It is well-researched that the quality of our sleep can have a profound impact on our health. And newer research suggests a multi-faceted relationship between cancer and sleep. Associations are seen between chronically lower sleep quality and the risk of cancer. Additionally, cancer and the side effects of its treatments can affect our sleep quality.
We are offering a two-part blog series that will explore factors that affect the most restful hours of our day. In Part 1 of this blog post, we consider the relationship with nutrition, diving into current research and giving practical tips to support a better night’s rest. Part 2 will look at other lifestyle factors affecting sleep and discuss strategies to create a supportive sleep environment.
Sleep plays a significant role in our overall health and well-being, and its relationship with nutrition is quite complex. For example, certain foods and drinks can make it easier to fall asleep but harder to stay asleep. On the other hand, getting enough sleep has an influence on our bodies and our eating behaviour.
Let’s explore some of the aspects of this connection.
Nutrition provides our body with nutrients, vitamins, and minerals. These nutrients are necessary for certain functions and processes within our body, including sleep.  Nutrition science is complex; however, we are starting to see associations in the research between overall quality of the foods we consume and important hormonal processes in our body such as sleep. A well-balanced diet, with plenty of vegetables, fruit, lean proteins, and high-fibre foods can improve sleep quality. In the research, the DASH and the Mediterranean diets have shown benefits for improved sleep. When we compare these dietary approaches to the recommendations for a cancer-protective approach, we can see many similarities, including:
- A focus on plant-based eating – meaning most of our foods coming from plants
- Choosing a variety of fruits and vegetables each day with an assortment of colours
- Selecting high fibre options such as: whole grain breads and crackers, beans and lentils, and brown rice
- Balancing macronutrients both during the day and in meals, and getting a balance of protein, carbohydrates, and fat
- Choosing less refined and less processed foods when possible
- Timing meals to give the body 2-3 hours of digestive time before going to bed
Foods containing tryptophan, melatonin, and phytonutrients may have positive results for better sleep quality and quantity. This is likely due to an influence on serotonin and melatonin activity. 
Other studies show that the high antioxidant capacity of kiwifruit may help to reduce oxidative damage, and this may in turn improve sleep quality. Additionally, kiwi is one of the few fruits that has a high serotonin concentration, which may also be helpful for sleep. 
How Sleep affects Hunger
Not getting enough sleep can lead to higher food consumption without an increase in exercise. Poor sleep also tends to create a desire to consume high-calorie foods that offer less nutritional benefit.  The research suggests these effects are due to the connection of our sleep hormone pathway and hunger hormones. Normal production of leptin and ghrelin, hormones that help regulate appetite and hunger, can be affected even after short periods of inadequate sleep. 
Coffee is often used to promote daytime alertness however, if the caffeine from our coffee is still active during sleep hours, it can reduce our quality of sleep leading to lower levels of morning alertness. Adenosine is a chemical that promotes sleep and caffeine blocks adenosine receptors. Caffeine can also interfere with our circadian melatonin rhythms, which delays the ability to fall asleep. The half-life of caffeine is 3-7 hours, which indicates the amount of time our body needs to metabolize half the caffeine you have consumed. As such, if we drink caffeinated tea or coffee in the afternoon, this could affect our ability to fall asleep even many hours later. Decaffeinated coffees and teas have less caffeine than the regular ones but they still contain some caffeine.
Alcohol can change both the length and quality of our sleep.  Alcohol can also affect the amount of time it takes to fall asleep. Consuming alcohol may mean less waking through the first part of the night but it can have a disruptive effect on the rest of the night, with fragmented sleep and frequent waking. Larger amounts of alcohol can significantly increase the amount of non-REM sleep and reduce the amount of REM sleep, meaning we may feel less refreshed and more fatigued the following day.
We’re still learning many aspects of the connection between nutrition and sleep. However, we do know that creating a nutrient-dense diet can be cancer-protective, can contribute to overall health, and may improve the quality of our sleep. To explore what would work best for your specific situation, reach out to our Registered Dietitians at InspireHealth for individualized support. In the coming months, we’ll be offering Part 2 of this blog and be looking at other lifestyle and environmental factors that can support a better night’s rest.
 Ikonte CJ, Mun JG, Reider CA, Grant RW, Mitmesser SH. Micronutrient Inadequacy in Short Sleep: Analysis of the NHANES 2005-2016. Nutrients. 2019 Oct 1;11(10):2335. doi: 10.3390/nu11102335. PMID: 31581561; PMCID: PMC6835726.
Frank S, Gonzalez K, Lee-Ang L, Young MC, Tamez M, Mattei J. Diet and Sleep Physiology: Public Health and Clinical Implications. Front Neurol. 2017 Aug 11;8:393. doi: 10.3389/fneur.2017.00393. PMID: 28848491; PMCID: PMC5554513.
 Binks, Hannah et al. “Effects of Diet on Sleep: A Narrative Review.” Nutrients vol. 12,4 936. 27 Mar. 2020, doi:10.3390/nu12040936
 St-Onge, Marie-Pierre et al. “Effects of Diet on Sleep Quality.” Advances in nutrition (Bethesda, Md.) vol. 7,5 938-49. 15 Sep. 2016, doi:10.3945/an.116.012336
 Greer SM, Goldstein AN, Walker MP. The impact of sleep deprivation on food desire in the human brain. Nat Commun. 2013;4:2259. doi: 10.1038/ncomms3259. PMID: 23922121; PMCID: PMC3763921.
 Spiegel K, Tasali E, Penev P, Van Cauter E. Brief communication: Sleep curtailment in healthy young men is associated with decreased leptin levels, elevated ghrelin levels, and increased hunger and appetite. Ann Intern Med. 2004 Dec 7;141(11):846-50. doi: 10.7326/0003-4819-141-11-200412070-00008. PMID: 15583226.