Eat better to sleep better!
Without even fully grasping the biological necessities of what sleep does for us, we all know that experiencing a lack of sleep for too long makes us feel irritable, moody, foggy-minded, and hungry. Our brains need 7-8 hours of sleep per night to complete its work. To understand why the right amount of sleep is so important, let’s briefly break down how the sleep cycle works.
The sleep cycle is divided into several stages (Gordon, 2013):
|Stage 2||Stage 3||Stage 4||Stage 5|
You enter a light sleep; muscular activity decreases.
|Breathing pattern and heart rate slows; decrease in body temperature.||Deep sleep begins; brain begins to generate delta waves.||Very deep sleep; rhythmic breathing patterns. Limited muscle activity. Brain continues to produce delta waves.||
Rapid eye movement (REM) stage. Brainwaves speed up, and dreaming occurs. Muscles relax and heart rate slightly increases. Breathing is rapid and shallow.
The food and cortisol connection
The glycaemic index (GI) of a food is a value that reflects how slowly or how quickly particular foods cause increases in blood sugar levels. Foods containing high amounts of refined carbohydrates or simple sugars and minimal fibre have a high GI rating, resulting in larger fluctuations in blood sugar and insulin levels. Insulin allows for carbohydrates to be absorbed into our cells as glucose. High GI foods cause cortisol levels (the body’s stress hormone) to rise. Eating packaged or highly refined, carbohydrate rich foods first thing in the morning can cause cortisol levels to over-shoot the normal range. Cortisol levels may remain high throughout the day, but more concerning, well into the early hours of the night. High cortisol levels disrupt the production of melatonin; a hormone that promotes sleep. As melatonin levels rise in the body, you begin to feel increasingly sleepy. If melatonin production is disrupted, you may experience trouble falling asleep (American Nutrition Association, 2015).
Skipping meals may be damaging to your sleep.
At any time during the day, if an individual does not eat within 5 hours of their last meal or snack, cortisol levels tend to rise. Eating late at night can result in a high cortisol output disrupting your nightly sleep cycle, especially your REM sleep. This leaves you feeling unrefreshed upon waking in the morning (American Nutrition Association, 2015).
What foods lower cortisol levels?
Foods rich in fibre, protein, and complex carbohydrates help to balance blood sugar levels, thus, keeping cortisol in-check. These foods include nuts, seeds, eggs, poultry, fish, and most vegetables. Removing highly refined and processed foods from your diet and reducing your sugar intake can help to balance your blood sugar and promote a good night’s sleep. Here is a list of foods our naturopath, Amanda Harasym recommends to be avoided:
- Soft drinks
- Chocolate bars
- Refined grain products (e.g. white bread, white pasta)
- Packaged foods (e.g. sugary cereal, sugary granola bars)
- Caffeine (or at least cut back and avoid 2-3 hours before bed)
- Fast food (e.g. fish and chips, pizza, fried chicken)
- Snacks and desserts (e.g. donuts, potato chips, biscuits, cookies)
Foods to promote a healthy sleep cycle(National Sleep Foundation, 2018):
Want a great nights sleep? Incorporate these foods into your diet
- Complex carbs: Whole-grain oat crackers with 1 tablespoon of a nut or seed butter (e.g. almond butter, pumpkin seed butter).
- Handful of nuts: Nuts are a great source of heart-healthy fats. Almonds and walnuts contain tryptophan, an amino acid needed to synthesize melatonin, the sleep-promoting hormone. Eating these nutrient-rich nuts can help increase blood levels of melatonin.
- Cottage cheese: Lean protein foods contain tryptophan which may help to increase serotonin levels. Low levels of the brain chemical serotonin are associated with poor sleep habits and may contribute to insomnia.
- Certain fruits also contribute to an increased production of melatonin. These fruits include tart cherries, bananas, pineapple, oranges, and kiwi. It is important to eat plenty of colourful fruits and vegetables, as they contain antioxidants which counteract the oxidative stress produced by high cortisol levels and sleep disorders.
Supportive sleep nutrients (Salmon, 2017):
- Vitamin D: Low levels are associated with poor sleep quality.
- Iron: Being deficient in iron can cause restless leg syndrome, where people constantly move their legs before bed.
- Calcium: Calcium helps the brain to use tryptophan, an amino acid that contributes to the production of both serotonin and melatonin, inducing sleep.
- Magnesium: Magnesium helps to nourish the nervous system and promote muscular relaxation.
- Vitamin E: This vitamin helps combat restless leg syndrome, making it easier to fall asleep.
- B vitamins: The B complex vitamins help to manufacture the amino acid tryptophan, the brain chemical which helps to induce sleep.
If you are needing a diet overhaul and suffer from poor sleep, it may be worth seeking help from a health professional, such as a Naturopath or Nutritionist who can help to adjust your overall diet, balance your blood sugar, and boost your nutrient levels to help support healthy sleep habits. Other lifestyle suggestions may be recommended, and specific nutrient supplementation or herbal therapies may also be useful.
American Nutrition Association (2015). Eat your way to better sleep. Retrieved from http:// http://americannutritionassociation.org/newsletter/eat-your-way-better-sleep.
American Psychology Association. (2018). Why sleep is important. Retrieved from http:// http://www.apa.org/topics/sleep/why.aspx.
Field, A. Why sleep is so important [Harvard Business Review]. January, 2009. Retrieved from http://www. https://hbr.org/2009/01/why-sleep-is-so-important.html.
Gordon, A. Your sleep cycle revealed [Psychology Today]. July 2013. Retrieved from http:// https://www.psychologytoday.com/blog/between-you-and-me/201307/your-sleep-cycle-revealed.
Salmon, L. Tired? The vitamins and minerals your body needs to help you sleep better [BT blog]. (2017). Retrieved from http:// http://home.bt.com/lifestyle/health/sleep/tired-the-vitamins-and-minerals-your-body-needs-to-help-you-sleep-better-11364098011805