Getting a good night’s sleep is one of the most important things that we can do to boost our physical and mental health. Good sleep has been linked to numerous benefits, such as a better functioning immune system and lower rates of anxiety and depression. However, on the other hand, there are many negative effects from lack of sleep. Researchers are continuing to explore ways that better sleep may benefit us, including working on establishing a link between poor sleep patterns and an increased risk of developing certain types of cancer. Although many people do not know about this link between sleep and cancer, there is a growing awareness within the scientific and medical community that if we can boost sleep quantity and quality, we can potentially reduce the risk of cancer.
How Sleep Impacts Your Susceptibility to Cancer
Scientific research has demonstrated that numerous behaviors and lifestyle choices can lead to heightened cancer risks. For example, cigarette smoking increases the risk of developing lung cancer 15-30 times compared with non-smokers, according to the Centers for Disease Control and Prevention. Similarly, obesity has also been linked to an increased risk of certain cancers, including liver and gallbladder cancer.
However, in recent years, attention has been turned to a lesser-known behavioral link to cancer: sleep. As a result, sleep and cancer, or more specifically a lack of sleep, have become an interesting topic of conversation and research with oncologists. This research has looked at the wide range of lack of sleep effects and steps that can be taken to counteract them to effectively prevent cancer.
#1 Sleep and Cancer Link: Natural Killer Cells
Natural killer cells, also known as NK cells, are white blood cells that play an important role in our immune system. Not only do they kill cells infected with a virus, but they also play a critical role in preventing cancer. In his book, Why We Sleep, Matthew Walker states that natural killer cells can punch a hole in the outer surface of cancer cells. After that, the NK cells inject a protein that destroys the cancer cells' ability to replicate and invade nearby tissue.
We need NK cells in order to achieve optimal immune function, but unfortunately, if we don’t get enough sleep, the quantity and efficacy of our NK cells plummet. According to one study, even one night of sleep deprivation reduces NK cells' effectiveness to roughly 70 percent. If these killer cells are less numerous and less effective, they will be less able to kill off cancer cells and viruses, again underscoring the fact that sleep and cancer are closely interconnected. Therefore, it’s essential that we prioritize sleep so that we can maintain the function of our NK cells.
#2 Sleep and Cancer Link: Cellular DNA Repair
As we go through life, our bodies age and show certain signs of aging or damage. Some of this damage is visible to the naked eye, like wrinkles, and some of it is less visible, on the cellular DNA level. Fortunately, our body actively works to repair this damage, with much of this repair occurring while we’re sleeping.
It’s not entirely clear why cellular DNA repair happens more efficiently during sleep, but researchers do know that not getting enough sleep can be detrimental. If we don’t get enough sleep, cellular DNA repair will simply not happen as effectively, and it can cause damage to build up over time.
Cellular DNA damage does increase one's risk of developing a wide range of cancers, many of which result from DNA mutations. Therefore, one could logically argue that if this repair does not happen due to sleep deprivation, then cancer risks could rise.
#3 Sleep and Cancer Link: Sleep Duration
Sleep duration refers to the amount of time that you sleep each night. Most people believe that targeting eight hours or more of sleep each night is important for long-term health. But, risks of poor outcomes, including cancer, seem to skyrocket when people regularly get less than 8 hours of sleep each night. For example, one study found a statistically significant and elevated risk of stomach cancer for chronically sleep-deprived patients.
#4 Sleep and Cancer Link: Melatonin Production
There are many reasons why people report having challenges sleeping. But, one group that is persistently plagued by poor sleep patterns and bad quality sleep is shift workers. These workers often work under bright factory lights during hours when their natural circadian rhythm would be signaling them to sleep. They are then forced to scramble to catch limited shut-eye during daylight hours.
This leaves them sleep-deprived, and there are numerous physical and psychological effects of sleep deprivation. It also negatively impacts their melatonin levels. Recent oncological research has shown the benefits of using melatonin in conjunction with radiation and chemotherapy. According to this study, Melatonin seems to have an inhibitory effect on tumor growth. Therefore, it is not a stretch to believe that if melatonin is artificially suppressed through sleep deprivation, then cancer risks may skyrocket. Again, sleep and cancer seem to be tightly interconnected.
Important Takeaways
There are natural ways to reduce your risk of cancer. One of these ways is by boosting your quantity and quality of sleep. Increasingly, research has shown that there is a link between poor sleep and cancer. So if we can break this link by encouraging better sleep practices, we can reduce the risk of cancer and see an improvement in quality of life.
