Autism is a lifelong developmental disability that affects how a person communicates with and relates to other people, as well as affecting how they make sense of the world around them. Autistic children frequently have serious behavioural disturbances, such as outbursts of aggression, tantrums and in extreme cases exhibiting self-injurious behaviour. These behavioural problems can compromise both educational and developmental progress. Findings from studies of major neurotransmitter systems known to play a role in normal growth and development of the brain strongly suggest that neurochemical factors could play a major role in autism. As such, pharmaceutical treatments for autism focus on modulating neurotransmitter levels known to play a role in the symptoms of autism including serotonin, dopamine and noradrenaline.
Attempts to treat autism with pharmaceuticals have had limited success, in part because the associated side effects can mask or outweigh any potential benefits. Increasing numbers of studies are showing that daily supplements of vital nutrients, such as essential vitamins, minerals, specific amino acids and omega-3 fatty acids often effectively reduce patients’ symptoms, because they are directly converted into the neurotransmitters that pharmaceuticals aim to chemically induce.
Diet quality, which can be deﬁned in terms of energy density, can have a profound impact on neurotransmitter function. Western diets are typically comprised of energy-dense, nutrient-poor foods, such as those high in reﬁned grains, added sugars and added omega-6 fats, and feature highly in a poor quality diet. The introduction of intensive farming methods, food processing, refining and the use of pesticides, herbicides and fertilizers has led to cheaper, highly available foods, some of which are of poor nutritional value because they are essentially stripped of their nutritional content. In contrast, low energy-dense foods, such as ﬁsh, fresh vegetables and fruit, which have a high content of vitamins, minerals, and omega-3 fatty acids, are characteristic of better quality diets.
For example, the central nervous system is rich in highly unsaturated fatty acids, which cannot be synthesised by the human body but must be supplied by the diet. These highly unsaturated fatty acids are essential for normal brain development and function and play a key role in neurotransmitter regulation, including those involved in autism. Dietary consumption of the long-chain omega-3 fatty acid EPA, commonly found in fish and fish oil, is thought to modify the risk for certain adult neuropsychiatric disorders and neurodevelopmental disorders. There is also increasing evidence that fatty acid deficiencies or imbalances may contribute to childhood neurodevelopmental disorders, including attention-deficit/hyperactivity disorder, dyslexia, dyspraxia, and autistic spectrum disorders. Parents of children with autism who have supplemented their children with omega-3 EPA have reported improvements in general health, sleeping patterns, cognitive and motor skills, concentration, eye contact, and sociability, as well as reductions in irritability, aggression and hyperactivity.1,2
Other dietary interventions that have been shown to be beneficial in the management of autistic symptoms include supplementing with essential vitamins and minerals such as zinc, magnesium and several of the B vitamins known to act as co-factors in the production of neurotransmitters. Deficiencies in those nutrients that are commonly stripped from foods are becoming commonplace in the developed world.
The impact of nutritional deficiencies can have profound effects on most physiological and metabolic pathways. Given the lack of efficacy and the side effects associated with many pharmaceutical interventions, it is not surprising that patients are looking at diet as a natural method of modulating the symptoms of autism.
- Bell JG, Miller D, MacDonald DJ, MacKinlay EE, Dick JR, Cheseldine S, Boyle RM, Graham C, O’Hare AE. (2010) The fatty acid compositions of erythrocyte and plasma polar lipids in children with autism, developmental delay or typically developing controls and the effect of fish oil intake. Br J Nutr. 103:1160-7.
- Amminger GP, Berger GE, Schäfer MR, Klier C, Friedrich MH, Feucht M. (2007) Omega-3 fatty acids supplementation in children with autism: a double-blind randomized, placebo-controlled pilot study. Biol Psychiatry. 61:551-3.