The food that you eat can dramatically impact the quality of sleep that you get. Food isn’t just food—it’s information. And the types of food that you eat, along with the nutrients they contain (or lack thereof), automatically incite processes that determine what your body, health and sleep will look like.
Not only that, but the environment in your belly itself can either make or break getting a good night’s sleep. Upwards of 95 per cent of your body’s serotonin is located in your gut.
Your sleep cycle, or circadian timing system, is a true built-in 24-hour clock that’s not much different from the clock on your cell phone. There are certain times of day when your body is designed to release specific hormones. This circadian timing system, along with
the scheduled release of hormones, helps to control your digestion, immune system, blood pressure, fat utilization, appetite and mental energy, among other activities.
Your circadian timing system is regulated by the suprachiasmatic nucleus, a small group of nerve cells found in the hypothalamus of your brain, considered to be the master gland of your body’s hormonal system. It controls your body’s hunger, thirst, fatigue, body temperature and sleep cycles by acting as a master clock.
Light actually signals your hypothalamus, and all corresponding organs and glands, to be alert and to ‘wake up’. That light exposure, specifically sunlight exposure, triggers your body to produce optimal levels of daytime hormones and neurotransmitters that regulate your biological clock.
Too little light exposure during the day and too much artificial light exposure in the evening will negatively impact your ability to sleep well at night. One of the most vital compounds affected by light exposure is the powerful neurotransmitter serotonin.
Serotonin is commonly known to help bring about feelings of happiness and wellbeing. Many antidepressant drugs focus on the function of serotonin because of its incredible effect on mood and cognition. Another important thing to note about serotonin is that it’s crucial for regulating your body’s internal clock.
Although most of your body’s serotonin is located in your gastrointestinal tract,1 serotonin production doesn’t just magically happen on its own. It’s influenced by your diet, it’s influenced by your activity levels and it’s also influenced by the amount of natural sunlight you get.
Serotonin is produced in the enterochromaffin cells of the intestinal mucosa. Once it’s released, it activates your system to increase intestinal motility. Serotonin literally helps the ebb and flow of your digestion overall.
Serotonin is the building block of the ‘get-good-sleep’ hormone melatonin. In fact, serotonin, and the health of your digestion, can impact your brain and sleep more powerfully than almost anything you can think of.
Recently, scientists uncovered that the human gut is a mass of neural tissue, filled with 30 types of neurotransmitters (just like the brain). Because of the massive amount of brain-like tissue found in the gut, it has rightfully earned the title of ‘the second brain’.2 Technically known as the enteric nervous system, this second brain consists of around 100 million neurons, more than in either the spinal cord or even the peripheral nervous system.
The gut has also been found to contain at least 400 times more melatonin than the pineal gland in your brain. Research shows that even after surgical removal of the pineal gland, levels of melatonin found in the gut remain relatively the same,3 highlighting how tissues in the gut (in particular, the enteroendocrine cells) are extremely effective at producing melatonin themselves. Consequently, the health of your gut (and everything that happens there) will always have a tremendous impact on the quality of your sleep.4
The vagus nerve, the longest nerve in the body, interfaces with the heart, lungs and other organs on a pathway straight to your brain. What researchers at UCLA were shocked to find was that around 90 per cent of the fibres in the vagus carry information from the gut to the brain and not the other way around.5 The environment in your gut and the health of your gut is a primary system calling the shots with your brain function.
Your belly is driving your brain
Researchers at UCLA also discovered that the trillions of bacteria in your gut are continuously communicating with your enteric nervous system,5 and researchers from the California Institute of Technology (Caltech) reported that certain bacteria in the gut, referred to as the gut microbiome, play an important role in the production of serotonin.6
These bacteria, referred to as friendly flora, have tremendous relevance to our health and in controlling the opportunistic bacteria that can cause a lot of damage if things get out of sorts.
A study of what happens to your intestinal flora due to irregular sleep patterns was published in the journal Cell.7 Researchers discovered that your circadian timing system influences your bacterial balance. Common experiences like jet lag were enough to create bacterial dysbiosis in the gut that, in turn, leads to metabolic disorders.
In their study, the researchers analyzed faecal samples from people before, during and after bouts of jet lag from a 10-hour flight spanning multiple time zones. They found that the jet-lagged participants showed an increase in a type of bacteria known to be more prevalent in people with obesity and diabetes. The levels of these microbes dropped back to normal once the travellers got back to a regular sleep cycle.
It’s also been found that your gut bacteria have a circadian timing system and that there’s a virtual ‘changing of the guard’ that happens every night to help keep the good guys in control of your ‘ship of state’. If you don’t sleep or don’t sleep well, it gives opportunistic bacteria a chance to take over your gut (and, thus, your brain).
Sleep deprivation has been proven to lead to poorer food choices and overeating, both of which serve to keep the unfriendly bacteria in control.
On a popular episode of my podcast, New York Times bestselling author Sara Gottfried, MD, shared her insights on how things like diet soda can wreak havoc on your gut microbiome.
Soda is highly processed and bad enough for you as it is, but as she also said, “Diet soda may be even worse for you than regular soda—in terms of what it does to your microbiome and metabolism. It can break your metabolism.”
Eat more good-sleep nutrients
When it comes to getting the nutrients you need to keep your body and sleep healthy, remember this: Food first, then supplement.
Here are some important good-sleep nutrients you need to ensure you’re getting on a regular basis and the best foods to find them in. It should go without saying that these foods ideally should be organic and minimally processed.
Selenium. A deficiency in selenium could play a role in sleep abnormalities.8 It’s also critical for immune system and thyroid function. With selenium, a little can go a long way.
Excellent sources: Brazil nuts, sunflower seeds, beef, oysters, chicken, cremini mushrooms
Vitamin C. Data from the US National Health and Nutrition Examination Surveys (NHANES) 2005–2006 revealed that people with low blood levels of vitamin C had more sleep issues and
were more prone to waking up during the night.9
Excellent sources: superfoods like camu camu berry, amla berry and acerola cherry, plus everyday foods like bell peppers, green leafy vegetables, kiwi fruit, strawberries and citrus
Tryptophan. This critical nutrient is the precursor to your body’s serotonin production.
Excellent sources: turkey, chicken, eggs, sweet potatoes, chia seeds, hemp seeds, bananas, almonds, yoghurt, leafy greens
Potassium. A study from the University of California at San Diego found that potassium may be helpful for those who have trouble staying asleep.10
Excellent sources: while bananas are often touted as the best source of potassium, there are far better sources (especially if you want to avoid excess sugar), including leafy greens, potatoes, dulse (a mineral-rich sea vegetable), broccoli, cremini mushrooms, avocados
Calcium. A pair of Japanese researchers published a study showing that disturbances in REM sleep were linked to calcium deficiency.11
Excellent sources: kale, collard greens, mustard greens, sardines, sea vegetables, sesame seeds
Vitamin D. According to researchers at Louisiana State University, there may be a strong correlation between vitamin D deficiency and excessive daytime sleepiness.12 Others have linked the deficiency to the world epidemic of sleep disorders.13
Excellent sources: swordfish, salmon, tuna, mackerel, shiitake mushrooms, oysters, exposure to natural sunlight (or supplement with D3)
Omega-3 fatty acids. A study conducted by the University of Oxford found that omega-3s can help you get deeper, more restful, sleep.14
Excellent sources: chia seeds, pumpkin seeds, hemp seeds, walnuts, halibut, salmon, flax seeds; as excessive heat can damage these oils, opt for cold-processed oils like flax oil, fish oil and krill oil from a reputable brand
Melatonin. Some foods actually have small amounts of melatonin in them, and some foods have been found to help raise your body’s production of melatonin.15
Excellent sources: tart cherries, but there are also small amounts in walnuts, root ginger, asparagus; foods that naturally boost your body’s melatonin levels include pineapples, tomatoes, bananas, oranges
Vitamin B6. This essential vitamin helps modulate your body’s stress response and relaxes your nervous system.
Excellent sources: bananas, yoghurt (sugar-free and organic), cashew nuts, peanut butter, almonds, avocados, fish, tomatoes, spinach, sweet potatoes, sea vegetables, eggs
Probiotics. As supplements, these are very popular nowadays, but many fermented foods eaten by cultures known for their longevity also provide the beneficial flora that help support healthy digestion.
Excellent sources: sauerkraut, kimchi, pickles, miso, yoghurt (dairy and non-dairy), kefir (dairy and non-dairy), kombucha tea
Prebiotics. These are essentially compounds that aid the growth or activity of probiotics within your system.
Excellent sources: Jerusalem artichokes, raw garlic, raw/cooked onions, dandelion greens, asparagus.
Mighty magnesium. Magnesium is a certified antistress mineral. It helps to balance blood sugar, optimalize blood circulation and blood pressure, relax tense muscles, reduce pain and calm the nervous system.
Because it has so many functions, it tends to be depleted from our bodies rather quickly.
Magnesium deficiency is likely the number-one mineral deficiency in the world today. Estimates show that upwards of 80 per cent of the population in the US is deficient in magnesium.
Getting your magnesium levels up can almost instantly reduce your body’s stress load and improve the quality of your sleep.
A study carried out by researchers from the Beth Israel Deaconess Medical Center in Boston, Massachusetts, showed that people deficient in magnesium are twice as likely to die prematurely.16
In addition to the proven impact magnesium has on your body, one of the central symptoms of magnesium deficiency is chronic insomnia. Simply getting your magnesium levels up can have a huge impact on your sleep quality very quickly.
Because of our high-stress world and the way magnesium is used up in the body, food alone is not likely to solve the issue of magnesium deficiency—and supplementation may not be the best method to get your magnesium levels up either. Research has shown that a large percentage of magnesium is lost in the digestive process.
High-quality supplementation can be helpful in small amounts, as can a diet high in magnesium-rich foods. But the most effective method of safely and effectively boosting your magnesium levels is through topical application onto your skin.
The fact that your body can absorb magnesium transdermally (through the skin) has been known for hundreds of years. It’s long been known, for instance, that taking a bath in Epsom salts is great for eliminating pain, reducing stress and getting a good night’s sleep. Epsom salt is actually a form of magnesium called ‘magnesium sulphate’.
Today, radically better forms of topical magnesium have been developed. Things like magnesium bath flakes and standard magnesium oils are usually 20 per cent absorbable at best. Again, because a large percentage of magnesium is lost in the digestive process, the ideal form of magnesium is transdermal from supercritical extracts.
Change your food, change your sleep
Some of the things clinically proven to damage or disorient your gut microbiome are:
- Agricultural chemicals (pesticides, fungicides, rodenticides)
- Processed foods: their excessive sugars are known to feed disease-causing bacteria
- Haphazard or repeated antibiotic use
- Chemical food additives and preservatives
- Chlorinated water. Chlorine is a known antibiotic and, while it’s excellent when used in household cleaning products, even small amounts of it ingested can damage your bacterial cascade, so it’s best to get yourself a water filter that removes chlorine if your municipality uses it.
Wake up to sleep well
Our eyes have special light receptors that send information to the centre of the brain (where your hypothalamus is) to trigger the production of more serotonin. This is happening day in and day out when we’re living in sync with nature and our body clock is set to the right time. However, if we’re not getting enough exposure to natural light, our serotonin production—and our health—is going to suffer.
In his book The Mind-Body Mood Solution (Rodale Books, 2010), clinical psychologist Jeffrey Rossman, PhD, states that “many of us are not aware that we are light-deprived and suffering from the effects of light deprivation. Because of our eyes’ extraordinary ability to adapt to changes in brightness, we tend not to be aware of how little light we actually receive when we are indoors. Typical indoor lighting is 100 times less bright than outdoor light on a sunny day. Even a cloudy day delivers 10 times more brightness than ordinary indoor lighting.”
A recent study that focused on the sleep quality of day-shift office workers revealed some shocking results. When compared with office workers who have direct access to windows at work, the office workers who didn’t have access to windows got 173 per cent less exposure to natural light and, as a result, slept an average of 46 minutes less each night. This sleep deficit resulted in more reported physical ailments, lower vitality and poorer sleep quality. In contrast, the office workers with more natural light exposure tended to be more physically active and happier, and had an overall higher quality of life.1
Adapted from Sleep Smarter by Shawn Stevenson (Hay House UK, 2016), available from www.hayhouse.co.uk for £11.69