The best sources of vitamin A are breast milk, organ meats, milk fat, fish and cod liver oil, none of which are prevalent in our diets. Instead, we have formula milk, fortified food and multivitamins, many of which contain altered forms of retinol such as retinyl palmitate, which doesn’t work as well as the fish or animal-derived retinol. Megson began speculating what might happen if these children weren’t getting enough natural vitamin A 12 .
She realised that not only would this affect the integrity of the digestive tract, potentially leading to allergies. It would also affect the development of their brains, and disturb their vision. Both brain differences and visual defects have been detected in autistic children. The visual defects, Megson deduced, were an important clue because lack of vitamin A would mean poor black and white vision, a symptom often seen in the relatives of autistic children. If you can’t see black and white, you can’t see shadows. And without that you lose the ability to perceive three-dimensionality. This in turn leaves you less able to make sense of people’s expressions, which could explain why some autistic children tend not to look straight at you. Long thought to be a sign of poor socialisation, this sideways technique may in fact be the best way for them to see people’s expressions, because there are more black and white light receptors at the edge of the visual field than in the middle.
Search our evidence database andenter ‘vitamins’ or ‘minerals’ or ‘nutrients’ or ‘retinol’ and ‘autism’ into the search field for a summary of studies that demonstrate the effect of these nutrients on autism. High doses of any nutrient (even water) can be toxic so it’s best to only use high doses under qualified supervision. However, usual over-the-counter doses of vitamins and minerals are very safe. Key Action: Eat 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. One of the most significant contributing factors in autism appears to be undesirable foods and chemicals that often reach the brain via the bloodstream because of faulty digestion and absorption. Much of the impetus for recognising the importance of dietary intervention has come from parents who’ve noticed vast improvements in their children after changing their diets. The strongest direct evidence of foods linked to autism involves wheat and dairy, and the specific proteins they contain – namely, gluten and casein. These are difficult to digest and, especially if introduced too early in life, may result in an allergy. Fragments of these proteins, called peptides, can have big impacts in the brain. They can act directly in the brain by mimicking the body’s own natural opioids (such as the enkephalins or endorphins), and so are sometimes called ‘exorphins’. Or they can disable the enzymes that would break down these naturally occurring compounds. In either case, the consequence is an increase in opioid activity, leading to many symptoms we describe as autism. Researchers at the Autism Research Unit at Sunderland University have found increased levels of these peptides in the blood and urine of children with autism. Exorphin peptides are derived from incompletely digested proteins, particularly food containing gluten and casein. One of these, called IAG and derived from gluten in wheat, has been detected in 80 per cent of autistic patients. So the first problem is the poor digestion of proteins. A lack of sufficient zinc and vitamin B6 could contribute to this, as both are essential for proper stomach acid production and protein digestion, yet are often deficient in autistic children with pyroluria, as we mention above. There are many anecdotal reports of dramatic improvements in children with autism from parents who removed casein (milk protein) and gluten (the protein in wheat, barley, rye and oats) from their diet. Dr Robert Cade, professor of medicine and physiology at the University of Florida, has observed that as levels of peptides in the blood decrease, the symptoms of autism decrease. ‘If [levels of peptides] can be reduced to normal range,’ he says, ‘we typically see dramatic improvements.’ If you decide to go down this route with your child, you’ll need to take a go-slow approach. The Autism Research Unit at Sunderland University recommends a gradual withdrawal of foods, waiting three weeks after the removal of dairy foods (casein) before removing wheat, oats, barley and rye (gluten) from the diet. Initially, your child may go through ‘withdrawal’ and their symptoms may get worse for a bit. Keep a food diary and note your child’s behaviours and symptoms alongside all the foods they’re eating.
This can help to identify which of the usual suspects they are sensitive to – citrus fruits, chocolate, artificial food colourings, salicylates, eggs, tomatoes, avocados, aubergine, red peppers, soya and corn. But remember, most of the foods in this list contain valuable nutrients, too, so you’ll have to ensure that they are replaced rather than just removed. This entire process is best done under the guidance of a nutritional therapist. Search our evidence database and enter ‘allergies’ and ‘autism’ into the search field for a summary of studies that demonstrate the effect of food allergies on autism.
A possible slight worsening of symptoms if changes are made too quickly. Any major changes to the diet are should be supervised by a qualified nutritional therapist experienced in this area. Key Action: Consider testing your child for IgE and IgG food allergies and avoid those foods to which they test allergic. Alternatively, consider pursuing a wheat and dairy free diet which has proven helpful for some, but not all, autistic children.