk of death from breast cancer and other causes in women with the disease. It has been observed that breast cancer recurrence is linked to sleep patterns that are out of sync with the body’s natural circadian rhythms.
A study on sleep and colorectal cancer found a link between shorter sleep duration before diagnosis and an increased risk of cancer mortality, but this study, like many others, simply found a link, not proof of a cause and effect.
Hypoxia and sleep fragmentation caused by obstructive sleep apnea may make tumors more likely to spread to other regions of the body and contribute to cancer progression.
Sleep and Cancer Treatment
If we learn more about the circadian rhythm, we may be able to develop more effective cancer treatments that take advantage of the patient’s sleep patterns.
Depending on the time of day the medication is administered, cancer cells may be more susceptible or resistant to the treatment. Circadian timing affects many of the proteins, enzymes, and receptors that cancer medicines aim to target on the cell surface.
Chronotherapy is a cancer treatment component that tries to optimize radiation therapy, chemotherapy, or immunotherapy in accordance with a patient’s circadian rhythm. Chronotherapy, according to some theories, could help cancer treatments kill more cancer cells while also causing less harm to good tissue than is currently possible.
Drugs based on circadian rhythm may possibly be produced in the future to combat cancers. Circadian timing, for example, has been proven to have a favorable effect on numerous types of cancer, with early-stage trials showing promising outcomes.
Cancer patients’ recovery and response to therapy may be affected by their ability to get a good night’s sleep. It has been found that women undergoing breast cancer surgery have a higher risk of problems and a longer length of hospital stay if they have difficulty sleeping.
Obstructive sleep apnea may affect the efficacy of several cancer treatments, according to studies. Since hypoxia, which is caused by respiratory problems, can interfere with the effectiveness of some chemotherapy and radiation therapies, these treatments may be rendered ineffective.
Frequently Asked Questions About Sleep and Cancer Risk
Does Sleeping With a Light on Increase Cancer Risk?
Some study suggests that exposure to artificial light at night may affect cancer risk, albeit it is not conclusive.
Inducing the body to create melatonin, a hormone that aids sleep, is an important component of the circadian rhythm. Melatonin has been shown in animal experiments to inhibit tumor growth and aid in the repair of DNA damage in cells, in addition to its sleep-promoting properties. Sleeping with the lights on could potentially disrupt natural circadian rhythms, hence increasing the likelihood of cancer development.
People who slept in a bedroom with a lot of artificial light at night were found to have a higher risk of prostate cancer, but a lower risk of breast cancer. A lot more research is needed to understand whether or not light exposure during sleep increases the risk of cancer, given these conflicting results.
Can You Get Cancer by Sleeping Next to Your Phone?
Sleeping near to your phone does not increase your cancer risk. The sort of energy from cell phones, called non-ionizing radiation, does not cause DNA damage; instead, its only recognized biological effect is warmth. Studies of cell phone users have revealed no evidence of an increased risk of brain tumors or any other type of cancer in this population.
Despite the fact that there is no conclusive evidence linking cell phones to cancer, several experts advise against using your phone for extended periods of time while standing next to your head. Keeping your phone in a drawer or on a nightstand may be the best option.
In addition, while it is not known to cause cancer, technology in the bedroom might induce sleep interruptions, so it may benefit your sleep if you don’t bring your phone to bed with you.
Does Sleeping With a Bra Cause Breast Cancer?
There is no link between wearing a bra while sleeping and an increased risk of cancer. Studies have shown that wearing a bra while sleeping does not increase one’s risk of developing breast cancer in any way, and there is no reasonable biological explanation for why this may produce the DNA changes in cells that are needed to start cancer.
Sleep and Cancer Caregivers
While caring for a loved one with cancer, carers face their own sleep issues. In a research, 89 percent of breast cancer patients’ carers reported difficulty sleeping.
There are several factors that might contribute to carers’ sleep problems, including interruptions during the night to offer care, an increase in stress or worry, or a lack of time to tend to one’s own health. In addition to compromising their own health, sleep deprivation can exacerbate melancholy and impair their capacity to offer high-quality care.
A stable sleep routine is essential for carers to maintain their own well-being, as well. Caregivers may benefit from the assistance of other family members, friends, or local groups who can assist with some aspects of caregiving, allowing them to dedicate more time to their physical and emotional health.
Long stretches of shift work may increase cancer risk.
Cancers of the breast, colon, ovaries, and prostate may be more likely to occur if the body’s “biological clock” is disrupted. Working overnight hours and being exposed to light for a long period of time might diminish melatonin levels, which can encourage cancer growth.
Maintaining regular cancer screenings, such as mammograms and colorectal cancer testing as suggested by your doctor is essential,” adds Ruble.
Cancer therapy’s side effects and emotions can disrupt sleep.
Anxiety, despair, exhaustion, digestive issues, breathing issues, hot flashes, night sweats, and pain can all prevent you from getting to sleep and staying asleep when you’re receiving cancer treatment.
Do the following: Inform your physician of your sleep deprivation. Request that if you’re in the hospital, your sleep interruptions be reduced. Relaxation techniques and cognitive behavioral therapy can aid in alleviating stress. Maintain consistent sleep and waking schedule. Get outside or sit by a sunny window during the day to help reset your body clock and restrict your intake of caffeine.
Insomnia can bother cancer survivors for years and even decades.
If you’re going to be successful in school or at work, Ruble argues, you need enough sleep. In young survivors, we’re discovering sleep issues, and we’d like to know if they play a role in their academic difficulties.”
Do the following: The long-term adverse effects of treatment may have a part in the sleep issues of survivors, but activities that disrupt sleep may also play a role, according to Ruble. A lack of exercise and staying up late to play video games or watch television can also get in the way, she adds.
Ways to manage sleep problems
If you’re having trouble falling asleep, make an appointment with your doctor or nurse practitioner so they can help you. You and your medical team can take efforts to help you sleep better again.
- Tell your doctor about problems that interfere with sleep. Getting relief from pain or other symptoms like urine and bladder issues or diarrhea may help you sleep better.
- Cognitive-behavioral therapy (CBT) and relaxation therapy may help. Relaxation can be achieved through the use of these modalities. Even a CBT therapist can help you learn how to replace negative sleep beliefs with positive ones. Other methods that may be of use include deep breathing, visualization, and self-hypnosis, to name just a few.
- Set good bedtime habits. Only go to bed when you’re tired, in a dark, quiet room, on a comfy mattress. Take a break from bed if you can’t fall asleep, then return to bed when you’re ready to go back to sleep. Two or three hours before you want to retire to your bed, put away the electronics. Before going to bed, try not to overindulge in food or drink. Even while it’s critical to stay active throughout the day with regular exercise, doing so just before bedtime may make it more difficult to fall asleep.
- Sleep medicine may be prescribed. If nothing else works, your doctor may recommend a short-term course of sleep medication. The type of sleep medication provided will depend on your individual condition (such as difficulty falling or staying asleep), as well as any other medications you are currently taking.
Talking with your health care team about sleep problems
Make a list of the questions you want to be answered before you go. You might want to include the following on your list:
- What’s going on with my sleep?
- Why should I contact you about this issue?
- What can I do to get a better night’s sleep?
- I’m having trouble sleeping, and I’d like to know if you know of someone that could help.
- In your opinion, should I consider taking a sleep aid?