How Nutrition Affects Sleep – The Expert’s Opinion

We hear all the time that what we eat can affect our sleep, from cherries to tea and so much more besides, however, how accurate is this? It’s easy to understand that eating or drinking certain things before bedtime can stop us falling asleep (as an example caffeine), however, what about the effects of introducing certain foods into our everyday diets?

We decided to ask a number of sleep and nutrition experts as to how nutrition affects sleep, with some rather interesting responses being given:

Dr Robert S. Rosenberg, Sleep Specialist

Nutrition is very important for sleep. You do not want to be consuming large meals close to bedtime. Remember your digestive tract slows way down when we go to sleep. Give yourself at least three hours before bedtime if you are going to consume a large meal.  Avoid spicy foods that increase the body temperature thus inhibiting sleep. They can also cause acid reflux. Avoid foods with a high glycemic index, especially close to bedtime. These foods cause rapid rises in glucose, that result in surges in insulin, that then cause stress hormones such as cortisol and adrenaline to be produced resulting in making it very hard to fall asleep. Watch your caffeine intake and try to avoid caffeine within 6 hours of bedtime. Avoid aged meats and cheeses as well as tomatoes and eggplant close to bedtime, they contain the amino acid tyramine. Tyramine stimulates the production of the wake promoting neurotransmitter norepinephrine.


Nutrients: Try to eat foods high in B vitamins we need B vitamins to make and maintain melatonin levels. We also need them to get rid of homocysteine, an inflammatory amino acid made from methionine in our diet that can cause anxiety do to inflammation in the central nervous system. Foods high in B vitamins include kale, eggs, poultry, and avocados. Eat foods high in vitamin E. Vitamin E has been shown to prevent leg cramps, restless legs syndrome, and hot flashes. Because it is such a strong antioxidant and is neuroprotective; it also has been found to be beneficial in preserving memory after a night of insufficient sleep.


Foods that help sleep: Based on two recent studies I would recommend tart cherries. In a recent study done, at Louisiana State University, tart cherries increased sleep time in people with insomnia by 90 minutes. Tart cherries contain melatonin and also anthocyanins. Anthocyanins are flavonoids that give the cherry its dark red color. They slow down the breakdown of tryptophan, an amino acid which goes on to form serotonin and melatonin, both necessary for sleep.


Finally foods rich in omega 3 PUFA (polyunsaturated fatty acids) such as fatty fish, flaxseed, chia, and Krill. A recent study in England demonstrated that when children were give 600mg of fish oil daily there sleep increased by one hour per night. Omega 3’s were also found to decrease anxiety levels. This is probably because, unlike the omega 6’s found in vegetable oils, which are proinflammatory;the omega 3’s have anti-inflammatory properties. Many of us are beginning to realize that in the modern diet we consume too much omega 6’s and not enough omega 3’s.


Dr Jay Goodbinder, Holistic Doctor & Nutritionist

Nutrition affects sleep in too many ways to detail them all here. however, I will describe a few.

Having a drop in blood sugar during sleep can cause a jump in cortisol. Cortisol will raise blood sugar again. As cortisol is a stress hormone, this will wake you up. Typically, this will make your mind race and make it difficult to fall asleep again. To stop this from happening, eat some protein or a high fiber carbohydrate for extended release energy, about an hour before bed. Also, your sleep wake cycle or circadian rhythm is governed by the hippocampus in your brain.


The hippocampus can be damaged by insulin spikes so again, keeping your blood sugar under control is important. Interestingly, research circles are starting to call alzheimer’s disease, type 3 diabetes. This is because one of the other main purposes of the hippocampus besides sleep wake cycle is short term memory. The hippocampus is the first area destroyed in alzheimer’s disease and one of the first symptoms is the inability to sleep. This parallels the short term memory issues that most people associate with the disease. Amino acids from protein eaten can also affect sleep. glutamate is an excitatory neurotransmitter and eating certain foods that contain a lot of it can make it difficult to sleep.


Soluble fibre eaten can feed beneficial bacteria in the gut that create butyric acid. The level of butyric acid in your colon will not only affect your gut inflammation, but will help your body produce gamma amino butyric acid or gaba to help you sleep. Obviously, gaba is a calming neurotransmitter.


Dr Kathy Gruver, Health & Wellness Expert

There is definitely a connection between food and sleep. For example, MSG is an additive in multitudes of process and packaged foods that can cause a disruption of sleep. It is excitotoxin and though it affects people differently I know when I am imbibe I am up all night with hot flashes, heart palpitations and racing thoughts. In that same vein the artificial sweeteners like aspartame can have that effect on people as well.

There are also foods that can help with sleep. Tryptophan is an essential amino acid that is found in things like the dark meat of turkey and dairy products. Tryptophan is a necessary component for sleep and can actually help us get through the night more comfortably.


Natalie Thomas-Oliveira, Certified Nutrition and Wellness Consultant

Nutrition directly impacts your sleep. All food gives you energy. Some foods give a lot (high calorie) and some give just a little (low calorie). Some provide energy quickly (carbohydrates) and some more slowly (fats and proteins). So depending on what you eat and when, there will be a direct impact on your ability to fall asleep when you want to. I advise clients to time meals throughout the day so as to not binge eat before bed. If they must eat a light snack before bed I suggest a small amount of cheese and some chamomile tea to relax and feel satiated without a sudden burst of energy right when you’re tying to fall asleep.


Rene Ficek, Registered Dietitian and Lead Nutrition Expert

Spinach, Bananas, Nuts, Seeds, Fish and Wholegrains
These foods are all high in magnesium. If you do not consume enough magnesium, chronic insomnia is one of the main, central symptoms. These foods will only work if one has a magnesium deficiency, but will be neutral if you consume enough magnesium.


Herbal Teas
Herbal teas, such as chamomile, passion flower tea and valerian, have a sedative effect and lead to a good night sleep.


Oats, Bananas, Poultry, Eggs, Peanuts and Tuna
What do these foods have in common? They are all high in tryptophan! Tryptophan works by inducing the brain chemical serotonin and melatonin, which help relax the body and prepare it for a good night sleep.


A Warm Cup of Milk
Sound like an old wives’ tale rather than sound nutrition advice? Well science now shows us that our mothers were right; drinking a warm glass of milk will indeed help you sleep better. Dairy products are rich in the amino acid tryptophan, which helps in the production of the sleep inducing brain chemicals, serotonin and melatonin. Additionally, dairy products are high in calcium and magnesium. These nutrients work together to calm the body and help relax muscles. A lack of these minerals may cause you to wake up after a few hours and not return to sleep. Calcium helps the brain use the amino acid tryptophan to manufacture the sleep-inducing substance melatonin. This combination of nutrients in dairy products explains why they are the best sleep-inducing foods.


How Soon Before Bed Should Caffeine Be Eliminated?
The stimulant effect of caffeine reaches its peak one to four hours after it’s consumed, but some people who are sensitive to caffeine can feel its effects up to 12 hours later. Be aware that some other beverages and foods also contain caffeine that could keep you up at night. This includes decaf coffee (there is up to 20 mg caffeine in decaf), teas, chocolate, and most sodas. Additionally, some over-the-counter cold and headache remedies are also high in caffeine. Be sure to limit all caffeine sources to 4-6 hours before bedtime, and even longer if you know you are sensitive to caffeine’s effects.


A large late evening meal interferes with sleep as your body is busy digesting. You may also suffer from heartburn or indigestion. Try to eat at least three hours before going to bed.


It’s clear that nutrition DOES have an impact upon sleep and that there’re certain things you need to either consider including in or eliminating from your diet if you’re struggling to sleep! Of course, nutrition is only part of an overall approach to getting a great night’s sleep and, in addition, it’s important that you’re sleeping under the correct bedding and duvets for the time of year, sleeping on the right pillows and, ideally, using a mattress topper!