If you are reading this it is likely that you are a parent of a child who has recently been diagnosed with autism or one of the other disorders that falls under the umbrella of the autistic spectrum disorders (ASDs). Parents in a similar situation to you often describe an awful feeling of frustration following diagnosis - there are few (of any) pills or potions that your doctor can provide to treat the symptoms of your child's disorder; and waiting lists for behavioural and educational interventions can be long - if you are lucky enough to live in an area where they are available.

Many parents in your situation 'google' interventions for ASDs and come across hundreds of sites and books supporting the use of diets and supplements.  The number of different interventions recommended can be overwhelming, and the advice from different organisations is often contradictory. Most organisations suggest that trialling one or more dietary manipulations is a relatively low risk intervention you can offer your child, with the pay-off of almost miraculous changes in some children. However, few of the authors of these sites and books are from a (reputable) medical or nutritional background.

Having had a number of years experience of guiding parents through the evidence (or lack of) for these interventions, the author of this site set up these pages to share her knowledge with those who do not have access to a dietitian, and impartially help you make an informed and above all a safe choice of "biomedical intervention" for your child.

About the author

Zoe Connor is a registered dietitian - she completed 2 years post-graduate training and abides by a strict code of conduct. Dietitians are the only nutrition professionals whose standard of education is strictly regulated by a government body in the UK.  Zoe has undertaken further post-graduate training to obtain a masters degree, and also to specialise in paediatric nutrition. She has worked in the NHS on and off since 2001, and has also autism awareness trainign by the NAS, and has worked closely with local parent support groups. She is an "open-minded sceptic" when it comes to nutritional interventions for ASD - she rarely recommends them but does empathise with and supports parents who try them.  Read more about Zoe here>

About ASD

Every child with an ASD is an individual - some thrive in mainstream education, and have no other medical or developmental issues; other children have one or a myriad of extra challenges including learning disabilities, ADHD, epilepsy, antisocial behaviour, self-harming behaviour, sleep disturbances, bowel problems and physical disabilities. What autism is, its characteristics are and educational and behavioural treatments available are described further on another page of our site here>.  

ASD symptoms that diet may help with

There are many reports that changing a child's diet can help with all different aspects of their disorder - communication, eye-contact, sleep, toiletting, bowel problems, skin condition, attention span, or problematic behaviour.   

Who can advise me on the best diets to try?
 

As you will read further on on this page, there are many different suggested dietary interventions for ASD, but there is not enough evidence yet for any of us to know whether any of them can help with ASD.

It might be that further research shows that certain dietary interventions work for a particular group of children with ASD - such as children with bowel problems, or children who showed no ASD traits until they were 2 or 3 years old - but until then, no-one is likely to be able to advise you on which diets to try.  Unfortunately there are no reliable tests either. 

It may seem that there are many people who report their children have improved beyond belief on certain diets or vitamin tablets: However, properly conducted scientific trials are really needed because it is so difficult to separate a change in a child's diet with all the other changes that my be going on in their lives - did they start a new behavioural intervention around that time, or a new medication, or just go through a 'developmental spurt'.

Changing a child's diet involves so many other changes in behaviour that these changes in themselves may be to blame rather than just the diet - eg a parent cutting out a food group would have to be stricter with saying no to favorite foods - these increased boundaries may help a child to feel more secure and so behave better!! Also, when a child cuts out a food group they may have also cut out other foods that they are reacting to - eg a child cutting out gluten may also cut out brightly coloured icing on cakes that their parent hadn't realised they were reacting to, or another child may usually drink pints of milk a day in place of real food, and when cutting out milk, they would start eating a bigger range of foods, which would improve their nutrition, and then could improve their behaviour.

Does that mean I have to do it on my own?

Nope - you can enlist the support of your doctor and or dietitian even if they do not recommend the trial of any dietary interventions. Make sure you discuss any dietary trials with your doctor before implementing them - changing a child's diet may seem safe and harmless, but childhood is a critical time for brain and body growth, and these rely on balanced nutrition.  Your doctor may want to do test such as for iron deficiency anaemia or Coeliac disease before you trial any changes, and they can check that any vitamin or mineral doses you are trying are safe. 

Your doctor may also refer you to a dietitian (or you could refer yourself), who can help to monitor your child's growth and assess your child's diet to make sure they are not missing out on any vital nutrients. A dietitian with experience in allergies will also be able to guide you on safely and practically cutting out any food groups you choose to trial, and give you support on foods you can use to fill the gaps that those food groups leave. 

Some doctors and dietitians make discourage you from trialling dietary changes - especially in children who are not growing well already - they may advise you to wait until your child's nutritional intake and growth are better before putting any extra barriers to a balanced diet in place.

Which diets are there to help with autism?
 
There are lots of different diets suggested by different organisations and books. They can be split into exclusion diets, and taking nutritional supplements.

Exclusion diets:

The most common are to avoid gluten and casein (proteins commonly found in wheat, rye, oats and barley, and milk).

Others include avoiding chocolate, yeast, sugar, citrus fruits, salicylates (a natural compound found in many fruits and vegetables), fruit juice, bananas, aspartame (an artificial sweetener), MSG (a flavour enhancer), nitrates and nitrites (preservatives) or food colourings; the elimination of a number of different artificial additives and foods containing salicylates (the Feingold Diet);  rotation of different foods in the diet on different days; eating a diet of natural foods plus other foods thought to have special properties (such as The Body Ecology Diet), or eating a diet low in a specific food group (such as The Specific Carbohydrate Diet™).

Unfortunately, as we've said before, all of these are experimental interventions - none are actually proven to help.

Nutritional supplements ("biomedical interventions"):

Some organisations suggest that taking high doses of different vitamins and minerals can help with ASD, these include Vitamin A, Vitamin B3, Vitamin B6, Vitamin C, Folic Acid, Calcium, Magnesium and Zinc.  Some also suggest fish oils, evening primrose oils or cod liver oil. 

Again, there is no solid evidence that any of these are needed or useful for a child with ASD.

Is there any risk of harm to your child's health in trying these diets or supplements?

Exclusion diets:

Yes, possibly - restricting a child's diet without the expert advice and supervision of a qualified nutrition expert (a registered dietitian) can sometimes lead to nutritional deficiencies and compromise a child's growth.

For example, cutting out gluten can cause a child's diet to be low in fibre, and cause constipation, which in turn can lead to a drop in appetite and poor growth.  If a child is not willing to eat gluten-free substitutes, then their diet can also be low in overall calories, causing them to grow poorly, or even lose weight.

Cutting out milk and dairy products can lead to a low calcium intake, which in severe cases can cause weak bones (rickets).

The more foods that are cut out of a child's diet, the higher the risk is of an inadequate nutritional intake.

If your child is a very selective or picky eater, restricting their diet further can also put them at further risk of nutritional deficiencies.  Some organisations suggest that following a special diet for ASD can result in a child eating a more varied diet, but this is unfortunately often not the case.

Diets restricting major food groups such as all carbohydrate-rich foods are not recommended for children unless under close medical or dietetic supervision.  Following such a diet long-term would only recommended if it results in clear improvements in behaviour or other symptoms which outweigh the risks of such a restrictive diet.  Even then it would be best to slowly reintroduce the restricted foods until the diet is more varied.

Nutritional supplements:

Yes, possibly - it is not recommended for adults let alone children to take high doses of any individual vitamins or minerals unless they have a specific need for them.  There is no good quality evidence that children with ASD have any specific higher needs for any of these supplements than the general recommended doses from a varied diet.  

Vitamins, minerals and some fatty acids are all vital for good health in small doses, and it is popular in some nutrition circles to extrapolate that to mean that high doses would be even better for you.  However, it is known that the human body doesn't work like that - one famous example is a study of antioxidant vitamins given to smokers - the idea was that a high dose would protect against cancer, as we know that normal doses help to mop up free radicals which could increase the risk of cancer.  However the high dose vitamins in fact increased the risk of cancer, so much so that the study had to be stopped early.

Government agencies take great care in setting the safe upper doses for vitamins and minerals based on the current available evidence, and care should be taken not to exceed these, especially in children, where long term effects are poorly studied.  Current recommended doses of different vitamins and minerals are available on the foods standards agency website www.foodstandards.org.

Some organisations recommend doses of vitamin B6 for children with ASD (up to 1000mg per day) which far exceed the set safe limit (10mg/d for adults). Taking high doses of this vitamin (more than 200mg/day) has been linked to neuropathy (muscle pain and weakness), and more than 2000mg/day to irreversible nerve damage (in adults) in a small number of adults. It is true that not everyone may experience these side effects, but you may want to consider whether your child could communicate any feelings of neuropathy to you, if they were to experience them.

What about a multivitamin and mineral supplement? 

A multivitamin and mineral supplement containing up to the RNI (recommended nutrient intake) of nutrients for your child's age is a safe option if you want an 'insurance policy' that your child is meeting their requirements - your local pharmacist should be able to recommend an appropriate one.  Basic chemist's own brands are affordable and just as effective as the more expensive brands.

If you don't feel your child eats a varied diet, you might want to see a dietitian who is skilled in assessing your child's intake and recommending appropriate vitamin and mineral supplements (or food choices) on an individual basis.

What tests are available to see if my child would benefit from a special diet?

The only recommended test is a blood test available through the NHS for Coeliac disease - a medical intolerance to the protein gluten which can result in tiredness, diarrhoea, constipation, headaches, poor growth or sometimes no obvious symptoms at all. Coeliac disease is common in the UK, and following a strict gluten free diet is the recommended life-long treatment. The test for Coeliac disease is only useful if your child is currently eating gluten - so it is best to have this test before starting a gluten-free diet.  Is the test comes back positive, your doctor may recommend a further test - a gut biopsy to confirm the diagnosis.  The advantage of getting tested is that you then know definitively that your child needs to avoid gluten, and can get some gluten-free products prescribed on the NHS.

Unfortunately, there are no other reliable tests available either privately or on the NHS that can determine if your child would benefit from any of these diets. There are a couple of tests carried out on the NHS to help to diagnose severe food allergies (skin prick tests and blood RAST tests) - however these are only really useful to point to foods that can cause immediate reactions such as a life-threatening anaphylaxic reaction to nuts. None of the blood, hair, electromagnetic or alternative tests available privately have been shown to have any reproducibility or efficacy.

Urine tests commonly available for children with ASD are unfortunately unproven to have any connection with food intake or any food intolerance.
 
Some things to think about before trialling any dietary changes
 
1. Do you have the time and energy?

Following a restrictive diet can be time-consuming, and it can be difficult to cut favourite foods out of a child's diet. Some families prefer for the whole family to follow the same diet, so their child does not feel singled out. This can be a huge undertaking, but once you are into a routine it becomes much easier.

2. Do you have the money?

When cutting out major components of the diet such as gluten and casein, suitable replacements for these foods are often more expensive than the regular products.  Gluten-free products can only be prescribed to those diagnosed with Coeliac disease or  a related skin disorder dermatitis herpatiformis.

What about fish oils?

Omega 3 fatty acids (omega 3) are proven to improve brain development in foetuses and babies and to protect against heart disease in adulthood.  There is research being done to see if they help with learning and behaviour. 

There have been some studies to investigate whether high doses of omega 3 oils as a supplement can help children with their concentration at school and even improve the symptoms of children with attention deficit hyperactivity disorder (ADHD) or ASD.  These studies are as yet inconclusive, and it is not clear what precise dose of omega 3 is needed, and what balance of essential fats (known as EPA and DHA) are best.  Researchers feel that these high doses take 3 months of daily supplements before their full effects are seen.  High dose supplements can be quite expensive.

UK government recommendations are that we all should get omega 3 from eating 2 to 4 portions of oily fish a week. Girls and women of childbearing age are recommended to have no more than two portions of oily fish a week, to reduce exposure to toxins sometimes present in oily fish that can affect future unborn babies.  Children also shouldn't eat shark, swordfish and marlin, because they contain relatively high levels of mercury, which might affect a child's developing nervous system.

Examples of omega-3-rich oily fish are: Mackerel, Kippers, Pilchards, Trout, Salmon, Sardines, Herring, Eel, Whitebait, Anchovies, Bloater, Cacha, Carp, Hilsa, Jack fish, Katla, Orange roughy, Pangas, Sprats, fresh or frozen Tuna (omega 3 oils are extracted in tinning in the UK)
 .
If your child does not eat fish there are other foods containing omega 3s:
- dark green leafy vegetables
- granary bread and other wholegrain cereal products
- linseeds/flax, walnuts, pecans, peanuts and almonds (avoid whole nuts in children under 5 years or if your child is at risk of allergies)
- omega 3 enriched foods, e.g. Columbus eggs, some margarines, some milks
- olive oil, Rapeseed/Canola oil, linseed/flax oil and walnut oil
 
If your child does not like oily fish or any of the foods listed above, then they may benefit from a fish oil or plant based omega 3 oil supplement - but consult your doctor before taking a supplement if your child is on medication or has a medical condition such as epilepsy, diabetes, or haemophilia.
  
There are many different omega 3 and fish oil supplements on the market.  When choosing a supplement watch out that:
- It is suitable for the age of your child
- It is not too high in vitamin A as this can become toxic in large amounts, especially in children
- It has Vitamin E (tocopherols) to help the body to use the omega 3 and improve the supplement's shelf life.
- It is a reputable brand -all fish oils supplements in the UK have to have been purified to reduce pollutants

Where to start
 
A systematic approach to any changes in your child is key to help to judge whether it has helped - in essence you have to take a scientist's approach: if you cut out gluten at the same time as starting a new medication, how will you know which one has helped? Or if you try a milk free diet at the same time as starting fish oil capsules - again, how will you know?

Many parents don't take this approach - they are keen to implement as many possible interventions at a time as early as possible - which is really understandable, but then they are left 3 or 4 years down the line struggling with an unmanageable diet, and not quite sure which aspects of it (if any) are useful. (If you are reading this and already in this position, you can reverse the process in a systematic way - stop the dietary interventions one at a time to see if there is any adverse effect on your child)
 
So, if you do make a decision to follow any dietary interventions, after first checking with your doctor it is ok and ideally enlisting the help of a dietitian, plan the changes carefully: Only make one dietary change at a time, and try not to make dietary changes when your child is starting other treatments- e.g. an intensive behaviour programme or change in medication.  Then aim to objectively monitor your child's symptoms or behaviour before during and after the intervention - you may not think you need to do this, but it is surprising how hard it is to think back a few weeks to how many tantrums or bowel movements or night wakings your child was having then. Having it written down helps you to see concretely whether the intervention has been useful and is a great tool for convincing sceptical health professionals, teachers, and family members that it is worth keeping the dietary change up (if that is what you find)
 
So, if you are approaching this like a scientist, try to implement the diet in these 3 stages:

   1. Baseline monitoring

Monitor your child's behaviour and bowel habit carefully for a couple of weeks on their normal diet  - record this in a diary, and try and quantify it - eg behaviour on a scale of 1 to 10 with 1 being the best and 10 being the worst you've seen; or number of loose bowel movements a day.

   2. Strict implementation of dietary change

Make your chosen dietary change (starting a supplement or cutting out a food) for a set time. Two weeks is often more than enough time to see any bowel or behavioural changes from excluding a food, but some parents prefer at least a month, just to make sure. The theory is that omega 3 supplements take three months to work. Continue your diary of behaviour and bowels, and note in it any slip-ups in the diet, or other changes in your lifestyle or treatment programme. Try to follow your chosen intervention strictly over this trial time - if you are cutting out milk, you don't just need to cut out the obvious sources of milk - such as yogurt and cheese, but also the traces of milk found in lots of other processed foods - a dietitian can help you identify these in your child's diet.  

   3. Stop!

The hardest part for a lot of parents. Even if you are sure your child has improved on their new diet, you won't know for sure until you stop the diet and see whether the improvements reverse - e.g. if your child is no longer having loose bowel movements whilst avoiding milk, give him a little bit of milk again daily, increasing the amount each day - if he is fine then it was a coincidence that he got better on the diet; If the loose stools come back a day or two after restarting milk, then it is quite convincing that he has a milk intolerance. 

Keep on with your bowel and behaviour diary, and if there is a clear deterioration in your child's symptoms, weigh up this with how difficult it was to implement the diet, and if the difficulties of the diet are outweighed by the benefit to your child, reinstate the diet. Then, consult with your doctor or dietitian for long-term support (and try stopping the diet every six months to a year)

    4. Long term support

If you decide to continue with a dietary restriction long-term, a dietitian can help to ensure that your child's diet is adequate - you probably need to continue seeing a dietitian regularly - yearly at least.

Book shop

Buy our comprehensive guide Help with a gluten-free and milk-free diet for autism and other disorders here>

                        <<Other ebooks coming soon>>

• A guide to considering diet or biomedical interventions as a treatment for autism or ASD (PDF file, 218KB)
• A guide to considering a gluten-free and casein-free diet for the treatment of autism (PDF file, 123KB)
• ASD symptom monitoring chart (Word file)
• ASD symptom monitoring chart (PDF file, 46KB)
• Diet in the treatment of autism - a summary of the evidence, Nov 2006 (PDF file, 138KB)
• Autism and Diet food fact sheet (British Dietetic Association website)

Page first published: September 17th 2006, last updated: January 7th 2009.