THE SCIENCE OF SLEEP
All cultures around the world have traditions about which foods promote sleep. Foods such as milk, chamomile, kiwi fruit and tart cherries have all been said to work wonders. Given how much the food we eat affects us, it is not surprising that our diet plays such a big role in our quality of sleep. What we eat affects our organ function, immune system, hormone production and brain function.
A really important hormone that controls our sleep patterns is melatonin. It is produced in the brain and the amount you produce and how efficiently our brain uses it is affected by our diet. One of the biggest influences on our melatonin levels appears to be our intake of a type of protein called tryptophan, an essential amino acid and the building blocks of proteins. Our bodies cannot make it, it can only be sourced through diet.
Other nutrients that appear to be helpful for sleep include B vitamins and magnesium. This is because they help tryptophan to be more available in the body. If your diet is lacking tryptophan, B vitamins or magnesium it is very likely that your melatonin production and secretion will be affected and your sleep quality will be poorer.
EAT TO SLEEP
Overly restrictive diets or diets that put you at risk of nutrient deficiencies can affect your sleep. But increasing your intake of foods rich in specific nutrients may well help to promote better sleep quality and duration.
Dairy foods can be great at helping you sleep. Not only is dairy an excellent source of tryptophan, but it also contains magnesium and B vitamins which help to promote the activity and availability of tryptophan. Nuts, like dairy, also contain all the nutrients known to promote increased melatonin production and support its release.
Fish is a great source of tryptophan and B vitamins. Fish with bones, such as sardines, will also provide magnesium. Including fish in your diet regularly may help to promote healthy melatonin production. Pulses, beans and lentils also contain high amounts of tryptophan and B vitamins. Adding some tofu or paneer to a vegetable stew or curry can also help to increase your likelihood of a great night’s sleep. You could also add in soya – another good source of tryptophan – to optimise your sleep potential.
If you’re still struggling to sleep, you may benefit from lean meat. It contains all the essential ingredients for a good night’s sleep.
For the ideal bed time snack, try a glass of semiskimmed or skimmed milk, a small banana or a few nuts – all of which can help improve sleep and your willpower the next day. It takes around an hour for the tryptophan in foods to reach the brain, so don’t wait until just before bedtime to have a snack. It’s advisable to have a balanced diet high in tryptophan to optimise your chances of a good night’s sleep.
Sophie Medlin, Lecturer in Nutrition and Dietetics, King’s College London