Thursday 17 September 2009

Insomnia and Nutrition


If you suffer from insomnia, especially long-term insomnia, you will know that there are many contributory factors. Some are more obvious than others – a snoring bedfellow or wakeful child, anyone? Any form of stress is not normally associated with a good night’s sleep. The effects of being regularly awoken by babies or having your sleep patterns interrupted by shift work may still be obvious years later. Obviously it probably isn’t possible to change some of the factors affecting your sleep, but there may be other things you can do.

‘Sleep hygiene’ refers to all the behaviourial and environmental factors which precede sleep and so can interfere with it - in other words, your evening routine and bedroom set-up. It is generally recommended that people get up at the same time each day and go to bed when they are tired, while making sure that their bedroom is not too hot, cold, noisy or brightly lit. Most authorities on sleep advocate keeping the TV out of the bedroom, as you need to associate your bed with sleep not stimulation.

Coffee, alcohol and nicotine are other stimulants which can interfere with sleep, and as such it is worth avoiding them for several hours (at least) before bedtime. Caffeine for example, speeds up the action of the nervous system as well as other major body systems. Within fifteen minutes of a cup of coffee, the level of adrenaline in your blood rises, triggering an increase in heart rate, breathing rate, urinary output and production of stomach acids. In other words caffeine's effects are the reverse of what you want to happen as you go to sleep. Some people are more sensitive than others to the effects of caffeine and need to remember that it is found not only in coffee and tea, but also chocolate and cola drinks.

What can you eat and drink in the evening to help you sleep better? Tryptophan is an amino acid which is used by the body to make sleep-inducing subtances called serotonin and melatonin. So eating foods rich in tryptophan should help us sleep better, right? And it is an amino acid, so we should eat protein, right? Well, it’s not quite that simple…

Tryptophan is the least plentiful amino acid in a normal meat-eating or vegetarian diet. In order to be used to make serotonin it must first get into the brain, across the protective blood-brain barrier. This can be a problem as it wants to enter the brain using the same transporter molecules as several other, more plentiful amino acids. The best way to give tryptophan a helping hand into the brain is actually to eat a meal, snack or drink which is rich in carbohydrates, with just a little tryptophan-containing protein. Foods which are high in tryptophan include dairy, soy, eggs, meat and poultry, as well as whole grains, pulses, hazelnuts, peanuts, sesame and sunflower seeds. So yet again, traditional ideas are largely backed up by science - good bedtime snacks include a malted hot milk drink, wholegrain cereal and milk or a turkey sandwich. Foods containing calcium as well as tryptophan, such as milk or sesame seeds, are helpful as the calcium can also help convert the trypophan to melatonin. In addition, try to choose complex carbohydrates such as brown bread so that your blood sugar is less likely to drop during the night. Low blood sugar can induce a surge of adrenaline, which may wake you up with a start.

It is worth mentioning that tryptophan takes about an hour to reach the brain, so don’t have your snack or drink too close to bedtime. And eating a high fat snack may slow down your digestion, leaving you with a gurgling stomach at bedtime, so easy on the mayonnaise in your sandwich!

My parents always drank a milky coffee at about 10pm – a ritual which fills me with horror, as I personally struggle to sleep if I have had a sniff of a cup of tea after about lunchtime! This is a prime example of how different we all are, and why we need to experiment to figure out what works best for each of us as individuals.

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