ADHD (Attention Deficit and Hyperactivity Disorder) - Food for the Brain

About ADHD

Children with ADHD may have three basic problems, they can’t pay attention, they are hyperactive, they act on impulse. It can however be difficult to draw the line between the behaviour of a child that is within the normal limits of high energy, and abnormally active behaviour.

It’s estimated that up to 5 per cent of school-age children in England and Wales have ADHD. That’s around 367,000 children. This means that in a class of 30 children there will be one or two children with ADHD.

Boys seem more likely to have ADHD than girls. In the UK, between three and nine boys are diagnosed with ADHD for every girl who’s diagnosed with it but this may be because boys and girls tend to have different symptoms of ADHD. Inattention is more common among girls while hyperactivity is more common among boys. And a boy who is hyperactive (shouting, running about and getting into trouble) is more noticeable than a girl who is inattentive (daydreaming, forgetful and easily distracted).

Several studies done in recent years estimate that between 30 per cent and 70 per cent of children with ADHD continue to exhibit symptoms in the adult years.

Doctors aren’t sure exactly what goes wrong in ADHD. But they think that the behaviour problems are linked to the way that the front part of the brain works. Studies suggest that this part of the brain works more slowly in children with ADHD than in other children. Children with ADHD may have an imbalance in the neurotransmitters in the front part of the brain. Some doctors believe they don’t have enough of a neurotransmitter called dopamine. Children with ADHD may also lack the neurotransmitter noradrenaline. Without enough dopamine or noradrenaline, the front part of the brain can’t deal with and react to information in the way that it should. This is why some drug treatments for ADHD aim to increase the amount of dopamine or noradrenaline in the brain.Unfortunately, there are no tests that show whether the front part of a child’s brain is working normally. So doctors have to rely on what children, parents and teachers say in order to diagnose ADHD.

To make a diagnosis, doctors usually ask parents and teachers about a child’s behaviour. Your doctor will then compare your child’s behaviour to the symptoms of ADHD put together by psychiatrists. These symptoms are listed in a book called the Diagnostic and Statistical Manual of Mental Disorders (DSM). The DSM says that to be diagnosed with ADHD, your child must have six or more symptoms of not paying attention (inattention) or six or more symptoms of being overactive (hyperactivity) and acting before thinking (impulsivity); these symptoms must have started before your child was 7 years old; your child must have been behaving like this for at least six months; your child’s behaviour must be causing problems in at least two places, such as at home and at school. Your doctor may also want to rule out other medical causes of your child’s symptoms

Conventional treatment options typically involve behaviour therapy and/or medication. The best results we’ve seen in nutrition clinic settings in helping those with ADHD/hyperactivity are achieved by investigating a number of possible avenues. These include looking at the below nutritional factors:

Nutrition and ADHD Hyperactivity: What Works

Balance Blood Sugar

Dietary studies consistently reveal that hyperactive children eat more sugar than other children, and reducing sugar has been found to halve disciplinary actions in young offenders . Other research has confirmed that the problem is not sugar itself but the forms it comes in, the absence of a well-balanced diet overall, and abnormal glucose metabolism. A study of 265 hyperactive children found that more than three-quarters of them displayed abnormal glucose tolerance, – that is, their bodies were less able to handle sugar intake and maintain balanced blood sugar levels.

In any case, when a child is regularly snacking on refined carbohydrates, sweets, chocolate, fizzy drinks, juices and little or no fibre to slow the glucose absorption, the levels of glucose in their blood will seesaw continually and trigger wild fluctuations in their levels of activity, concentration, focus and behaviour. These, of course, are also the symptoms of ADHD.

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

Side effects? If sugar consumption is high and it is withdrawn suddenly, withdrawal symptoms such as headaches and irritability may ensue. Better to make gradual reductions to avoid this, without losing sight of the eventual goal of a no sugar diet.

Contraindications with medication? Diabetes medication should be closely monitored since dosages may need to be lowered.

Key Action:

Cut out sugar and all sources of sugar. Eat only unrefined carbohydrates and ensure these are combined with protein and plenty of fibre to further slow the sugar release. Avoid stimulants, even apparently ‘natural’ ones.

Increase Omega-3 Fat

Omega-3s have a clearly calming effect on many children with hyperactivity and ADHD. And many children with ADHD/hyperactivity have visible symptoms of essential fat deficiency such as excessive thirst, dry skin, eczema and asthma.

It is also interesting that boys, whose requirement for essential fats is much higher than girls’, are also much more likely to have ADHD. Researchers have theorised that ADHD children may be deficient in essential fats not just because their dietary intake from foods such as seeds and nuts is inadequate (though this is not uncommon), but also because their need is higher, their absorption is poor, or they are unable to convert these fats well into EPA and DHA, and from DHA into prostaglandins, which are also important for brain function4.

So it’s of interest that the conversion of essential fats can be inhibited by most of the foods that cause symptoms in children with ADHD, such as wheat, dairy and foods containing salicylates. (See below for more on salicylates) This conversion is also hindered by deficiencies of the various vitamins and minerals that help the enzymes driving these conversions – vitamins B3 (niacin), B6, C, biotin, zinc and magnesium. Zinc deficiency is common in children with ADHD.

Research carried out at Purdue University in the US confirmed that children with ADHD have an inadequate intake of the nutrients required for the conversion of essential fats into prostaglandins, and have lower levels of EPA, DHA, and AA than children without ADHD. Supplementation with all these omega-3 essential fats, pre-converted, along with the omega-6 essential fat GLA, reduced ADHD symptoms such as anxiety, attention difficulties and general behaviour problems6,7,8.

Research at Oxford University using omega 3 and omega 6 fish oil supplements has proven the value of these essential fats in a double-blind trial involving 41 children aged 8 to 12 years who had ADHD symptoms and specific learning difficulties. Those children receiving extra essential fats in supplements were both behaving and learning better within 12 weeks.

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

Side effects? Rarely causes loose stools in sensitive individuals if you start on too high a dose.

Contraindications with medication? Essential fats may have a ‘blood-thinning’ effect and should not be mixed with ‘blood thinning’ medication.

Key Action:

Eat fish at least twice a week, seeds on most days and supplementing omega 3 fish oils. Look for a supplement that contains EPA, DHA and GLA.

The best fish for EPA, the type of omega 3 fat that’s been most thoroughly researched are: mackerel (1,400mg per 100g/3oz), herring/kipper (1,000mg), sardines (1,000mg), fresh (not tinned) tuna (900mg), anchovy (900mg), salmon(800mg), trout (500mg). Tuna, being high in mercury is best eaten not more than twice a month.

The best seeds are flax seeds and pumpkin seeds. Flax seeds are so small they are best ground and sprinkled on cereal. Alternatively, use flax seed oil, for example in salad dressings. While technically providing omega 3 only about 5% of the type of omega 3 (alpha linolenic acid) in these seeds is converted in your body into EPA.


Increase Vitamins and Minerals

Although it is unlikely, on the basis of the studies to date, that ADHD is purely a deficiency disease, most children with this diagnosis are deficient in certain key nutrients, and do respond very well.

Zinc and magnesium are the most commonly deficient nutrients in people with ADHD. In fact, symptoms of deficiency in these minerals are very similar to the symptoms of ADHD. Low levels of magnesium, for instance, can cause excessive fidgeting, anxious restlessness, insomnia, coordination problems and learning difficulties (if accompanied by a normal IQ).

Polish researchers studying 116 children with ADHD for their levels of magnesium found that 95 per cent of them were deficient in it – a much higher percentage than that among healthy children. The team also noted a correlation between levels of magnesium and severity of symptoms. Supplementing 200mg of magnesium for six months significantly reduced hyperactivity in the children with ADHD, but behaviour in the control group, who received no magnesium, worsened10.

Dr Neil Ward of the University of Surrey has come up with a finding that could explain the link between ADHD and such deficiencies. In a study of 530 hyperactive children, Ward found that compared to children without ADHD, a significantly higher percentage of children with the condition had had several courses of antibiotics in early childhood11. Further investigations revealed that children who had had three or more such courses before the age of three tested for significantly lower levels of zinc, calcium, chromium and selenium12. This is probably because antibiotics have a disruptive effect on beneficial gut flora and consequently on overall digestive health, impairing absorption.

Where’s the evidence? Search our evidence database and enter ‘vitamins’, ‘minerals’ or ‘nutrients’ into the search field for a summary of studies that demonstrate the effect of vitamins and minerals on behaviour.

Side effects? None reported.

Contraindications with medication? None reported.

Key Action:

A diet rich in whole foods such as fresh fruit and vegetables, seeds, nuts and whole grains is naturally higher in vitamins and minerals. Avoid processed foods that have had many nutrients removed.

Consider Allergies

Of all the avenues so far explored, the link between hyperactivity and food sensitivity is the most established and worthy of pursuit in any child showing signs of ADHD. Food allergies can be of two types: Type 1 in the classical, severe and immediate allergy most commonly associated with peanuts and shellfish. This allergy involves an antibody called IgE and most people discover if they have this type of allergy early in life since the reaction is so immediate and severe. The second type, which we will call Type 2 involves the IgG antibody which works in quite a different way. Symptoms of these allergies can be many and varied and may take many hours to appear. These allergies often go undetected for this reason.

A study by Dr Joseph Bellanti of Georgetown University in Washington DC found that hyperactive children are seven times more likely to have food allergies than other children. According to his research, 56 per cent of hyperactive children aged 7 to 10 tested positive for food allergies, compared to less than 8 per cent of ‘normal’ children. Children with ADHD/hyperactivity may also have a sensitivity to additives and preservatives. A separate investigation by the Hyperactive Children’s Support Group found that 89 per cent of children with ADHD reacted to food colourings, 72 per cent to flavourings, 60 per cent to MSG, 45 per cent to all synthetic additives, 50 per cent to cow’s milk, 60 per cent to chocolate and 40 per cent to oranges13.

Other substances often found to induce behavioural changes are wheat, corn, yeast, soya, peanuts and eggs14. Symptoms strongly linked to allergy include nasal problems and excessive mucus, ear infections, facial swelling and discolouration around the eyes, tonsillitis, digestive problems, bad breath, eczema, asthma, headaches and bedwetting.

A considerable number of hyperactive children may benefit from eliminating foods that contain artificial colours, flavours and preservatives; processed and manufactured foods; and ‘culprit’ foods identified by either an exclusion diet or blood test15. Some parents have also reported success with the Feingold diet, removing not only all artificial additives but also foods that naturally contain compounds called salicylates.

Researchers at the University of Sydney in Australia found that three-quarters of 86 children with ADHD reacted adversely to foods containing salicylates16. These include prunes, raisins, raspberries, almonds, apricots, canned cherries, blackcurrants, oranges, strawberries, grapes, tomato sauce, plums, cucumbers and Granny Smith apples. As the list of foods containing salicylates is very long and contains many otherwise nutritious foods, cutting them all out should be considered only as a secondary course of action, and must be carefully planned and monitored by a nutritional therapist.

Understanding how a low-salicylate diet helps hyperactive children does offer a useful alternative to such a drastic course of action. Salicylates inhibit the conversion and utilisation of essential fats, which are often low in hyperactive children. So instead of avoiding salicylates, it may help to simply increase the supply of essential fats.

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

Side effects? A sudden and complete removal of a food from the diet may lead to an initial worsening of symptoms and cravings for that food, as well as increase risk of nutritional deficiency. Any major changes in diet should be supervised by a suitably qualified registered nutrition practitioner and doctor.

Contraindications with medication? None reported.


1. R. J. Prinz et al., ‘Dietary correlates of hyperactive behaviour in children, J Consulting Clin Psychol, Vol 48, 1980, pp. 760-69

2. S. J. Schoenthaler et al., ‘The effect of randomised vitamin-mineral supplementation on violent and non-violent antisocial behaviour among incarcerated juveniles’, J Nut Env Med, 1997

3. L. Langseth and J. Dowd, ‘Glucose tolerance and hyperkinesis’, Fd Cosmet Toxicol, Vol 16, 1978, p.129

4. I. Colquhon and S. Bunday, ‘A lack of essential fats as a possible cause of hyperactivity in children’, Medical Hypotheses, Vol 7, 1981, pp. 673-9

5. L. J. Stevens et al., ‘Essential fat metabolism in boys with attention-deficit hyperactivity disorder’, Am J Clin Nutr, Vol 65, 1995, pp. 761-8

6. J. R. Burgess, ADHD: observational and interventional studies, NIH workshop on omega-3 EFAs in psychiatric disorder, National Institutes of Health, Bethesda, Maryland, 1998

7. A. J. Richardson et al., Treatment with highly unsaturated fatty acids can reduce ADHD symptoms in children with specific learning difficulties: a randomised controlled trial, paper given at British Dyslexia Association International Conference, University of York, April 2001

8. A. Richardson and B. Puri, ‘A randomized double-blind, placebo-controlled study of the effects of supplementation with highly unsaturated fatty acids on ADHD-related symptoms in children with specific learning difficulties’, Prog Neuropsychopharmacol Biol Psychiatry, Vol 26(2), 2002, pp. 233-9

9. A. Richardson and B. Puri, ‘A randomized double-blind, placebo-controlled study of the effects of supplementation with highly unsaturated fatty acids on ADHD, Prog Neuropsychopharmacol Biol Psychiatry, 2002

10. B. Starobrat-Hermelin and T. Kozielec, ‘The effects of magnesium physiological supplementation on hyperactivity in children with attention deficit hyperactivity disorder (ADHD): Positive response to magnesium oral loading test’, Magnes Res, Vol 10(2), 1997, pp. 149-56

11. N. I. Ward, ‘Assessment of clinical factors in relation to child hyperactivity’, J Nutr Environ Med, Vol 7, 1997, pp. 333-342

12. N. I. Ward, ‘Hyperactivity and a previous history of antibiotic usage’, Nutrition Practitioner, Vol 3(3), 2001, p. 12

13. B. O’Reilly, Hyperactive Children’s Support Group Conference, London, June 2001

14. M. D. Boris and F. S. Mandel, ‘Foods and additives are common causes of the attention deficit hyperactive disorder in children’ Ann Allergy, Vol. 72 (1994), pp. 462-468

15. R. J. Theil, ‘Nutrition based interventions for ADD and ADHD’, Townsend Letter for Doctors & Patients, April 2000, pp. 93-5

16. A. R. Swain et al., ‘Salicylates, oligoantigenic diet and behaviour’, Lancet, Vol. 2(8445), 1985, pp. 41-2