ADHD diet

views updated

ADHD diet

Research and general acceptance

Resources

Definition

Attention deficit hyperactivity disorder (ADHD) is defined as the combination of inattentive, hyperactive and impulsive behavior which are severe, developmentally inappropriate, and impair function at home and in school. Common features include mood swings, anxiety, impulsivity, hostility, poor concentration and sleeping disorders, along with physical complaints such as headaches, migraines, and stomach upsets. ADHD individuals are also more likely to have been of low birth weight and to have allergies or auto-immune problems. Proportionally more males than females are affected, with inattention tending to be a more female trait and hyperactivity more common in males.

ADHD does persist into adulthood, although symptoms tend to diminish with time, but the main focus relates to the problems of children with ADHD. Growing children are especially vulnerable to nutritional and environmental factors that influence brain development and function, which can have either a negative or positive impact. The symptoms of this difficult condition can also significantly compromise their education, making them challenging to teach and consequently having a deleterious effect on their

Possible causes of ADHD-like behavior

A sudden change in the child’s life—the death of a parent or grandparent; parents’ divorce; a parent’s job loss
Undetected seizures, such as in petit mal or temporal lobe seizures
A middle ear infection that causes intermittent hearing problems
Vision problems
Medical disorders that may affect brain functioning
Underachievement caused by learning disability
Anxiety or depression

source: National Institute of Mental Health, National Institutes of Health, U.S. Department of Health and Human Services.

Behaviors associated with ADHD can be caused by other factors. It is best to consult a medical professional to rule out these possibilities. (Illustration byGGS Information Services/ Thomson Gale.).

life-potential. The daily challenges of living with ADHD place a huge strain on families and reduces overall quality of life for all involved.

Origins

Back in 1981, Colquhoun and Bunday undertook a comprehensive survey of children with ADHD and discovered that many showed physical signs of essential fatty acid (EFA) deficiency, including excessive thirst, polyuria, dry hair and skin. These authors were the first to propose that fatty acid deficiency may be a factor in ADHD, and their ground-breaking work prompted more research studies and clinical trials designed to increase understanding of those nutritional factors involved in ADHD.

It has now been proposed that many developmental and psychiatric conditions, including ADHD along with dyslexia, dyspraxia, autism, depression, and schizophrenia, may involve deficiencies of certain long-chained fats , especially eicosapentaenoic acid ( EPA) and docosahexaenoic acid (DHA). Both iron deficiency and zinc deficiency have also been associated with the development of ADHD.

Description

Dietary Fats

Fats have a fundamental structural and functional role in the brain and central nervous system (CNS) and are a key factor in the development ADHD. The two fats that are thought to be especially important are EPA and DHA, not only because of their role in the brain and body but because of the relative lack of them in many people’s diets. EPA is the precursor of a complex group of substances, called eicosanoids, which perform numerous regulatory functions in the brain and body. DHA is a major ‘building block’ of brain and neuronal membranes and as such has a profound influence on cell signalling. Both EPA and DHA are omega-3 fats and can be made from the omega-3 essential fatty acid, alpha linolenic acid (ALA). However, this conversion process can be problematic as genetic and environmental factors, including diet, can cause great variation in an individual’s constitutional ability to convert ALA into EPA and DHA. Dietary factors known to adversely affect this conversion include low intakes of ALA, high intakes of omega-6 fats, saturated fat, hydrogenated fat and alcohol, in addition to vitamin and mineral deficiencies, testosterone and stress hormones. Unfortunately, many dietary surveys have revealed that a typical modern-day diet is rich in omega-6 fats, saturated fats and hydrogenated fats and often low in omega-3 fats and micronutrients. ADHD children are often found to be deficient in iron and zinc and the fact that more boys than girls tend to be affected may be partly explained by the negative effect of testosterone on this conversion process.

In order to avoid a functional deficiency of these important fats, the diet should have a smaller ratio of the omega-6 essential fat, linoleic acid (LA) to omega-3 essential fat (ALA), at an ideal ratio of no more than 5:1, as well as adequate amounts of pre-formed EPA and DHA. The richest dietary sources of LA are certain vegetable and seed oils, including sunflower, safflower, soya, palm, peanut and sesame, all of which should be eaten in good amounts along with oils that are rich in ALA such as rapeseed (canola), flaxseed (linseed) and walnut oil. Olive oil is also recommended, despite having quite a low ALA content, as it is rich in beneficial monounsaturated fats. Looking at types of spreading fat available, many margarines have been specifically formulated to be rich in ALA, although some brands still contain harmful hydrogenated fats, but it is worth remembering that butter actually has a low LA content and when mixed with equal quantities of rapeseed or olive oil, the saturated fat content is much reduced. Other sources of ALA include green, leafy vegetables such as rocket, watercress and spinach as well as fresh green herbs, such as basil, coriander, mint and parsley. Consequently, the food products of animals allowed to graze on open pasture will also be rich in ALA and so organic, free-range and outdoor-reared meat, milk and eggs are the best choice.

When it comes to sources of EPA and DHA, fish and seafood are the best sources with oily fish , such as salmon, trout, mackerel, sardines, herring and anchovies, being especially rich. Fresh tuna is classed as an

Autism— Autism, or autistic spectrum disorder (ASD), is a serious developmental disorder, characterized by profound deficits in language, communication, socialisation and resistance to learning.

Auto-immunity— A response, involving the immune system, that results in a person’s own tissues being attacked.

Benzoic Acid— A type of preservative used in processed foods known to cause food sensitivity in some individuals when consumed in the diet.

Carnitine— This is a naturally occurring substance, needed for the oxidation of fatty acids, a deficiency of which is known to have major adverse effects on the CNS.

Dietitian— A Healthcare Professional, qualified to degree or post-graduate level, who advises individuals on diet and nutrition as part of a treatment strategy for particular medical conditions or for disease prevention.

Dyslexia— An inherent dysfunction affecting the language centres of the brain which results in difficulties with reading and writing.

Dyspraxia— A developmental disorder that affects co-ordination and movement.

Elimination Diet— A diet consisting of a limited range of foods, classed as low risk in terms of causing food sensitivity or allergy.

Essential Fatty Acid— A type of fat that is necessary for the normal function of the brain and body and that the body is unable to produce itself, making them ’essential’ to be taken through the diet and / or supplements.

Ferritin— Iron is stored in the body, mainly in the liver, spleen and bone marrow, as ferritin.

Functional Deficiency— The depleted state of a particular nutrient that precipitates compromised function within the brain or body.

Hydrogenated Fats— A type of fat made by the process of hydrogenation, which turns liquid oils into solid fat. Bio-hydrogenation occurs in ruminant animals (eg. cows) and so small amounts of hydrogenated fats are found in butter, dairy foods and meat but these are accepted as being harmless. The commercial hydrogenation of oils produces large quantities of hydrogenated fats and have been implicated in the development of coronary heart disease and impaired cell signalling in the brain.

Lipid Peroxidation— This refers to the chemical breakdown of fats.

Neurotoxic— A substance that has a specific toxic effect on the nervous system.

Oxidative Injury— Damage that occurs to the cells and tissues of the brain and body by highly reactive substances known as free radicals.

Polyuria— An excessive production of urine.

Sodium Benzoate— A type of preservative used in processed foods known to cause food sensitivity in some individuals when consumed in the diet.

Sodium Metabisulphite— A type of sulphite preservative used in processed foods known to cause food sensitivity in some individuals when consumed in the diet.

Sulphites— A type of preservative used in processed foods known to cause food sensitivity in some individuals when consumed in the diet.

Sulphur Dioxide— A type of preservative used in processed foods known to cause food sensitivity in some individuals when consumed in the diet.

Vanillin— A synthetic version of vanilla flavoring.

oily fish but the canning process causes a significant loss of fatty acids so tinned tuna has an EPA and DHA content comparable to white fish, such as cod, haddock and plaice. Certain varieties of fish are more likely to contain large amounts of pollutants such as mercury and lead which are known to be neurotoxic and so it is prudent for people with ADHD, and all children under 16 years of age, to avoid eating shark, marlin and swordfish. DHA can also be found in liver and egg yolks and so these foods should be incorpo rated into the diet regularly, unless you are taking a nutritional supplement that contains vitamin A in which case you should not eat liver or foods containing liver such as pâté.

A general recommendation of a combined daily dose of 500 mg EPA and DHA is needed to avoid functional deficiency of these important fats, although individuals with ADHD may have an even higher requirement. This weekly total of 3,500 mg is the equivalent of ~3 portions of salmon every week. In the UK, the recommended amount per week for girls and women of childbearing age is two and for boys, men, and women past childbearing age is four. The relative amounts of EPA and DHA does vary greatly between varieties of fish , with mackerel providing 2700 mg per average portion and haddock providing a much lower 170 mg for a medium sized fillet. For many people this variability in EPA and DHA intake is unlikely to have significant consequences as long as fish is regularly consumed , but for individuals with ADHD it may compromise brain function. For this reason pure fish oil supplements that provide a daily standard dose of EPA and DHA are useful in addition to a diet containing fish and seafood. Increasing evidence from well designed clinical trials have indeed shown that supplementation with EPA and DHA alleviate ADHD-related symptoms in some children. These supplements also have the advantage of being relatively safe and offering general health benefits, specifically in terms of cardiovascular protection. Although pure fish oil supplements may be beneficial in some individuals with ADHD it is important to note that more research needs to be done to fully establish the durability of any treatment effects as well as optimal dosages and formulations.

Dietary Antioxidants

If intakes of long-chained polyunsaturated fats (PUFAs), such as EPA and DHA, increase then so does the risk of lipid peroxidation by the action of harmful free radicals, smoking, and pollutants, etc.; substances produced in the body by normal processes such as breathing and metabolism. PUFAs are highly susceptible to attack from these reactive substances and need the protection of antioxidants to avoid getting damaged and thus affecting the structure of the lipid membranes of the brain and CNS. When free radical production is insufficiently countered by antioxidants the resultant damage to the brain and body is termed ’oxidative injury’.

Dietary antioxidants include nutrients such as vitamin E and selenium as well as biologically active substances such as flavonols, anthocyanins and carotenoids, found in highly colored fruits and vegetables, nuts, tea and red wine. Vitamin E is naturally found in PUFA-rich foods like oils and nuts whilst selenium is found in fish, seafood, liver, egg, brazil nuts, mushrooms and lentils. Eating the recommended daily minimum of 5 portions of fruit and / or vegetables should provide adequate amounts of complementary dietary antioxidants, especially if a wide range of colors and varieties are chosen.

Dietary Iron

Iron deficiency has been associated with ADHD in children and tends to be worse even when compared with iron-deficient non-ADHD controls. Lower serum ferritin levels correlate with more severe ADHD symptoms and greater cognitive deficits.

Dietary sources of iron include red meat, fortified breakfast cereals, pulses and dried apricots and these foods should feature regularly in the ADHD diet. Additional supplementary iron may be required in cases of proven iron deficiency.

Dietary Zinc

Zinc has a range of important functions in the body, including the metabolism of neurotransmitters and fatty acids, with zinc deficiency possibly having an effect on the development of ADHD. Children with ADHD who have been treated with supplementary zinc have exhibited reduced hyperactive, impulsive and impaired-socialisation symptoms.

Foods known to be rich in zinc include seafood, liver, pine nuts, cashew nuts and wholegrain cereals and so should be eaten regularly to help avoid deficiency.

Synthetic Food Additives

Certain synthetic food colorings, flavorings and preservatives, have been linked to increase hyperactivity in some ADHD and non-ADHD children. Many of these additives are unnecessary and are frequently used to sell poor-quality foods, that are often marketed specifically at children.

The following additives have been implicated in adverse reactions:

E102
E104
107
E110
E122
E123
E124
128
133
E142
E150
E151
E154
E155
E180
E220
E221
E222
E223
E224
E226
E227
E228
benzoic acid
sodium benzoate
sodium metabisulphite
sulphur dioxide
vanillin

Function

The ADHD diet works by providing the right type and amount of fats needed for the brain and CNS as well as providing sufficient amounts of iron and zinc to avoid nutritional deficiencies that are known to be associated with worsening ADHD symptoms. Nutritional supplements should be taken upon the advice of a Doctor or Dietitian and taken in addition to a healthy, balanced diet. Dietary provision of antioxidants are needed to protect the long-chained fats from breakdown which would affect brain structure and compromise signalling within the brain and CNS. Finally, the ADHD diet excludes those synthetic food additives that have been identified as having the potential to adversely affect the behavior of ADHD, and non-ADHD children alike.

Benefits

The key benefit of the ADHD diet is that it provides the correct types of foods needed to support the nutritional requirements of both the brain and body. It provides the nutrients needed to sustain good growth and development in children, as well as general health promotion for all, whilst excluding potential antagonistic additives. The diet supports other treatment strategies, including stimulant medication, and so helps to improve the quality of life and educational possibilities of those individuals affected.

Precautions

Detailed, personalized advice should always be sought from a suitably qualified dietitian, especially when dealing with children. Any nutritional supplements should always be taken according to the manufacturers instructions and at the prescribed dosage. If

QUESTIONS TO ASK YOUR DOCTOR

Which nutritional supplements are recommended for ADHD?
What are the best food choices for ADH D?
Which food additives should be avoided?
What are the vegetarian sources of omega 3 fats?

other medication is being taken then advice should be sought from a doctor.

Risks

It has been reported that fish oil supplements when taken along side stimulant medication can exacerbate hyperactive behavior in some ADHD individuals. In these circumstances, the supplement should continue to be taken and the dosage of the medication be altered accordingly, under the supervision of a Doctor.

Fish oil supplements can also reduce blood clotting times and so should not be used if anti-coagulant medication is already being taken.

There is no risk attached to the ADHD diet in terms of foods chosen and the diet can be safely followed by ADHD and non-ADHD individuals alike.

Research and general acceptance

Among the specialists working in this particular field, there is a general consensus that ADHD is a disorder that involves a functional deficiency of the long-chained fats, EPA and DHA that frequently coexists with zinc and iron deficiencies. Among the wider community there remains a great deal of scepticism about ADHD and the role that diet has in its development or management.

In terms of supplementation, insufficient data is available to formulate a standardized treatment strategy and it is unclear whether the micronutrient deficiencies are a cause of, or secondary to, ADHD. Other intervention studies have looked in to carnitine supplementation and elimination diets but their findings remain inconclusive.

It is certainly well accepted that there is still very much more to be learned about ADHD and how nutrients interact to either exacerbate or improve ADHD-related symptoms. More research is planned and hopefully more useful findings will help improve the life of all those affected by this debilitating condition.

Resources

BOOKS

Richardson, Alex. They Are What You Feed Them Harper Thorsons 2006

Simopoulos, Artemis and Jo Robinson. The Omega Diet Harper Collins Publishers 1999

Stevens, Laura. 12 Effective Ways to Help Your ADD / ADHD Child Penguin 2000

Stordy, Jacqueline and Malcolm Nicholl. The LCP Solution Macmillan 2002.

PERIODICALS

Akhondzadeh et al. “Zinc sulphate as an adjunct to methylphenidate for the treatment of attention deficit hyperactivity disorder in children: A double-blind and randomised trial” Bio Med Central Psychiatry 2004 4:9.

Antalis et al. “Omega 3 fatty acid status in attention-deficit/ hyperactivity disorder” Prostaglandins Leukotrienes and Essential Fatty Acids 2006 75 (4-5) p299-308.

Bateman et al. “The effects of a double-blind, placebo-controlled, artificial food colourings and benzoate preservative challenge on hyperactivity in a general population sample of pre-school children” Archives of Disease in Childhood 2004 89 p506-511.

Bilici et al. “Double-blind, placebo-controlled study of zinc sulfate in the treatment of attention deficit hyperactivity disorder” Progress in Neuropsychopharmacology and Biological Psychiatry 200428 (1) p181-190.

Bourre. “Effects of nutrients (in food) on the structure and function of the nervous system: update on dietary requirements for brain. Part 1: micronutrients” Journal of Nutrition, Health and Ageing 200610 (5) p377-385.

Bourre. “Effects of nutrients (in food) on the structure and function of the nervous system: update on dietary requirements for brain. Part 2: macronutrients” Journal of Nutrition, Health and Ageing 200610 (5) p386-399.

Brookes et al. “Association of fatty acid desaturase genes with attention deficit/hyperactivity disorder” Biological Psychiatry 2006 epub ahead ofprint.

Colquhoun & Bunday. “A lack of essential fatty acids as a possible cause of hyperactivity in children.” Medical Hypotheses 19817 (5) p673-679.

Galler et al. “Behavioural effects of childhood malnutrition” American Journal of Psychiatry 2005 162 p1760-1761.

Georgieff. “Nutrition and the developing brain: nutrient priorities and measurement” American Journal of Clinical Nutrition 2007 85 (2) supp p614-620.

Hallahan and Garland. “Essential fatty acids and their role in the treatment of impulsivity disorders” Prostaglandins Leukotrienes and Essential Fatty Acids 2004 71 (4) P211-216.

Konofal et al. “Iron-deficiency in children with attentiondeficit/hyperactivity disorder” Archives of Pediatric and Adolescent Medicine 2004158 (12) p1113-1115.

Richardson. “Clinical trials of fatty acid treatment in ADHD, dyslexia, dyspraxia and the autistic spectrum” Prostaglandins Leukotrienes and Essential Fatty Acids 2004 70 p383-390.

Richardson. “Long-chain polyunsaturated fatty acids in childhood developmental and psychiatric disorders” Lipids 2004 39 p1215-1222.

Richardson. “Omega 3 fatty acids in ADHD and related neurodevelopmental disorders” International Review of Psychiatry 200618(2) p155-172.

Schab and Trinh. “Do artificial food colors promote hyperactivity in children with hyperactive syndromes? A meta-analysis of double-blind, placebo-controlled trials” Journal of Developmental and Behavioural Pediatrics 2004 25(6) p423-434.

Stevenson. “Dietary influences on cognitive development and behaviour in children” Proceedings of the Nutrition Society 2006 65 94) p361-365.

Virmani et al. “Effects of metabolic modifiers such as carnitines, coenzyme Q10 and PUFAs against different forms of neurotoxic insults: metabolic inhibitors, MPTP and methamphetamine” Annals of the New York Academy of Science 2005 1053 p183-189.

Virmani and Binienda. “Role of carnitine esters in brain neuropathology” Molecular Aspects of Medicine 2004 25 (5-6) p533-549.