Insomnia - Food for the Brain

About Insomnia

Insomnia can be a significant cause of stress, mood problems and irritability, not to mention daytime sleepiness and feelings of tiredness. Lack of sleep can also lower your immune response and if it’s chronic it may even raise your risk of dementia.

Not surprisingly, there are a number of causes of poor sleep. The key factors that seem to affect most people who seek help at the Brain Bio Centre are poor blood sugar control, excess caffeine, lack of the necessary neurotransmitters and hormones, and lack of some key nutrients with magnesium being top of the list.

Nutrition and Insomnia; what works

Blood sugar balance

If you have blood sugar levels which fluctuate wildly throughout the day and night, this can affect your sleep. Excessive sugar in your blood can have you feeling wide awake, whereas if your blood sugar is low, your body’s response is to release cortisol, a naturally-occurring hormone whose function is to release stored sugar into the bloodstream. Cortisol has a natural cycle in the body and low levels are required prior to sleep.

Also, if your blood sugar levels are low, you will probably feel hungry which may keep you awake, and you may also feel irritable which won’t help either.

Fluctuating blood sugar levels are generally a result of consuming too many high GL (glycaemic load) carbohydrates which release their sugar quickly. The body’s response to this is an excessive release of insulin to escort sugar into the body’s cells which can lead to low blood sugar levels. Low blood sugar levels cause cravings for carbohydrates or cortisol release and so the cycle continues.

Where’s the evidence? Search our evidence database and enter ‘sugar’ and ‘sleep’ into the search field for a summary of studies that demonstrate the effect of blood sugar imbalance on sleep.

Side effects? None

Contraindications with medication? Diabetes medication should be closely monitored since dosages may need to be lowered if sugar intake is reduced significantly.

Key Action

Eat a diet that will stabilise your blood sugar (known as the Low GL diet): this means eating low GL carbohydrates, as well as combining your low GL carbohydrates with protein in a ratio of 1:1.

Eat at regular intervals: including snacks that include low GL carbohydrate and protein such as fresh fruit with a handful of nuts, oatcakes with humous or celery and cottage cheese.

Sweet Foods: only eat sweet foods as a very occasional treat and only after a meal or healthy snack

Amino Acids for Neurotransmitters and Hormones

There is a complex interplay in the body between various neurotransmitters and hormones which affect sleep.

The key sleep hormone is called melatonin. It is released from the pineal gland during the late evening (stimulated by decreasing light levels); it peaks at around 3 or 4am, before dropping off sharply between around 6 and 8am, in part as a response to increasing light levels. Melatonin is an almost identical molecule to serotonin (our key mood neurotransmitter), from which it is made, and both are made from 5-HTP, itself derived from the amino acid tryptophan which is present in most protein foods. The conversion of amino acids into neurotransmitters and hormones requires nutrient co-factors, in particular the B vitamins, so a lack of these may also be responsible for low melatonin levels. The amino acid L-tryptophan is found in protein rich food, whereas 5-HTP can only be taken in supplement form. Melatonin is available on prescription in the UK, but can be purchased in the US.

Another key neurotransmitter is GABA – it is the body’s major relaxing neurotransmitter. In fact alcohol and benzodiazepine medication (eg valium) have a similar action to GABA which is why our initial response to these substances is a feeling of relaxation. Of course alcohol and benzodiazepines are not the answer to a sleep problem. Alcohol may help us get to sleep but for most people it will cause non-restorative sleep, and early waking. And both of these substances are addictive drugs with side-effects. There is an amino acid called Taurine which also provides the GABA effect, but because it’s a naturally-occurring amino acid that is found in the diet, it has a gently relaxing effect and no addictive properties or side-effects. The herb valerian also promotes the GABA effect.

Where’s the evidence? Search our evidence database and enter ‘amino acids’ and ‘sleep’ into the search field for a summary of studies that demonstrate the effect of amino acids on sleep.

Side effects? Drowsiness. In our experience about 5% of people who take 5-HTP or L-tryptophan experience side-effects such as irritability and agitation – if you experience any unpleasant side-effects, discontinue the supplementation immediately.

Contraindications with medication? Supplementing 5-HTP or L-tryptophan is contraindicated with antidepressant medication. Valerian may be contraindicated with medication – always check with your prescribing doctor or pharmacist before taking herbs alongside medication.

Key Action:

Eat foods which are high in tryptophan, like chicken, cheese, tuna, tofu, eggs, nuts, seeds and milk. Tryptophan requires the presence of insulin to escort it into the brain where it can be converted into serotonin, so include some carbohydrate (but keep it low GL) so you don’t disrupt blood sugar (see above).

If you are not taking antidepressant medication you could supplement either 500mg of tryptophan or 100 to 200mg of 5-HTP half an hour before you go to bed. In our experience about 5% of people who take these amino acids experience side-effects such as irritability and agitation – if you experience any unpleasant side-effects, discontinue the supplementation immediately.

Taurine is found primarily in meat and seafood, so you are likely to be most at need if you are a vegetarian. Try 1,000mg of taurine at night, taken away from food.


Magnesium is known as ‘nature’s relaxant’. Its role in the body is to counteract the contracting effect of calcium. In the modern diet, most people take in plenty of dietary from dairy products, but it seems that magnesium intake is dropping. Magnesium is found in highest amounts in green leafy vegetables and pumpkin seeds. Of course, like any mineral, the level of magnesium found in the plant depends on it being present in the soil in which the plant is grown at adequate levels, and with modern farming methods, this may not always be the case.

Where’s the evidence? Search our evidence database and enter ‘magnesium and ‘sleep into the search field for a summary of studies that demonstrate the effect of magnesium on sleep.

Side effects? Increased magnesium intake may reduce anxiety, improve constipation, relieve menstrual cramps, reduce headaches and calm hyperactivity.

Contraindications with medication? Magnesium may lower blood pressure, so if you are taking blood pressure medication, you should keep a close watch on your blood pressure and consult your doctor if it drops as your medication may need to be reduced.

Key Action:

Increase your magnesium intake through increased intake of green leafy vegetables (eg spinach, kale, cabbage, spring greens etc) and pumpkin seeds. You can also supplement 200-400mg of magnesium daily.


For most people the purpose of drinking caffeine is for its stimulating properties, so its no surprise that caffeine from coffee, tea or energy drinks is a cause of insomnia. Caffeine has a variety of biochemical actions including increasing levels of stress and motivation hormones (catecholamines and cortisol) and suppressing melatonin production for up to ten hours. What many people don’t realise, however, is that we are very individual in terms of our sensitivity to caffeine and while some people seem to be able to drink a double-espresso after dinner and apparently sleep well, the more sensitive amongst us will suffer with poor sleep from just a single cup of tea in the morning.

Where’s the evidence? Search our evidence database and enter ‘caffeine and ‘sleep into the search field for a summary of studies that demonstrate the effect of caffeine on sleep.

Side effects? If caffeine consumption is high and it is withdrawn suddenly, withdrawal symptoms such as headaches and irritability may ensue. It’s generally better to make gradual reductions to avoid this.

Contraindications with medication? None known

Key Action:

Cut out caffeine or reduce significantly. If your consumption is high, make the reduction gradually to avoid withdrawal symptoms. Remember that even a small amount of caffeine early in the day can affect sleep for some people. Instead, drink herbal teas or naturally caffeine free teas such as Roibos (redbush). You could also drink the occasional glass of tart cherry juice – those who drank two glasses of tart cherry juice versus placebo had increased melatonin levels, sleep duration and sleep quality, according to a recent study.

Sleep hygiene

Sleep hygiene relates to our sleeping environment and has nothing to do with cleanliness! Essentially, poor sleep hygiene includes using the bedroom for things other than sleeping (for example: work, video games, watching television, using the computer), or sleeping in a room where there is too much light or noise.

Where’s the evidence? Search our evidence database and enter ‘sleep hygiene’ and ‘sleep’ into the search field for a summary of studies that demonstrate the effect of poor sleep hygiene on sleep.

Side effects? None

Contraindications with medication? None

Key Action:

Get rid off computers and other electronics from the bedroom. Ensure that your bedroom is dark and quiet. Relax and wind-down before bed, perhaps with a bath, meditation, relaxation exercises, music, herbal teas such as chamomile or valerian, so that by the time you get into bed you are already in a relaxed state. If you have things on your mind, write them down so you can forget about them until the morning.


T. C. Birdsall, ‘5-Hydroxytryptophan: a clinically-effective serotonin, Alternative Medicine Review, 1998;3(4):271-80