Can My Sleep Habits Affect My Cancer Risk?

Most people associate a cancer diagnosis with bad genetics or simply bad luck. That makes it seem like the Universe is somehow conspiring against us, and there is little we can do about it. We are hopeless pieces of a wheel that spin stopping at the unlucky one. This perspective on cancer leaves us with little room for empowerment and action. If we believe it is a mere question of luck or lack of, then there is not much we can do about it. We choose the most obvious course of action and go to our conventional doctor; from then on, it’s up to them to fix us.

But what if we told you there are far more things you can do to reduce your cancer risk than you thought before? What if you actually have the power to do something about your life, right now, that could highly contribute to minimizing the chances of you having cancer? Would you take the reins of your life and start modifying what can be modified?

Which modifiable lifestyle factors play a major role in cancer risk and cancer deaths, is what researchers set out to find. 

Study Shows Nearly Half of Cancer Cases Are Caused by Lifestyle Factors

A study published in 2018 estimated that about 660,000 (42%) of all incident cancer cases and 265,000 (45%) of all cancer deaths in the United States in 2014 were attributable to potentially modifiable risk factors.

What personal factors increase the risk of cancer?

Some of the authors of this study decided to delve deeper into the “information on risk factors associated with specific cancer types and the magnitude of associations,” as data can evolve considerably over time and more information is always becoming available. The researchers analyzed 18 modifiable risk factors across 30 types of cancer and published their findings in 2024. 

The study found that in 2019, an estimated 40.0% (more than 700,000 new cancer cases) of all incident cancers (excluding nonmelanoma skin cancers) and 44.0% (more than 262,000 deaths) of all cancer deaths in adults aged 30 years and older in the United States were attributable to the evaluated risk factors. 

What Cancer Types Are Most Preventable?

These researchers also evaluated cancer types, and for 19 out of the 30 cancer types analyzed, more than half of the cancer cases and deaths were attributable to the potentially modifiable risk factors considered in this study. The highest associations were found for:

• Lung cancer 
• Female breast cancer 
• Skin melanoma colorectal cancer 
• Liver 
• Esophageal 

Key Lifestyle Factors That Impact Cancer Risk: Steps You Can Take

Besides some of the most obvious and easily modifiable factors mentioned above, such as smoking and alcohol consumption, there are several other activities and steps you can take towards better health and reducing your risk of cancer.

Let’s start with the top five factors identified in this study, and then we will introduce to some of the lifestyle modifications we teach our students at An Oasis of Healing. 

What Can We Do to Reduce Our Risk of Getting Cancer?

Lack of sleep, cigarette smoking, alcohol, excess body weight, physical inactivity, poor diet and UV radiation exposure – all of these factors are modifiable and affect your health and risk of chronic illnesses such as cancer. However, there are other lifestyle factors that you can start changing and optimizing today to improve your health and speed up any healing processes within your body.

One of the changes we teach our students is sleep. Sleep is one of the most important factors in health and healing.

Sleep and Circadian Rhythm

Unfortunately, sleep is one of those topics that is rarely touched upon. Circadian rhythm regulation even less, because most people have never heard of it, but both play a huge role in health and healing. We spend about one-third of our lives sleeping, yet we have very little understanding of why we sleep and why it is such an important factor for human health.

Why Sleep Matters: Surprising Statistics

Maybe some numbers will make you reconsider the relevance you give to sleep:

• One night sleeping 4 hours (relative to 8 hours of sleep) leads to a 70% reduction in NK cells¹! Research shows an association between insufficient sleep and malignant tumors^2,3. In mice studies, fragmented sleep accelerates tumor growth and progression: sleep-deprived mice showed a 200% increase in speed and size of cancer growth (the cancers became more aggressive)⁴.
• A study of 23,620 middle‐aged participants found that individuals who on average slept less than 6 hours had a 43% higher risk of cancer compared with those who slept 7 to <8 hours⁵.

Night Shift Work and Cancer Risk

For good reason, in 2007, the World Health Organization IARC (International Agency for Research on Cancer) concluded that night shift work is a probable carcinogen to humans based on animal and epidemiological studies⁶. This means that night shift work increases the risk of cancer. According to the author of a 2023 study titled A Narrative Review of the Carcinogenic Effect of Night Shift and the Potential Protective Role of Melatonin: “The contributing factors for this are hypothesized to be directly related to circadian rhythm and decreased melatonin production which are thought to be oncogenic in nature⁷.” For circadian rhythm regulation, one of the most impactful things you can do is go for a 20-30 minute walk outside after sunrise, upon waking.

Sleep Deprivation and Genetic Impact

Furthermore, studies evaluating the effects of one week of subtly reduced sleep (sleep-restriction condition 5.70 h versus control condition 8.50 h sleep) distorted the activity of 711 genes – these genes were up- or down-regulated by insufficient sleep⁸.

• About half increased expression – genes linked to chronic inflammation, cellular stress, and factors that cause cardiovascular illness
• Other half, diminished expression, or shut down entirely – genes that maintain stable metabolism and optimal immune response

What about one week, one month, or years of improper sleep and circadian rhythm disruption?

Supporting Health Through Quality Sleep

Sleep is when your body heals and regenerates. Aim for 7-8 hours of quality sleep each night to support your immune system, brain, and metabolism.

Prioritize your sleep, the time when your body heals and regenerates, and take steps toward promoting circadian rhythm regulation. Good sleep will improve immune function, metabolism and brain health. The authors of a study published in 2016 stated that “sleep is essential for many vital functions including development, energy conservation, brain waste clearance, modulation of immune responses, cognition, performance, vigilance, disease, and psychological state⁹.”

Tips to Optimize Sleep

What can we do to sleep better? We will go over a list of a few things you can do to start getting a better night of sleep.