A good night’s sleep is extremely important for good health – just as important as healthy eating and regular exercise.
Research continues to indicate that what you eat can play an important role in the quality of your slumber.
Firstly – Why is Sleep So Important?
Good, restful sleep is so important for wellbeing. It’s so important that your body has its own time-keeping clock, known as your circadian rhythm. It’s a 24-hour internal clock that affects your brain, body and hormones. It can keep you alert and awake, but it can also tell your body when it’s time to sleep.
Essentially sleep as an opportunity to reset your entire body – particularly the brain.
Good sleeping patterns (~8 hours each night) can be beneficial to health in various ways; improved brain function (that means better concentration, productivity and memory), improved immunity and even improved athletic performance.
On the other hand, poor sleeping patterns (less than 7 hours each night) have been associated with reduced brain function and decreased immune function (that means a greater risk of developing a nasty cold!), and increased risk of various health conditions (including obesity, type 2 diabetes, depression and heart disease).
How are Sleep and Diet Related?
Science suggests that not only can our sleeping patterns impact the foods we consume, but the foods which we consume (particularly around bedtime) can actually impact our quality of sleep.
Effects of tiredness on appetite
Do you find yourself reaching for more food when you’ve had a poor night’s sleep? This is no coincidence.
Lack of sleep increases the hormone (ghrelin), which makes you feel hungry, while suppressing the hormone (leptin) that makes you feel full. Not only do we tend to reach for those energy rich (often nutrient poor) foods, but our brains actually experience a more rewarding response to those foods, than it would if you were well-rested.
This combination can lead to weight gain which, in turn, increases our risk of sleep apnoea and snoring – two problems that play havoc with a good night’s rest. With adequate sleep however, these hormones find a balance which keeps our appetite in a healthy state.
In addition to this, early research has indicated that lack of sleep may also impact your gut flora. Studies have found that just two days of sleep deprivation can cause subtle changes to the gut flora and increase the abundance of bacteria associated with weight gain, obesity, type 2 diabetes and fat metabolism.
Effects of diet on sleep
The evidence on how our overall diet effects our sleep is less extensive, however some aspects of diet have been associated with particular sleep characteristics.
For example, one study found a Mediterranean style diet in older adults with insomnia was associated with improved sleep quality. Higher intakes of saturated fat and sugar, along with low fibre diets have, on the other hand, been associated with a more restless sleep and overall reduced sleep quality.
This may be linked to gut health as we know a low fibre diet can impact the diversity and number of beneficial microbes living in the gut.
When our diet is lacking in particular nutrients, this can also negatively impact our sleep. For example, deficiencies in magnesium, iron and folate have been associated with a shorter sleep duration, and calcium deficiency has been linked to difficulty falling asleep.
What is becoming more well understood is the various components of foods which work to promote good quality sleep and regulate the body’s sleep cycle. We’ve explored 9 foods that have evidence to suggest their properties can potentially help with a good night’s sleep.
9 Foods for a Good Night’s Sleep
- Almonds: are a great source of melatonin (a hormone that helps regulate our sleep). The magnesium in almonds is also believed to improve sleep quality, by reducing cortisol (stress hormone), which can be counteractive to a good night’s sleep.
- Chamomile Tea: contains an antioxidant (apigenin) which has an effect on your brain which may increase sleepiness. Some studies have even linked chamomile tea consumption to shorter time taken to fall asleep and less night-time wakening.
- Kiwi Fruit: contains serotonin, which is a brain chemical that helps regulate your sleep cycle. It’s also been suggested that the antioxidants in kiwi fruit may have a role in reducing inflammation and resultantly having sleep-promoting effects. One small study found that eating two kiwis an hour before bed helped people fall asleep faster.
- Tart Cherry Juice: tart cherries are a natural source of melatonin, helping to regulate your internal body clock and signalling to your body it’s time to prepare for sleep. One study found that people with insomnia who drank tart cherry juice once in the morning and again at night slept an hour longer on average and experienced better sleep quality, too
- Oily Fish: such as salmon, tuna or mackerel contain both omega-3 fatty acids and vitamin D, which are believed to enhance sleep quality by increasing serotonin (the sleep-promoting chemical). Some evidence has even associated consumption with shorter time to fall asleep, improved sleep quality and a deeper sleep.
- Milk: is believed to have a sleep-promoting effect due to its higher tryptophan and melatonin concentrations. Tryptophan signals an increased production of serotonin, which then works alongside melatonin to regulate your body clock and prepare the body for sleep.
- Greek yoghurt: yoghurt might assist in getting a good nights sleep as it’s a good source of magnesium. It’s also high in protein, which will help keep you satiated.
- Bananas: Bananas help promote sleep because they contain the natural muscle-relaxants magnesium and potassium. Banana’s are also a carbohydrate, which is invovled in making serotonin (the neurotransmitter that helps you feel more relaxed and calm.
- Legumes: legumes are a great source of magnesium, which has been shown to help reduce anxiety and improve sleep in those who might be low in magnesium.
This is not a complete list. There are a huge number of foods, herbs, supplements that might help when it comes to falling asleep.
Try and eat at regular times throughout the day as this is thought to help with sleep habits. Also, try and stop eating at least 2 hours (ideally 3 hours) before bedtime to allow time for your body to properly digest the meal.
Foods & Drinks that Might Negatively Impact Sleep
- Alcohol: while alcohol may help you relax initially, it goes on to disrupt the really beneficial restorative sleep, so it’s best to avoid it before bed. You’re also more likely to wake up in the middle of the night when the alcohol wears off. If you do indulge, stick with one standard serve (e.g. a small glass of wine or a 250ml glass of beer).
- Caffeine: caffeine stimulates our nervous system and helps to keep us awake. This can be helpful in the morning when you might be looking for a pick-me-up. However, consuming caffeine in the afternoon or evening may impact your sleep. We generally advise avoiding high quantities of caffeine after 2pm in the afternoon.
- Drinking too much fluids: avoid drinking too much liquid immediately before bed. While a small mug of milk or chamomile tea may help you doze off, too much will inevitably mean you wake with a full bladder, disturbing your sleep.
The Bottom Line
Sleep is incredibly important and impacts your immunity, appetite, energy levels and brain functioning.
Sleep deprivation can often lead to selecting energy dense, nutrient-poor foods. Selecting foods high in sugar and saturated fat can also negatively impact your sleep quality.
The good news is, there are some specific foods which may even be helpful in promoting a good night’s sleep by helping regulate your body clock and prepare the body for rest.