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We know that diet is a pillar of health. Our diet is also an important basis for healthy sleep. Cultivating eating habits that are right for you and help you get a good night’s sleep is not one size fits all. There is no such thing as a “diet” that is good for sleeping, and there is a wide range of foods that go well with a sleep-inducing diet.
The Mediterranean diet, with its abundance of unprocessed whole foods, an emphasis on vegetables, fruits, moderate whole grain consumption, and healthy fat and protein sources, has been linked to higher quality sleep, also in this 2020 study of adult women in the United States.
But the short- and long-term impact of food on sleep and sleep quality is actually a fairly under-explored area of sleep and nutritional science. There is much more to be learned about how macronutrients – proteins, fat, carbohydrates, fiber, amino acids – as well as vitamins and minerals influence the sleep behavior and the quality of our night’s sleep. However, there is growing scientific evidence to show which foods can protect and improve sleep – and which foods can undermine sleep.
Protein: Protein is a natural sleep aid. Its sleep benefits include high protein foods a source of tryptophan, an amino acid the body uses to make the sleep-promoting hormone melatonin. And consuming a larger proportion of calories from protein can help you feel full at night, suppress hunger hormones, and allow you to sleep longer.
A 2020 review of recent sleep nutrition research found that higher quality sleep was associated with consuming more daily calories from protein and fewer carbohydrates and fat. And a 2016 Columbia University study found that participants who ate meals high in protein and fiber, and low in saturated fats, sugar, and carbohydrates, had better quality sleep and more time in deep sleep.
The wide range of sleep-friendly protein sources includes eggs, fish, chicken breast, broccoli, spinach, quinoa, and almonds.
Fiber: Eating a high-fiber diet can help us achieve deeper, more restful rest. High-fiber diets have been associated with less time in light sleep and more time in slow-wave sleep, the deep, very restful phase of sleep during which the body performs significant cell rejuvenation and repair. The 2016 Columbia University study found that a single day of low-fiber food intake can interfere with sleep that night.
Avocados, pears, chickpeas, lentils, oats, and dark chocolate are some of the high-fiber foods that can contribute to a sleep-inducing diet.
Magnesium: This essential mineral has powerful sleep benefits. Magnesium calms the nervous system and relaxes the muscles. It is involved in regulating the “sleep hormone” melatonin and helps the body maintain healthy vitamin D levels, which enables more restful, quality sleep. Magnesium also maintains healthy levels of GABA, a neurotransmitter that promotes sleep. Many people lack adequate magnesium, and low levels of magnesium have been linked to insomnia. Since magnesium is not produced in the body, we need to add foods that provide it to our diet.
Good food sources for magnesium are bananas, spinach, avocados, brown rice, tofu, and cashews.
Potassium: Potassium promotes healthy blood circulation and digestion, while also helping to relax muscles, which contributes to better sleep. Research has shown that increased potassium levels (in this study, from supplementation) are associated with fewer nocturnal awakenings.
Foods rich in potassium include leafy greens, potatoes, bananas, mushrooms, and legumes.
Vitamin D: Vitamin D helps regulate the circadian clock that controls the daily sleep-wake cycles and can promote longer, more restful sleep. A lack of adequate vitamin D has been linked to short sleep times and more restless sleep. Research also suggests that vitamin D deficiency can increase the risk of obstructive sleep apnea.
Sunlight is the best source of vitamin D. Our bodies produce vitamin D in response to exposure to sunlight. Food sources for vitamin D include fatty fish, fish oil, egg yolks, dairy products, and D-fortified foods.
Omega-3 fatty acids: These polyunsaturated fatty acids are so-called essential fats. Our body does not produce omega-3 fatty acids; we need to get them from food sources, including food supplements. Research shows that omega-3 fatty acids are linked to better sleep quality and can help us fall asleep faster. Some animal research has found that a deficiency in DHA, one of the three main types of omega-3 fatty acids, can interfere with nighttime melatonin production.
Many species of fish are rich in omega-3 fatty acids DHA and EPA, including anchovies, blue bass, mackerel, wild salmon and tuna. Nuts and oils are powerful sources of Omega 3 ALA, including walnuts, flaxseed and flaxseed oil, canola oil, and soybean oil.
Water: It’s important not to overlook hydration when it comes to promoting healthy sleep. Water is a macronutrient, and staying hydrated throughout the day is important to get a good night’s sleep. It’s a one-way street here: dehydration can negatively affect sleep, and poor sleep can dehydrate us.
Even if we sleep well, we lose about a liter of water overnight. The first thing I recommend when you wake up is to drink 12-16 ounces of room temperature water to make up for the loss of water overnight. And keep off with caffeine for 90 minutes in the morning. Caffeine is a diuretic, and drinking it right after you wake up is counterproductive to morning hydration.
Which foods should we restrict in our diet to protect our sleep?
Sugar is high on this list. A sugary diet causes several sleep problems. Sugar consumption is linked to restless sleep and more frequent night awakenings. Sugar stimulates the appetite, which can lead to more nightly eating, which disturbs our rest. Sugar contributes to inflammation and inflammation disrupts sleep. And sugar is harmful to gut health. Our gut microbiome plays a role in regulating sleep that we are only just beginning to understand, and it is becoming increasingly clear that protecting the health of our gut can have a profound impact on sleep.
Saturated and trans fats. Fats play an important role in healthy eating and good sleep, but the type of fat in our diet plays a big role. A diet high in saturated fat has been associated with easier sleep, accompanied by more frequent nighttime wakes. Saturated and trans fats, often found in highly processed foods, are linked to weight gain, inflammation, and undermine sleep.
A healthy diet makes a significant contribution to consistent sleep quality. Together with a healthy sleep schedule, regular exercise and a sleep-inducing bedroom, your varied whole-food diet can improve your night’s sleep.