Jul. 9, 2017

The Role of Nutrition in Autism

The following is a guest post by Olive Skelly Nutritional Therapist who explores the role of Nutrition in Autism. Based in Galway City, Olive lectures at the College of Natural Medicine in Galway, as well as running her private practice, consisting of presentations to groups, and individual consultations. Olive has a personal and professional specialist interest in Nutrition and Autism. More information on Olive and her practice can be found at www.oliveskelly.com

This post is a condensed version of a blog post by Olive Skelly Nutritional Therapist. The full version can be accessed here


An Introduction to the role of Nutrition in Autism

Recent research has uncovered differences in the gastrointestinal tract of autistic children. It has been found that the majority of children with ASD display gastrointestinal symptoms, which allow undigested food to enter the blood stream.  Also differences in the composition of gut bacteria between people with ASD and those without have also been reported.

While we all have good and bad gut bacteria, the good bacteria usually out-compete the bad. When this doesn't happen, and the bad bacteria out-compete the good, these bad bacteria often produce toxins which also leak into the blood stream and are carried around the body.

This gut inflammation/leaky gut and poor bowel flora (mixture of good/bad bacteria) composition has been shown to give rise to symptoms such as food sensitivities/allergies and poor immune function.

There is also evidence available to suggest that impaired gastrointestinal function might influence brain function. The gut is lined by specialist cells which transport nutrients (and toxins) into the bloodstream. It is interesting to note that the structure of the gut is very similar to that of the blood/brain barrier, so toxins that dissolve from the gut into the bloodstream then move from the blood into the brain, contributing to symptoms such as hyperactivity, lethargy, brain fog, lack of concentration, impaired learning, poor social skills and perception, and poor social interaction.

 It has also been noted that 60 – 70 % of autistic children have an extremely limited diet often consisting of two or three items and have cravings for the very foods which damage their gut lining. It is quite rare to meet an autistic child who is not fussy with food.

All in all then, it is true to say that nutrition related factors may have an important role to play in the management of ASD and its symptoms

It is important therefore, to incorporate a diet that will reduce inflammation, heal and seal the leaky gut and enhance the growth of the beneficial bacteria in the gut. This gut healing diet also known as the GAPS diet was developed by Dr Natasha Campbell McBride. It incorporates the simplest foods for the body to digest so that the gut can heal and recover completely.


What to avoid and what to include: An Overview

It is best avoid all the foods that are difficult to digest. Grains and leguminous (beans, soya beans, peas etc.) foods, contain substances which damage the gut. These children have already got damaged guts and therefore cannot handle these foods, they are unable to digest them, so they have to be removed for a long enough time for those specialist cells to rebuild new layers in the gut, and repair themselves. It may take a couple of years. The younger the child, the quicker they recover. Adults take longer than children. But the good thing about this diet is you don’t have to stick to it for the rest of your life. You stick to it for a period of time until the gut is healed and then you can gradually start reintroducing other foods and start eating in a more versatile way.


Foods to avoid:

  • All grains. This includes wheat, rice, rye, oats, corn, maize etc
  • All starchy vegetables including potatoes, sweet potatoes, parsnip
  • Starchy beans and peas such as soy beans, chickpeas, bean sprouts
  • Lactose and anything made out of it including shop bought yoghurt and buttermilk
  • Sugar and sweeteners
  • All processed food and food additives.


Recommended Foods:

  • All kinds of meat
  • All fish
  • Organ meats – such as liver, kidney
  • Organic eggs
  • Natural fats - egg yolk, cream, butter and animal fats. Animal fats are the most important fats for humans to eat, something that the majority of people find  difficult to understand, because we grew up in a society of fat phobia and cholesterol phobia. But if you look at the structure of human cells, and of cell membranes, about half of the fats they are made from, are saturated. Coconut oil and palm oil are also important. They are largely saturated but their value is also in the specific fatty acids which are antimicrobial, antiviral, anti candida, and anti fungal. So coconut oil can be used as an anti fungal supplement and can also help with sugar cravings
  • Non-starch vegetables – This includes all vegetables apart from potatoes, sweet potatoes and parsnips
  • All ripe fruit including dried fruit - unripe fruit is full of starches which are difficult to digest. As fruit ripens, the starches get broken down into simple sugars and are then easier to digest.
  • Nut and seeds
  • Fermented dairy – such as yoghurt. When we ferment milk, we add fermenting bacteria which breakdown the lactose so well fermented dairy products are in fact lactose free. Fermented dairy products are pre digested and are therefore very easy for a damaged digestive tract to handle. However there is a small percentage of people who are allergic to dairy, and should therefore omit dairy from the diet.
  • Cold extracted honey is the only sweetener allowed

In this diet everything that the child or adult eats has to be cooked at home from fresh ingredients. No takeaways, no eating out because you cannot guarantee what has been put into that food or how the food has been cooked.


If you are interested in learning more about this topic, I will be running weekend courses, in autumn, in various venues in Ireland, explaining this concept in more detail, as well as practical demonstrations, menu plans etc.

If you are interested in learning more, just click on the link below to express your interest, and we will let you know dates and venues nearer the time.


 Yes I may be interested in learning more about Nutrition and Autism

(Clicking the above link will open a new webpage.)


The information on this post is strictly educational and the opinion of Olive Skelly Nutritional Therapy; therefore it should not be used to diagnose or treat any medical condition. Nutritional Therapy is not a substitute for medical advice or treatment and if you have any concerns regarding your or another person’s health please contact your GP, or healthcare professional for advice as soon as possible. Furthermore if you are suffering from any health condition please seek medical advice before following any of the recommendations in the blog post and/or website.