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Diet and vitamins: therapeutic approaches

This section has been written to provide information on a particular intervention/approach and any research connected with it, not as a recommendation. The outcome of any approach will depend on the needs of the individual, which vary greatly, and the appropriate application of the intervention. An intervention that may help one individual may not be effective for another. It would therefore not be appropriate for The National Autistic Society (NAS) to recommend any one particular practice or therapy.

Introduction

Interest in the use of diet and vitamins as a therapeutic approach for autism is high. Millward et al (2008) cite evidence of widespread use by parents of complementary and alternative therapies, including diet, for their children with autism. However, there is a lack of evidence to support the use of diet as an effective treatment for autism (Millward et al, 2008; Connor, 2006). Even where evidence is available, it is important to note that dietary approaches cannot be expected to help all individuals with a particular diagnosis: they should be viewed as complementary to other methods of management, rather than as a primary or stand alone treatment (Richardson, 2003a, Richardson, 2006).

This information sheet provides information on a range of approaches using diet or vitamins for people with autism. It focuses on approaches for which there is peer-reviewed research available. Peer-reviewed research is scientific, academic work which has been evaluated by others working in the same field (Oxford Dictionary of English, 2nd edition).

For information on other dietary approaches please contact the Autism Helpline (tel: 0845 070 4004, open Monday-Friday, 10am-4pm) or access Autism Data, our database of publications in the field of autism. Autism Data is available online at www.autism.org.uk/autismdata

Safety

Before embarking on any change of diet or use of supplements, consultation with a general practitioner (GP) or registered dietitian is strongly recommended. See below for details of how to find a registered dietitian.

Vitamins and supplements can be toxic in high doses. The Food Standards Agency website (www.eatwell.gov.uk/healthydiet/nutritionessentials/vitaminsandminerals/) and The British National Formulary website (www.bnf.org.uk/bnf/) offer information on vitamins and supplements, including safe upper levels for supplementation.

The British Dietetic Association (BDA) warn against excluding foods without making sure that the diet remains balanced as this may lead to dietary deficiencies, weight loss and poor growth (Connor, 2006).

Finding a registered dietitian

The BDA advise that most people will be able to see a registered dietitian in the National Health Service (NHS) following referral by a GP, health visitor or other medical staff. A registered dietitian will be appropriately trained and registered with the Health Professions Council (HPC). You can search the HPC website at www.hpcheck.org/

For details of registered dietitians in private practice visit Dietitians Unlimited, the website of the BDA's Freelance Dietitian Group: www.dietitiansunlimited.co.uk/ For further information on the BDA visit www.bda.uk.com/

References

Connor, Z. (2006) Diet and autistic spectrum disorder. Birmingham: British Dietetic Association

Millward, C. et al (2008). Gluten and casein-free diets for autistic spectrum disorder. Cochrane Database of Systematic Reviews, 2, CD003498 Available to download from: www.mrw.interscience.wiley.com/cochrane/clsysrev/articles/CD003498/pdf_fs.html

Richardson, A. J. (2003a). The role of omega 3 fatty acids in behaviour, cognition and mood. Scandinavian Journal of Nutrition, 47(2), pp. 92-98

Richardson, A. J. (2006). Omega-3 fatty acids in ADHD and related neurodevelopmental disorders. International Review of Psychiatry, 18(2), pp. 155-172

Soanes, C. and Stevenson, A. (eds.) (2003). Oxford Dictionary of English (2nd ed.). Oxford: Oxford University Press. 0198613474

Vitamin B6 (pyridoxine) and magnesium

Theory behind the treatment

Researchers have noted some children with pervasive developmental disorders (PDDs) such as autism resemble children with pyridoxine-dependent epilepsy, an impairment of vitamin B6 metabolism treated with high doses of the vitamin (Kuriyama et al (2002).

Research

Nye and Brice (2005) conducted a review of the research literature concerning combined vitamin B6 and magnesium treatment for autism spectrum disorder (ASD). They state that studies investigating the effect of vitamin B6 in improving the behaviour of children with autism have been reported for over three decades. However, only three studies met the inclusion criteria of their review. These studies are Kuriyama et al (2002), Findling et al (1997), and Tolbert et al (1993).

In the study conducted by Kuriyama et al (2002) eight children were randomly assigned to either an experimental or placebo condition. This means that the experimental group were given vitamin B6 supplements, while the placebo group were given a harmless supplement containing none of the chemical elements of the vitamin B6 supplement. None of the participants knew whether they were receiving the vitamin B6 supplement or the placebo. This enables researchers to more accurately measure the effects (if any) of the substance being studied. The dose for the study was 100 milligrams (mg) once a day for two weeks. Kuriyama et al (2002) measured the intelligence and social intelligence of the participants and reported that vitamin B6 was associated with an increased performance on language tests. However, Nye and Brice (2005) analysed the study data reported by Kuriyama et al (2002) and found no significant effects for any of the measures reported.

In the study conducted by Findling et al (1997) ten children were administered with 30 mg of vitamin B6 per 1 kilogram (kg) of body weight up to a maximum of 1 gram a day, and 10 mg of magnesium per kg of body weight up to a maximum of 350 mg a day. They conducted single-blind and double-blind placebo trials over ten weeks. Single-blind means the trial has been conducted with either the participants or the researchers unaware who is taking the placebo. Double-blind means the trial has been conducted with both the participants and the researchers being unaware who is taking the placebo.

Findling et al (1997) reported that vitamin B6 and magnesium supplementation was ineffective in reducing autistic behaviours. They concluded that their study raises doubts about the clinical effectiveness of high doses of vitamin B6 and magnesium as a treatment for ASD (Findling et al, 1997).

Nye and Brice (2005) analysed the study data reported by Findling et al (1997) and found a significant difference in the behaviour of the participants who received vitamin B6 and magnesium supplementation as compared with the placebo group at four weeks after treatment. They concluded that that data reported by Findling et al (1997) was in conflict with the conclusion reported by Findling et al (1997). However, when Nye and Brice sought further information from Findling et al it was reported to be unavailable (Nye and Brice, 2005).

In the study conducted by Tolbert et al (1993) twenty children took part in a 30-week double-blind trial. Some participants received no treatment, while some received 200 mg of vitamin B6 and 100mg of magnesium per day for some of the trial period and a placebo for some of the trial period. Where high doses of vitamin B6 and magnesium had previously been administered, peripheral neuropathy had been reported (see the section headed 'Safety' for further information). The study by Tolbert et al (1993) sought to measure the effectiveness of a reduced dose to counter these side effects. They concluded that to reduce the high dose of this treatment had no therapeutic effect. Nye and Brice (2005) reported that they were not able to analyse the data reported by Tolbert et al (1993) as sufficient data was not available.

Conclusion

Nye and Brice (2005) conclude that use of vitamin B6 for improving the behaviour of people with autism cannot currently be supported. They report three reasons for this: firstly, the small number of studies meeting their criteria for analysis; secondly, the methodological quality of the studies (the methods used); and thirdly, the small sample sizes (the number of participants in the trials). Nye and Brice (2005) suggest that people with autism may need longer treatment periods to benefit from the treatment, and argue that future research should address this.

Safety

The British National Formulary (2008) reported sensory neuropathy as a side effect of high doses of vitamin B6 supplementation for extended periods. Peripheral neuropathy, a form of sensory neuropathy, is a loss of feeling in the arms and legs. Generally these symptoms are reversible so the symptoms stop when supplementation stops. However in a few cases where high doses have been taken, especially for more than a few months, the effect has been irreversible (Food Standards Agency, 2008). A daily 10 mg dose is considered safe but long-term doses of 200 mg or more per day have been associated with neuropathy. Furthermore the safety of long-term supplementation with doses of above 10 mg per day has not been established (British National Formulary, 2008). For magnesium supplementation, 400 mg or less per day is considered safe (Food Standards Agency, 2008).

Where can I find vitamin B6 and magnesium supplements?

These and other supplements are widely available in pharmacies, health food shops and supermarkets. Pharmacies will offer access to a pharmacist should you wish to seek advice.

References

British National Formulary (2008). Available at www.bnf.org.uk/bnf/

Findling, R. et al (1997). High-dose pyridoxine and magnesium administration in children with autistic disorder: an absence of salutary effects in a double-blind, placebo-controlled study. Journal of Autism and Developmental Disorders, 27(4), pp. 467-478
Available from the NAS Information Centre

Food Standards Agency (2008). Available at
www.eatwell.gov.uk/healthydiet/nutritionessentials/vitaminsandminerals/

Kuriyama, S. et al (2002). Pyridoxine treatment in a subgroup of children with pervasive developmental disorders. Developmental Medicine and Child Neurology, 44(4), pp. 283-286

Nye, C. and Brice, A. (2005). Combined vitamin B6-magnesium treatment in autism spectrum disorder. Cochrane Database of Systematic Reviews, 4, CD003497
Available to download from www.mrw.interscience.wiley.com/cochrane/clsysrev/articles/CD003497/pdf_fs.html

Tolbert, L. et al (1993). Brief report: lack of response in an autistic population to a low dose clinical trial of pyridoxine plus magnesium. Journal of Autism and Developmental Disorders, 23(1), pp. 193-199
Available from the NAS Information Centre

Fatty acids

Theory behind the treatment

Omega-3 and omega-6 fatty acids play key roles in brain development and function (Richardson, 2001; Richardson, 2003a; Richardson, 2003b; Richardson and Ross, 2003). Research suggests that imbalances or deficiencies in highly unsaturated fatty acids (HUFA) of the omega-3 and omega-6 series may contribute to a range of behavioural and learning difficulties, and neurodevelopmental disorders including autism spectrum disorders (Bell et al, 2000; Richardson and Ross, 2000; Richardson, 2001; Vancassel, 2001; Richardson, 2003a; Richardson and Ross, 2003; Richardson, 2004; Richardson, 2006).

Research

We are only aware of one peer-reviewed randomised, controlled trial of fatty acid supplementation for autism at the time of writing. Amminger et al (2007) conducted a small double-blind, placebo-controlled pilot study with 13 children with an ASD who had severe tantrums, aggression, or self-injurious behaviour. Participants were given 1.5 g of omega-3 fatty acids per day (comprising 840 mg eicosapentaenoic acid (EPA) and 700 mg docosahexaenoic acid (DHA) or a placebo over a six-week period. Using the Aberrant Behaviour Checklist (ABC) as an outcome measure, the researchers observed an advantage of omega-3 fatty acids versus placebo in terms of hyperactivity and stereotypy. Stereotypy is defined as repetitive actions lacking curiosity and creativity (Trevarthen et al, 1998).

Politi et al (2008) carried out an open label study of omega-3 fatty acid supplementation with 19 adults with autism. An open label study is one in which the treatment is known to both participants and researchers. The participants were administered with two fish oil capsules per day comprising 930 mg of EPA and DHA plus 5 mg of vitamin E. The treatment period lasted for six weeks followed by a further six-week period of observation. Politis study did not involve a control group. A control group is a group of participants who do not receive the treatment. A caregiver questionnaire, and the Rossago Behavioural Checklist were used as outcome measures. Politi et al (2008) observed no significant improvements in the severity and frequency of problematic behaviours during either the treatment or observation periods. They advocate more studies with larger sample sizes to further investigate the efficacy of fatty acids as a treatment for autism.

Though not autism-specific, readers may be interested in the findings of Richardson and Montgomery (2005). They conducted a randomised, controlled trial of dietary supplementation with omega-3 and omega-6 fatty acids, compared with placebo, among 117 children with developmental co-ordination disorder (DCD). For three months participants were given six capsules per day of either omega-3 and omega-6 fatty acids or placebo. The daily dosage for fatty acids was 558 mg EPA and 174 mg of DHA for omega-3 fatty acids, and 60 mg of ã-linoleic acid plus 9.6 mg of vitamin E for omega-6 fatty acids. After three months there was a one-way crossover of placebo to active treatment for a further three months. That is those participants who had received the placebo for the first three months were then given the fatty acids for the following three months. Significant improvements for active treatment versus placebo were found in reading, spelling and behaviour. Though the study focussed on DCD specifically, the authors suggest that the results may be more widely generalised.

Further research, particularly with specific reference to autism is needed to add to our knowledge in this area. In particular, the optimal dosage and combination of fatty acids are at present unknown and further studies are needed to establish both the optimal composition and dosage (Richardson, 2006; Richardson and Montgomery, 2005).

Conclusion

Amminger at al (2007) argue that their study provides preliminary evidence that omega-3 fatty acids may be an effective treatment for autism. However, this is the only peer-reviewed randomised, controlled trial of fatty acid supplementation specific to autism that we are aware of. Furthermore, the sample size was small involving only 13 participants. The open label study by Politi et al (2008) found no significant improvements in behaviour. Again the sample size was small at 19 participants and the study did not involve a control group. The researchers themselves called for further studies with larger sample sizes. While research concerning fatty acid supplementation for other related conditions or those with some similarities to autism is interesting, further autism-specific research is required to add to our knowledge in this area.

Safety

We are not aware of any Government guidelines on fatty acid supplementation. Therefore we would suggest that you follow the recommended dosage on the packaging by your supplements manufacturer in conjunction with advice from your GP or registered dietitian.

Where can I find fatty acids?

HUFA is present in fish and seafood, nuts and seeds, and green leafy vegetables. However these nutrients can be lacking in modern diets. It is possible to increase your intake of HUFA by taking supplements. Supplements generally contain fish oils; however alternatives are available such as flax or hemp seed oil. Products may be single oils or blends and will offer varying levels of omega 3 and 6. Please check the label. Both fish and non-fish oil-based supplements can be found in pharmacies, health food shops and supermarkets. Pharmacies will offer access to a pharmacist should you wish to seek advice.

References

Amminger, G. P. et al (2007). Omega-3 fatty acids supplementation in children with autism: a double-blind randomized, placebo-controlled pilot study. Biological Psychiatry, 61(4), pp. 551-553

Bell, J. G. et al (2000). Red blood cell fatty acid compositions in a patient with autistic spectrum disorder: a characteristic abnormality in neurodevelopmental disorders? Prostaglandins Leukotrienes and Essential Fatty Acids, 63(1-2), pp. 21-25

Politi, P. et al (2008). Behavioural effects of omega-3 fatty acid supplementation in young adults with severe autism: an open label study. Archives of Medical Research, 39(7), pp. 682-685

Richardson, A. (2001). Fatty acids in dyslexia, dyspraxia, ADHD, and the autistic spectrum. The Nutrition Practitioner, 3(3), pp. 18-24, 66

Richardson, A. J. (2003a). The role of omega 3 fatty acids in behaviour, cognition and mood. Scandinavian Journal of Nutrition, 47(2), pp. 92-98

Richardson, A. (2003b). Fatty acids in dyslexia, dyspraxia, ADHD, and the autistic spectrum. Inverness: Food and Behaviour Research

Richardson, A. J. (2004). Clinical trials of fatty acid treatment in ADHD, dyslexia, dyspraxia and the autistic spectrum. Prostaglandins Leukotrienes and Essential Fatty Acids, 70(4), pp. 383-390

Richardson, A. J. (2006). Omega-3 fatty acids in ADHD and related neurodevelopmental disorders. International Review of Psychiatry, 18(2), pp. 155-172

Richardson, A. J. and Montgomery, P. (2005). The Oxford-Durham study: a randomized, controlled trial of dietary supplementation with fatty acids in children with developmental coordination disorder. Pediatrics, 115(5), pp. 1360-1366

Richardson, A. J. and Ross, M. A. (2000). Fatty acid metabolism in neurodevelopmental disorder: a new perspective on associations between attention-deficit/hyperactivity disorder, dyslexia, dyspraxia and the autistic spectrum. Prostaglandins Leukotrienes and Essential Fatty Acids, 63(1-2), pp. 1-9

Richardson, A. and Ross, M. (2003). Physical signs of fatty acid deficiency. Inverness: Food and Behaviour Research

Trevarthen, C. et al (1998). Children with autism: diagnosis and interventions to meet their needs. 2nd ed. London: Jessica Kingsley Publishers. 1853025550.

Vancassel, S. (2001). Plasma fatty acid levels in autistic children. Prostaglandins Leukotrienes and Essential Fatty Acids, 65(1), pp. 1-7

Gluten-free and casein-free diet

Theory behind the treatment

It has been suggested that peptides (compounds of amino acids linked in a chain) from gluten (present in grains and cereals) and casein (present in milk and milk products) may play a role in autism (Millward et al, 2008). Abnormal levels of peptides in the urine of some people with autism have been reported by Knivsberg et al (2003). They believe that behaviours displayed by people with autism may be explained by opioid effect processes, that is physiological effects related to urinary peptide abnormalities. Kurtz (2008) provides a simple explanation of the proposed physiological effects in which a disorder in the immune system results in undigested peptides, which irritate and increase the permeability of the intestinal lining causing peptides to flow directly into the bloodstream. This is often referred to as leaky gut syndrome. The peptides containing high level opioids, similar to heroin or morphine, cross the blood-brain barrier and cause problems with the nervous system. It is therefore proposed that by eliminating foods containing gluten and casein from the diet, eg bread, dairy, etc autistic behaviours may be reduced.

Research

Millward et al (2008) identified two randomised controlled trials of gluten-free and casein-free (GFCF) diets for people with autism meeting the inclusion criteria of their review. These are Elder et al (2006) and Knivsberg et al, reported in Knivsberg et al (2002) and Knivsberg et al (2003).

The study by Knivsberg et al involved 20 children and compared a GFCF diet with a normal diet. They used four outcome measurements: autistic traits, linguistic age, non-verbal cognitive level, and motor problems. In their second paper (2003) they used the four subscales of the DIPAB, a measure of autistic traits used in Denmark. The trial lasted for a year. Participants were pair-matched according to severity of symptoms and randomly allocated to a treatment group (those put on a GFCF diet) or control group (those put on a normal diet). Outcomes assessors were unaware to which group individual participants had been allocated. Knivsberg et al reported a reduction in autistic traits (2002), and improvements in communication and interaction (2003) for the treatment group.

The study by Elder et al (2006) involved 15 children and compared a GFCF diet with a normal diet. They used a range of outcome measures including the Childhood Autism Rating Scale (CARS), urinary peptide levels, the Ecological Communication Orientation (ECO) Language Sampling Summary and observations of parent-child interaction. The trial lasted for 12 weeks with a further six weeks crossover. Participants, parents and the investigative team (with the exception of the data manager and the dietitian) were unaware to which group individual participants had been allocated. Elder et al (2006) report that, though several parents reported improvement in their children, the data did not indicate any statistically significant findings of differences in outcome between the treatment and control groups. Millward et al (2008) praised the study by Elder et al (2006) as particularly well designed though they do recommend a wash-out period prior to the commencement of the trial proper.

Millward et al (2008) point out that exclusion diets can be inconvenient and costly. Hediger et al (2008) identified reduced bone cortical thickness for boys with autism but particularly for those on a casein-free diet.

Conclusion

Millward et al (2008) conclude that a GFCF diet cannot be recommended as a standard treatment for autism due to the limited data available. They recommend further randomised controlled trials in this area and in particular replication of the trial by Elder et al (2006) with an adequate sample size, that is more participants.

Safety

We are not aware of any Government guidelines on GFCF diets. However elimination of foods containing gluten and casein is a significant change to the balanced diet advocated by health professionals. It is therefore important to consult your GP or dietitian before embarking on such a change. Whiteley (2007) suggests that a GP will also be able to arrange routine blood tests to screen for coeliac disease and/or iron deficiency. For further information on testing for urinary peptide abnormalities contact:

The Autism Research Unit
Department of Pharmacy, Health & Well-being
Faculty of Applied Sciences
University of Sunderland
Sunderland SR1 3SD

Tel: 0191 515 2581
Email: autism.unit@sunderland.ac.uk

Where can I find GFCF foods?

As exclusion diets have become more popular it has become easier to find GFCF foods in health food stores and supermarkets though choices are still limited. It can be particularly difficult when eating out or on holiday and you may wish to phone a restaurant in advance to check they are able to cater for a GFCF diet. There are a number of personal accounts and recipes provided by people following the diet with their families that you may find helpful should you choose to embark on the diet (please see the sections headed 'Further reading: advice, personal accounts' and recipes; and 'Websites').

References

Elder, J. H. et al (2006) The gluten-free, casein-free diet in autism: results of a preliminary double blind clinical trial. Journal of Autism and Developmental Disorders, 36(3), pp. 413-420
Available from the NAS Information Centre

Hediger, M. L. et al (2008). Reduced cortical thickness in boys with autism or autism spectrum disorder. Journal of Autism and Developmental Disorders, 38(5), pp. 848-856
Available from the NAS Information Centre

Knivsberg, A. M. et al (2002) A randomised, controlled study of dietary intervention in autistic syndromes. Nutritional Neuroscience, 5(4), pp. 251-261

Knivsberg, A. M. et al (2003) Effect of a dietary intervention on autistic behaviour. Focus on Autism and Other Developmental Disabilities, 18(4), pp. 247-256
Available from the NAS Information Centre

Kurtz, L. A. (2008). Understanding controversial therapies for people with autism, attention deficit disorder, and other learning disabilities: a guide to complementary and alternative medicine. London: Jessica Kingsley Publishers. 9781843108641
Available from NAS Publications

Millward, C. et al (2008). Gluten and casein-free diets for autistic spectrum disorder. Cochrane Database of Systematic Reviews, 2, CD003498
Available to download from www.mrw.interscience.wiley.com/cochrane/clsysrev/articles/CD003498/pdf_fs.html

Whiteley, P. (2007). Dietary intervention. Communication, 41(2), pp. 22-23
Available from the NAS Information Centre

Websites

Autism File
Journal and directory with a particular focus on biomedical and nutritional issues and autism.
www.autismfile.com

Autism Medical
Website of Allergy induced Autism and Visceral, two charities dedicated to the investigation and treatment of dietary, gastrointestinal and immune issues in autism spectrum disorders.
www.autismmedical.com

Food and Behaviour Research
Charitable organisation dedicated to advancing scientific research into nutrition and behaviour.
www.fabresearch.org

nutritionnutrition
Website of Zoe Connor, dietitian and author of Diet and autistic spectrum disorder (see references under heading 'Safety').
www.nutritionnutrition.com/

Piginthekitchen
Recipe blog by a parent of a child with dietary allergies
http://piginthekitchen.blogspot.com/

Information on providers of dietary products is available on the Autism Services Directory at www.autismdirectory.org.uk

More information on interventions is available on the Research Autism website at www.researchautism.net Research Autism is the only UK charity dedicated to research into interventions in autism. The interventions section of their website provides information about a range of interventions, including what they are, what they are supposed to achieve and whether there is any supporting scientific evidence behind them.

By Stephanie Taylor

If an item is marked as available from the NAS please contact:

NAS Publications
Central Books Ltd
99 Wallis Road
London E9 5LN
Tel: +44 (0)845 458 9911
Fax: +44 (0)845 458 9912
Email: nas@centralbooks.com
Online orders: www.autism.org.uk/pubs

If you require information on other approaches please contact the NAS Information Centre.
Tel: + 44 (0)20 7903 3599 or 0845 070 4004

The National Autistic Society is the UK's leading charity for people affected by autism.