• We need sleep in order to clear out waste and cleanse the brain from harmful substances
  • Recommended duration of sleep at night should be 7-8 hours of sleep
  • Lack of sleep may ultimately lead to risks of cancer: breast cancer in women and prostate cancer in men
  • Lack of sleep can have a detrimental effect on metabolism which can lead to weight gain and diabetes Types II
  • Receive adequate uninterrupted sleep and reduce exposure to artifical light at night

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What is sleep and why is it important?

Sleep is defined as an altered state of consciousness, inability to move your body as a result of the inhibition of voluntary muscles and inhibition of sensory processing activity in the brain. During sleep, the body excretes waste and toxins from the brain [1,2]. Thus, the need to sleep is not only important by getting a good nights rest, but removing harmful substances and waste from the brain. As a result of decreased sensory activity in the brain, it is able to clear up debris and waste since it is not busy processing sensory information. The brain acts as an “on” and “off” switch by means of tackling one task or function at a time. During the day when we are awake, the brain processing our surroundings and during sleep, it clears out waste [1,2].

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How Long Should I Sleep For?

When we sleep, we go through two main phases of sleep which are known as Non-Rapid Eye Movement (NREM) and Rapid Eye Movement (REM) which occur in a normal eight-hour sleep cycle. The first stage NREM 1 is the stage between wakefulness and sleep, also known as drowsy sleep. This stage typically lasts about 5 to 10 minutes. During NREM 2 (stage 2), physiological effects occur in the body where muscles relax, heart rate decreases and body temperature decreases. NREM 3 and 4 (stage 3 and 4) is characterized as a deep sleep (delta waves) where if an individual is awakened during this stage, the person will feel disoriented [1].

Melatonin improves immune system function and ultimately inhibits the development of cancer…

The last stage of the sleep cycle is Rapid Eye Movement sleep or REM sleep. As the name suggests, it is during this phase of sleep where the eyes rapidly move in all directions and where powerful dreams occur. On the contrary to stage 2, heart rate increases and respiratory rate increases however breathing rhythm varies [1].

A survey had been conducted targeting local city regions located within the Inland Empire to which participants of the survey were given a series of questions in which one particular question had been about sleep duration. From the total responses, over half of the participants, (56%), responded to sleeping on average 7-8 hours at night which was above average from national sleep statistics which states that on average an individual sleeps for 6.8 hours at night [8]. 

Medical doctor Gary R. Lichtenstein, at the University of Pennsylvania,  recommends that young adults (18-25 years old) and adults (26-64 years old) receive 7 to 8 hours of adequate uninterrupted sleep in order to overcome the effects of decreased physical activity and fatigue due to the lack of sleep [4].

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Lack Of Sleep And Risk Of Cancer?

When one does not obtain 7 to 8 hours of sleep they get tired easily throughout the day and yawn excessively. However, fatigue and decreased energy is not the only consequence of lack of sleep. When we sleep, the pineal gland in the brain induces the production of a hormone called melatonin at the time of the night which helps us fall asleep and regulates our sleep cycle. In addition, melatonin improves immune system function and ultimately inhibits the development of cancer and cancer cell proliferation [6].

What if melatonin is suppressed? A reduction of melatonin production has a detrimental effect on the sleep cycle and the immune system. Low production of melatonin disrupts the sleep cycle which consequently keeps the person awake at night. In addition, by decreasing fewer immune cells such as Natural Killer cells (NK cells) circulating throughout the body due to low levels of melatonin, the immune system has a challenging time fighting off diseases caused by bacteria and/or viruses.

Getting a good  night sleep is not only essential to be energetically active during the day but to also fight off cancer.

For individuals who work night shifts and exposed to light, melatonin production ceases which may lead to a higher risk of certain cancers. In women, low levels of estrogen correspond to high levels of melatonin. However, due to low levels of melatonin and high levels of estrogen, women are at greater risk of breast cancer. With regard to men, low melatonin production may lead to a higher risk of prostate cancer [6]. Thus, receiving sufficient sleep at night is beneficial from waking up and being active to ultimately preventing cancer proliferation and development.

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How Does Sleep Affect Metabolism?

During sleep, glucose metabolism is much lower during non-REM stages 2,3 and 4 than when we are in the state of wakefulness [9]. Sleep deprivation/ lack of sleep may be a contributing factor weight gain, obesity, and metabolic disorders such as Type II Diabetes [8]. Sleep deprivation/ lack of sleep can also take a toll on weight gain and obesity [8]. Studies have shown an association between increased sleep duration and decreased weight gain and vice versa [8]. These studies may suggest that sleep ultimately helps regulate weight; however, there is no direct relationship between the two.

Type II diabetes is the consequence of insulin resistance. In a normal physiological state, after eating a meal, there is much more glucose circulating in the body. As a result, in order for the cells in the body to intake glucose, our pancreatic beta cells release insulin which induces cells to intake glucose. However, when the body produces much higher insulin and it is not used properly, as a result of higher glucose levels, it may consequently lead to insulin resistance and thus the cells in the body are unable to intake glucose [9]. With more glucose unable to be used by the cells in the body and more circulating in the blood, it leads to hyperglycemia. Hence, eating before going to bed may imbalance glucose metabolism. The risk of diabetes from sleep duration is not completely understood.

It is recommended not to eat 1 to 2 hours before going to bed, exercising daily, and during the day eating foods rich in high protein and fat and most importantly get plenty of sleep during the night.

For more information on how to eat properly and exercise, visit the Nutrition and Exercise links or tabs located above.

What Can I Do To Sleep Better? 

Getting a good night sleep is not only essential to be energetically active during the day but to also fight off cancer.

Here is a list of examples that you can follow to get a good night sleep:

  • Reduce your exposure to computers/ smartphones 2 to 3 hours before bed
  • Avoid turning on light when going to the bathroom, utilize nightlight if necessary
  • Avoid eating heavy meals 1 to 2 hours before going to bed
  • Eat healthy foods (vegetables and protein), reduce your stress
  • Take melatonin supplements to increase levels of melatonin*
  • Avoid using an alarm clock
  • Relaxation techniques: Breathing in from your nose 4 seconds, holding your breath for 7 seconds and exhaling out of the mouth for 8 seconds


  1. Eugene, A. R., & Masiak, J. (2015). The Neuroprotective Aspects of Sleep. MEDtube Science, 3(1), 35–40
  2. Xie L, Kang H, Xu Q, Chen MJ, Liao Y, Thiyagarajan M, O’Donnell J, Christensen DJ, Nicholson C, Iliff JJ, Takano T, Deane R, Nedergaard M  
  3. Sleeping man and an alarm clock. [Picture]. Adapted from: https://medicalxpress.com/news/2018-03-expert-debunks-myths-restful-slumber.html
  4. Lichtenstein, G. R. (2015). The Importance of Sleep. Gastroenterology & Hepatology, 11(12), 790.
  5. Sleep cycle in an eight hour period. [Picture]. Adapted from: https://www.thefatkidinside.com/rest-recovery-sleep/main-qimg-815970ddf50025e2d176a0a9d6ed934c/
  6. Blask, D. (2009). Melatonin, sleep disturbance, and cancer risk. Sleep Medicine Reviews, 13(4), 257-264.
  7. Cancer. [Picture}. Adapted from: https://lazarangelov.academy/6-major-consequences-of-poor-sleep-quality/
  8. Sharma, S., & Kavuru, M. (2010). Sleep and Metabolism: An Overview. International Journal of Endocrinology, 2010, 270832. http://doi.org/10.1155/2010/270832
  9. Knutson, K. L., Spiegel, K., Penev, P., & Van Cauter, E. (2007). The Metabolic Consequences of Sleep Deprivation. Sleep Medicine Reviews, 11(3), 163–178. http://doi.org/10.1016/j.smrv.2007.01.002
  10. Sleep Deprivation. [Picture}. Adapted from: https://www.lifehack.org/articles/lifestyle/silent-killers-your-metabolism.html

*Please keep in mind that when taking any melatonin supplements always consult with your primary care physician or practitioner that can help you with the dosage amount and instruction on how to safely take melatonin supplements. In the case of any negative symptoms stop taking the supplements and contact your doctor right away.